pull in containers/image deps

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

vendor/github.com/docker/distribution/.gitignore

@@ -0,0 +1,37 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
+
+# never checkin from the bin file (for now)
+bin/*
+
+# Test key files
+*.pem
+
+# Cover profiles
+*.out
+
+# Editor/IDE specific files.
+*.sublime-project
+*.sublime-workspace

vendor/github.com/docker/distribution/.mailmap

@@ -0,0 +1,18 @@
+Stephen J Day <stephen.day@docker.com>  Stephen Day <stevvooe@users.noreply.github.com>
+Stephen J Day <stephen.day@docker.com>  Stephen Day <stevvooe@gmail.com>
+Olivier Gambier <olivier@docker.com>    Olivier Gambier <dmp42@users.noreply.github.com>
+Brian Bland <brian.bland@docker.com>    Brian Bland <r4nd0m1n4t0r@gmail.com>
+Brian Bland <brian.bland@docker.com> Brian Bland <brian.t.bland@gmail.com>
+Josh Hawn <josh.hawn@docker.com>        Josh Hawn <jlhawn@berkeley.edu>
+Richard Scothern <richard.scothern@docker.com> Richard <richard.scothern@gmail.com>
+Richard Scothern <richard.scothern@docker.com> Richard Scothern <richard.scothern@gmail.com>
+Andrew Meredith <andymeredith@gmail.com> Andrew Meredith <kendru@users.noreply.github.com>
+harche <p.harshal@gmail.com> harche <harche@users.noreply.github.com>
+Jessie Frazelle <jessie@docker.com>  <jfrazelle@users.noreply.github.com>
+Sharif Nassar <sharif@mrwacky.com> Sharif Nassar <mrwacky42@users.noreply.github.com>
+Sven Dowideit <SvenDowideit@home.org.au> Sven Dowideit <SvenDowideit@users.noreply.github.com>
+Vincent Giersch <vincent.giersch@ovh.net> Vincent Giersch <vincent@giersch.fr>
+davidli <wenquan.li@hp.com> davidli <wenquan.li@hpe.com>
+Omer Cohen <git@omer.io> Omer Cohen <git@omerc.net>
+Eric Yang <windfarer@gmail.com> Eric Yang <Windfarer@users.noreply.github.com>
+Nikita Tarasov <nikita@mygento.ru> Nikita <luckyraul@users.noreply.github.com>

vendor/github.com/docker/distribution/AUTHORS

@@ -0,0 +1,147 @@
+Aaron Lehmann <aaron.lehmann@docker.com>
+Aaron Schlesinger <aschlesinger@deis.com>
+Aaron Vinson <avinson.public@gmail.com>
+Adam Enger <adamenger@gmail.com>
+Adrian Mouat <adrian.mouat@gmail.com>
+Ahmet Alp Balkan <ahmetalpbalkan@gmail.com>
+Alex Chan <alex.chan@metaswitch.com>
+Alex Elman <aelman@indeed.com>
+Alexey Gladkov <gladkov.alexey@gmail.com>
+allencloud <allen.sun@daocloud.io>
+amitshukla <ashukla73@hotmail.com>
+Amy Lindburg <amy.lindburg@docker.com>
+Andrew Hsu <andrewhsu@acm.org>
+Andrew Meredith <andymeredith@gmail.com>
+Andrew T Nguyen <andrew.nguyen@docker.com>
+Andrey Kostov <kostov.andrey@gmail.com>
+Andy Goldstein <agoldste@redhat.com>
+Anis Elleuch <vadmeste@gmail.com>
+Anton Tiurin <noxiouz@yandex.ru>
+Antonio Mercado <amercado@thinknode.com>
+Antonio Murdaca <runcom@redhat.com>
+Arien Holthuizen <aholthuizen@schubergphilis.com>
+Arnaud Porterie <arnaud.porterie@docker.com>
+Arthur Baars <arthur@semmle.com>
+Asuka Suzuki <hello@tanksuzuki.com>
+Avi Miller <avi.miller@oracle.com>
+Ayose Cazorla <ayosec@gmail.com>
+BadZen <dave.trombley@gmail.com>
+Ben Firshman <ben@firshman.co.uk>
+bin liu <liubin0329@gmail.com>
+Brian Bland <brian.bland@docker.com>
+burnettk <burnettk@gmail.com>
+Carson A <ca@carsonoid.net>
+Chris Dillon <squarism@gmail.com>
+cyli <cyli@twistedmatrix.com>
+Daisuke Fujita <dtanshi45@gmail.com>
+Daniel Huhn <daniel@danielhuhn.de>
+Darren Shepherd <darren@rancher.com>
+Dave Trombley <dave.trombley@gmail.com>
+Dave Tucker <dt@docker.com>
+David Lawrence <david.lawrence@docker.com>
+David Verhasselt <david@crowdway.com>
+David Xia <dxia@spotify.com>
+davidli <wenquan.li@hp.com>
+Dejan Golja <dejan@golja.org>
+Derek McGowan <derek@mcgstyle.net>
+Diogo Mónica <diogo.monica@gmail.com>
+DJ Enriquez <dj.enriquez@infospace.com>
+Donald Huang <don.hcd@gmail.com>
+Doug Davis <dug@us.ibm.com>
+Eric Yang <windfarer@gmail.com>
+Fabio Huser <fabio@fh1.ch>
+farmerworking <farmerworking@gmail.com>
+Felix Yan <felixonmars@archlinux.org>
+Florentin Raud <florentin.raud@gmail.com>
+Frederick F. Kautz IV <fkautz@alumni.cmu.edu>
+gabriell nascimento <gabriell@bluesoft.com.br>
+Gleb Schukin <gschukin@ptsecurity.com>
+harche <p.harshal@gmail.com>
+Henri Gomez <henri.gomez@gmail.com>
+Hu Keping <hukeping@huawei.com>
+Hua Wang <wanghua.humble@gmail.com>
+HuKeping <hukeping@huawei.com>
+Ian Babrou <ibobrik@gmail.com>
+igayoso <igayoso@gmail.com>
+Jack Griffin <jackpg14@gmail.com>
+Jason Freidman <jason.freidman@gmail.com>
+Jeff Nickoloff <jeff@allingeek.com>
+Jessie Frazelle <jessie@docker.com>
+jhaohai <jhaohai@foxmail.com>
+Jianqing Wang <tsing@jianqing.org>
+John Starks <jostarks@microsoft.com>
+Jon Johnson <jonjohnson@google.com>
+Jon Poler <jonathan.poler@apcera.com>
+Jonathan Boulle <jonathanboulle@gmail.com>
+Jordan Liggitt <jliggitt@redhat.com>
+Josh Hawn <josh.hawn@docker.com>
+Julien Fernandez <julien.fernandez@gmail.com>
+Ke Xu <leonhartx.k@gmail.com>
+Keerthan Mala <kmala@engineyard.com>
+Kelsey Hightower <kelsey.hightower@gmail.com>
+Kenneth Lim <kennethlimcp@gmail.com>
+Kenny Leung <kleung@google.com>
+Li Yi <denverdino@gmail.com>
+Liu Hua <sdu.liu@huawei.com>
+liuchang0812 <liuchang0812@gmail.com>
+Louis Kottmann <louis.kottmann@gmail.com>
+Luke Carpenter <x@rubynerd.net>
+Mary Anthony <mary@docker.com>
+Matt Bentley <mbentley@mbentley.net>
+Matt Duch <matt@learnmetrics.com>
+Matt Moore <mattmoor@google.com>
+Matt Robenolt <matt@ydekproductions.com>
+Michael Prokop <mika@grml.org>
+Michal Minar <miminar@redhat.com>
+Miquel Sabaté <msabate@suse.com>
+Morgan Bauer <mbauer@us.ibm.com>
+moxiegirl <mary@docker.com>
+Nathan Sullivan <nathan@nightsys.net>
+nevermosby <robolwq@qq.com>
+Nghia Tran <tcnghia@gmail.com>
+Nikita Tarasov <nikita@mygento.ru>
+Nuutti Kotivuori <nuutti.kotivuori@poplatek.fi>
+Oilbeater <liumengxinfly@gmail.com>
+Olivier Gambier <olivier@docker.com>
+Olivier Jacques <olivier.jacques@hp.com>
+Omer Cohen <git@omer.io>
+Patrick Devine <patrick.devine@docker.com>
+Phil Estes <estesp@linux.vnet.ibm.com>
+Philip Misiowiec <philip@atlashealth.com>
+Richard Scothern <richard.scothern@docker.com>
+Rodolfo Carvalho <rhcarvalho@gmail.com>
+Rusty Conover <rusty@luckydinosaur.com>
+Sean Boran <Boran@users.noreply.github.com>
+Sebastiaan van Stijn <github@gone.nl>
+Serge Dubrouski <sergeyfd@gmail.com>
+Sharif Nassar <sharif@mrwacky.com>
+Shawn Falkner-Horine <dreadpirateshawn@gmail.com>
+Shreyas Karnik <karnik.shreyas@gmail.com>
+Simon Thulbourn <simon+github@thulbourn.com>
+Spencer Rinehart <anubis@overthemonkey.com>
+Stefan Majewsky <stefan.majewsky@sap.com>
+Stefan Weil <sw@weilnetz.de>
+Stephen J Day <stephen.day@docker.com>
+Sungho Moon <sungho.moon@navercorp.com>
+Sven Dowideit <SvenDowideit@home.org.au>
+Sylvain Baubeau <sbaubeau@redhat.com>
+Ted Reed <ted.reed@gmail.com>
+tgic <farmer1992@gmail.com>
+Thomas Sjögren <konstruktoid@users.noreply.github.com>
+Tianon Gravi <admwiggin@gmail.com>
+Tibor Vass <teabee89@gmail.com>
+Tonis Tiigi <tonistiigi@gmail.com>
+Tony Holdstock-Brown <tony@docker.com>
+Trevor Pounds <trevor.pounds@gmail.com>
+Troels Thomsen <troels@thomsen.io>
+Vincent Batts <vbatts@redhat.com>
+Vincent Demeester <vincent@sbr.pm>
+Vincent Giersch <vincent.giersch@ovh.net>
+W. Trevor King <wking@tremily.us>
+weiyuan.yl <weiyuan.yl@alibaba-inc.com>
+xg.song <xg.song@venusource.com>
+xiekeyang <xiekeyang@huawei.com>
+Yann ROBERT <yann.robert@anantaplex.fr>
+yuzou <zouyu7@huawei.com>
+zhouhaibing089 <zhouhaibing089@gmail.com>
+姜继忠 <jizhong.jiangjz@alibaba-inc.com>

vendor/github.com/docker/distribution/BUILDING.md

@@ -0,0 +1,119 @@
+
+# Building the registry source
+
+## Use-case
+
+This is useful if you intend to actively work on the registry.
+
+### Alternatives
+
+Most people should use the [official Registry docker image](https://hub.docker.com/r/library/registry/).
+
+People looking for advanced operational use cases might consider rolling their own image with a custom Dockerfile inheriting `FROM registry:2`.
+
+OS X users who want to run natively can do so following [the instructions here](osx-setup-guide.md).
+
+### Gotchas
+
+You are expected to know your way around with go & git.
+
+If you are a casual user with no development experience, and no preliminary knowledge of go, building from source is probably not a good solution for you.
+
+## Build the development environment
+
+The first prerequisite of properly building distribution targets is to have a Go
+development environment setup. Please follow [How to Write Go Code](https://golang.org/doc/code.html)
+for proper setup. If done correctly, you should have a GOROOT and GOPATH set in the
+environment.
+
+If a Go development environment is setup, one can use `go get` to install the
+`registry` command from the current latest:
+
+    go get github.com/docker/distribution/cmd/registry
+
+The above will install the source repository into the `GOPATH`.
+
+Now create the directory for the registry data (this might require you to set permissions properly)
+
+    mkdir -p /var/lib/registry
+
+... or alternatively `export REGISTRY_STORAGE_FILESYSTEM_ROOTDIRECTORY=/somewhere` if you want to store data into another location.
+
+The `registry`
+binary can then be run with the following:
+
+    $ $GOPATH/bin/registry --version
+    $GOPATH/bin/registry github.com/docker/distribution v2.0.0-alpha.1+unknown
+
+> __NOTE:__ While you do not need to use `go get` to checkout the distribution
+> project, for these build instructions to work, the project must be checked
+> out in the correct location in the `GOPATH`. This should almost always be
+> `$GOPATH/src/github.com/docker/distribution`.
+
+The registry can be run with the default config using the following
+incantation:
+
+    $ $GOPATH/bin/registry serve $GOPATH/src/github.com/docker/distribution/cmd/registry/config-example.yml
+    INFO[0000] endpoint local-5003 disabled, skipping        app.id=34bbec38-a91a-494a-9a3f-b72f9010081f version=v2.0.0-alpha.1+unknown
+    INFO[0000] endpoint local-8083 disabled, skipping        app.id=34bbec38-a91a-494a-9a3f-b72f9010081f version=v2.0.0-alpha.1+unknown
+    INFO[0000] listening on :5000                            app.id=34bbec38-a91a-494a-9a3f-b72f9010081f version=v2.0.0-alpha.1+unknown
+    INFO[0000] debug server listening localhost:5001
+
+If it is working, one should see the above log messages.
+
+### Repeatable Builds
+
+For the full development experience, one should `cd` into
+`$GOPATH/src/github.com/docker/distribution`. From there, the regular `go`
+commands, such as `go test`, should work per package (please see
+[Developing](#developing) if they don't work).
+
+A `Makefile` has been provided as a convenience to support repeatable builds.
+Please install the following into `GOPATH` for it to work:
+
+    go get github.com/tools/godep github.com/golang/lint/golint
+
+**TODO(stevvooe):** Add a `make setup` command to Makefile to run this. Have to think about how to interact with Godeps properly.
+
+Once these commands are available in the `GOPATH`, run `make` to get a full
+build:
+
+    $ make
+    + clean
+    + fmt
+    + vet
+    + lint
+    + build
+    github.com/docker/docker/vendor/src/code.google.com/p/go/src/pkg/archive/tar
+    github.com/Sirupsen/logrus
+    github.com/docker/libtrust
+    ...
+    github.com/yvasiyarov/gorelic
+    github.com/docker/distribution/registry/handlers
+    github.com/docker/distribution/cmd/registry
+    + test
+    ...
+    ok    github.com/docker/distribution/digest 7.875s
+    ok    github.com/docker/distribution/manifest 0.028s
+    ok    github.com/docker/distribution/notifications  17.322s
+    ?     github.com/docker/distribution/registry [no test files]
+    ok    github.com/docker/distribution/registry/api/v2  0.101s
+    ?     github.com/docker/distribution/registry/auth  [no test files]
+    ok    github.com/docker/distribution/registry/auth/silly  0.011s
+    ...
+    + /Users/sday/go/src/github.com/docker/distribution/bin/registry
+    + /Users/sday/go/src/github.com/docker/distribution/bin/registry-api-descriptor-template
+    + binaries
+
+The above provides a repeatable build using the contents of the vendored
+Godeps directory. This includes formatting, vetting, linting, building,
+testing and generating tagged binaries. We can verify this worked by running
+the registry binary generated in the "./bin" directory:
+
+    $ ./bin/registry -version
+    ./bin/registry github.com/docker/distribution v2.0.0-alpha.2-80-g16d8b2c.m
+
+### Optional build tags
+
+Optional [build tags](http://golang.org/pkg/go/build/) can be provided using
+the environment variable `DOCKER_BUILDTAGS`.

vendor/github.com/docker/distribution/CHANGELOG.md

@@ -0,0 +1,35 @@
+# Changelog
+
+## 2.5.0 (2016-06-14)
+
+### Storage
+- Ensure uploads directory is cleaned after upload is commited
+- Add ability to cap concurrent operations in filesystem driver
+- S3: Add 'us-gov-west-1' to the valid region list
+- Swift: Handle ceph not returning Last-Modified header for HEAD requests
+- Add redirect middleware
+
+#### Registry
+- Add support for blobAccessController middleware
+- Add support for layers from foreign sources
+- Remove signature store
+- Add support for Let's Encrypt
+- Correct yaml key names in configuration
+
+#### Client
+- Add option to get content digest from manifest get
+
+#### Spec
+- Update the auth spec scope grammar to reflect the fact that hostnames are optionally supported
+- Clarify API documentation around catalog fetch behavior
+
+### API
+- Support returning HTTP 429 (Too Many Requests)
+
+### Documentation
+- Update auth documentation examples to show "expires in" as int
+
+### Docker Image
+- Use Alpine Linux as base image
+
+

vendor/github.com/docker/distribution/CONTRIBUTING.md

@@ -0,0 +1,140 @@
+# Contributing to the registry
+
+## Before reporting an issue...
+
+### If your problem is with...
+
+ - automated builds
+ - your account on the [Docker Hub](https://hub.docker.com/)
+ - any other [Docker Hub](https://hub.docker.com/) issue
+
+Then please do not report your issue here - you should instead report it to [https://support.docker.com](https://support.docker.com)
+
+### If you...
+
+ - need help setting up your registry
+ - can't figure out something
+ - are not sure what's going on or what your problem is
+
+Then please do not open an issue here yet - you should first try one of the following support forums:
+
+ - irc: #docker-distribution on freenode
+ - mailing-list: <distribution@dockerproject.org> or https://groups.google.com/a/dockerproject.org/forum/#!forum/distribution
+
+## Reporting an issue properly
+
+By following these simple rules you will get better and faster feedback on your issue.
+
+ - search the bugtracker for an already reported issue
+
+### If you found an issue that describes your problem:
+
+ - please read other user comments first, and confirm this is the same issue: a given error condition might be indicative of different problems - you may also find a workaround in the comments
+ - please refrain from adding "same thing here" or "+1" comments
+ - you don't need to comment on an issue to get notified of updates: just hit the "subscribe" button
+ - comment if you have some new, technical and relevant information to add to the case
+ - __DO NOT__ comment on closed issues or merged PRs. If you think you have a related problem, open up a new issue and reference the PR or issue.
+
+### If you have not found an existing issue that describes your problem:
+
+ 1. create a new issue, with a succinct title that describes your issue:
+   - bad title: "It doesn't work with my docker"
+   - good title: "Private registry push fail: 400 error with E_INVALID_DIGEST"
+ 2. copy the output of:
+   - `docker version`
+   - `docker info`
+   - `docker exec <registry-container> registry -version`
+ 3. copy the command line you used to launch your Registry
+ 4. restart your docker daemon in debug mode (add `-D` to the daemon launch arguments)
+ 5. reproduce your problem and get your docker daemon logs showing the error
+ 6. if relevant, copy your registry logs that show the error
+ 7. provide any relevant detail about your specific Registry configuration (e.g., storage backend used)
+ 8. indicate if you are using an enterprise proxy, Nginx, or anything else between you and your Registry
+
+## Contributing a patch for a known bug, or a small correction
+
+You should follow the basic GitHub workflow:
+
+ 1. fork
+ 2. commit a change
+ 3. make sure the tests pass
+ 4. PR
+
+Additionally, you must [sign your commits](https://github.com/docker/docker/blob/master/CONTRIBUTING.md#sign-your-work). It's very simple:
+
+ - configure your name with git: `git config user.name "Real Name" && git config user.email mail@example.com`
+ - sign your commits using `-s`: `git commit -s -m "My commit"`
+
+Some simple rules to ensure quick merge:
+
+ - clearly point to the issue(s) you want to fix in your PR comment (e.g., `closes #12345`)
+ - prefer multiple (smaller) PRs addressing individual issues over a big one trying to address multiple issues at once
+ - if you need to amend your PR following comments, please squash instead of adding more commits
+
+## Contributing new features
+
+You are heavily encouraged to first discuss what you want to do. You can do so on the irc channel, or by opening an issue that clearly describes the use case you want to fulfill, or the problem you are trying to solve.
+
+If this is a major new feature, you should then submit a proposal that describes your technical solution and reasoning.
+If you did discuss it first, this will likely be greenlighted very fast. It's advisable to address all feedback on this proposal before starting actual work.
+
+Then you should submit your implementation, clearly linking to the issue (and possible proposal).
+
+Your PR will be reviewed by the community, then ultimately by the project maintainers, before being merged.
+
+It's mandatory to:
+
+ - interact respectfully with other community members and maintainers - more generally, you are expected to abide by the [Docker community rules](https://github.com/docker/docker/blob/master/CONTRIBUTING.md#docker-community-guidelines)
+ - address maintainers' comments and modify your submission accordingly
+ - write tests for any new code
+
+Complying to these simple rules will greatly accelerate the review process, and will ensure you have a pleasant experience in contributing code to the Registry.
+
+Have a look at a great, successful contribution: the [Swift driver PR](https://github.com/docker/distribution/pull/493)
+
+## Coding Style
+
+Unless explicitly stated, we follow all coding guidelines from the Go
+community. While some of these standards may seem arbitrary, they somehow seem
+to result in a solid, consistent codebase.
+
+It is possible that the code base does not currently comply with these
+guidelines. We are not looking for a massive PR that fixes this, since that
+goes against the spirit of the guidelines. All new contributions should make a
+best effort to clean up and make the code base better than they left it.
+Obviously, apply your best judgement. Remember, the goal here is to make the
+code base easier for humans to navigate and understand. Always keep that in
+mind when nudging others to comply.
+
+The rules:
+
+1. All code should be formatted with `gofmt -s`.
+2. All code should pass the default levels of
+   [`golint`](https://github.com/golang/lint).
+3. All code should follow the guidelines covered in [Effective
+   Go](http://golang.org/doc/effective_go.html) and [Go Code Review
+   Comments](https://github.com/golang/go/wiki/CodeReviewComments).
+4. Comment the code. Tell us the why, the history and the context.
+5. Document _all_ declarations and methods, even private ones. Declare
+   expectations, caveats and anything else that may be important. If a type
+   gets exported, having the comments already there will ensure it's ready.
+6. Variable name length should be proportional to its context and no longer.
+   `noCommaALongVariableNameLikeThisIsNotMoreClearWhenASimpleCommentWouldDo`.
+   In practice, short methods will have short variable names and globals will
+   have longer names.
+7. No underscores in package names. If you need a compound name, step back,
+   and re-examine why you need a compound name. If you still think you need a
+   compound name, lose the underscore.
+8. No utils or helpers packages. If a function is not general enough to
+   warrant its own package, it has not been written generally enough to be a
+   part of a util package. Just leave it unexported and well-documented.
+9. All tests should run with `go test` and outside tooling should not be
+   required. No, we don't need another unit testing framework. Assertion
+   packages are acceptable if they provide _real_ incremental value.
+10. Even though we call these "rules" above, they are actually just
+    guidelines. Since you've read all the rules, you now know that.
+
+If you are having trouble getting into the mood of idiomatic Go, we recommend
+reading through [Effective Go](http://golang.org/doc/effective_go.html). The
+[Go Blog](http://blog.golang.org/) is also a great resource. Drinking the
+kool-aid is a lot easier than going thirsty.

vendor/github.com/docker/distribution/Dockerfile

@@ -0,0 +1,18 @@
+FROM golang:1.6-alpine
+
+ENV DISTRIBUTION_DIR /go/src/github.com/docker/distribution
+ENV DOCKER_BUILDTAGS include_oss include_gcs
+
+WORKDIR $DISTRIBUTION_DIR
+COPY . $DISTRIBUTION_DIR
+COPY cmd/registry/config-dev.yml /etc/docker/registry/config.yml
+
+RUN set -ex \
+    && apk add --no-cache make git
+
+RUN make PREFIX=/go clean binaries
+
+VOLUME ["/var/lib/registry"]
+EXPOSE 5000
+ENTRYPOINT ["registry"]
+CMD ["serve", "/etc/docker/registry/config.yml"]

vendor/github.com/docker/distribution/LICENSE

@@ -0,0 +1,202 @@
+Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
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vendor/github.com/docker/distribution/MAINTAINERS

@@ -0,0 +1,58 @@
+# Distribution maintainers file
+#
+# This file describes who runs the docker/distribution project and how.
+# This is a living document - if you see something out of date or missing, speak up!
+#
+# It is structured to be consumable by both humans and programs.
+# To extract its contents programmatically, use any TOML-compliant parser.
+#
+# This file is compiled into the MAINTAINERS file in docker/opensource.
+#
+[Org]
+	[Org."Core maintainers"]
+		people = [
+			"aaronlehmann",
+			"dmcgowan",
+			"dmp42",
+			"richardscothern",
+			"shykes",
+			"stevvooe",
+		]
+
+[people]
+
+# A reference list of all people associated with the project.
+# All other sections should refer to people by their canonical key
+# in the people section.
+
+	# ADD YOURSELF HERE IN ALPHABETICAL ORDER
+
+	[people.aaronlehmann]
+	Name = "Aaron Lehmann"
+	Email = "aaron.lehmann@docker.com"
+	GitHub = "aaronlehmann"
+
+	[people.dmcgowan]
+	Name = "Derek McGowan"
+	Email = "derek@mcgstyle.net"
+	GitHub = "dmcgowan"
+
+	[people.dmp42]
+	Name = "Olivier Gambier"
+	Email = "olivier@docker.com"
+	GitHub = "dmp42"
+
+	[people.richardscothern]
+	Name = "Richard Scothern"
+	Email = "richard.scothern@gmail.com"
+	GitHub = "richardscothern"
+
+	[people.shykes]
+	Name = "Solomon Hykes"
+	Email = "solomon@docker.com"
+	GitHub = "shykes"
+
+	[people.stevvooe]
+	Name = "Stephen Day"
+	Email = "stephen.day@docker.com"
+	GitHub = "stevvooe"

vendor/github.com/docker/distribution/Makefile

@@ -0,0 +1,106 @@
+# Set an output prefix, which is the local directory if not specified
+PREFIX?=$(shell pwd)
+
+
+# Used to populate version variable in main package.
+VERSION=$(shell git describe --match 'v[0-9]*' --dirty='.m' --always)
+
+# Allow turning off function inlining and variable registerization
+ifeq (${DISABLE_OPTIMIZATION},true)
+	GO_GCFLAGS=-gcflags "-N -l"
+	VERSION:="$(VERSION)-noopt"
+endif
+
+GO_LDFLAGS=-ldflags "-X `go list ./version`.Version=$(VERSION)"
+
+.PHONY: clean all fmt vet lint build test binaries
+.DEFAULT: all
+all: fmt vet lint build test binaries
+
+AUTHORS: .mailmap .git/HEAD
+	 git log --format='%aN <%aE>' | sort -fu > $@
+
+# This only needs to be generated by hand when cutting full releases.
+version/version.go:
+	./version/version.sh > $@
+
+# Required for go 1.5 to build
+GO15VENDOREXPERIMENT := 1
+
+# Package list
+PKGS := $(shell go list -tags "${DOCKER_BUILDTAGS}" ./... | grep -v ^github.com/docker/distribution/vendor/)
+
+# Resolving binary dependencies for specific targets
+GOLINT := $(shell which golint || echo '')
+GODEP := $(shell which godep || echo '')
+
+${PREFIX}/bin/registry: $(wildcard **/*.go)
+	@echo "+ $@"
+	@go build -tags "${DOCKER_BUILDTAGS}" -o $@ ${GO_LDFLAGS}  ${GO_GCFLAGS} ./cmd/registry
+
+${PREFIX}/bin/digest:  $(wildcard **/*.go)
+	@echo "+ $@"
+	@go build -tags "${DOCKER_BUILDTAGS}" -o $@ ${GO_LDFLAGS}  ${GO_GCFLAGS} ./cmd/digest
+
+${PREFIX}/bin/registry-api-descriptor-template: $(wildcard **/*.go)
+	@echo "+ $@"
+	@go build -o $@ ${GO_LDFLAGS} ${GO_GCFLAGS} ./cmd/registry-api-descriptor-template
+
+docs/spec/api.md: docs/spec/api.md.tmpl ${PREFIX}/bin/registry-api-descriptor-template
+	./bin/registry-api-descriptor-template $< > $@
+
+vet:
+	@echo "+ $@"
+	@go vet -tags "${DOCKER_BUILDTAGS}" $(PKGS)
+
+fmt:
+	@echo "+ $@"
+	@test -z "$$(gofmt -s -l . 2>&1 | grep -v ^vendor/ | tee /dev/stderr)" || \
+		(echo >&2 "+ please format Go code with 'gofmt -s'" && false)
+
+lint:
+	@echo "+ $@"
+	$(if $(GOLINT), , \
+		$(error Please install golint: `go get -u github.com/golang/lint/golint`))
+	@test -z "$$($(GOLINT) ./... 2>&1 | grep -v ^vendor/ | tee /dev/stderr)"
+
+build:
+	@echo "+ $@"
+	@go build -tags "${DOCKER_BUILDTAGS}" -v ${GO_LDFLAGS} $(PKGS)
+
+test:
+	@echo "+ $@"
+	@go test -test.short -tags "${DOCKER_BUILDTAGS}" $(PKGS)
+
+test-full:
+	@echo "+ $@"
+	@go test -tags "${DOCKER_BUILDTAGS}" $(PKGS)
+
+binaries: ${PREFIX}/bin/registry ${PREFIX}/bin/digest ${PREFIX}/bin/registry-api-descriptor-template
+	@echo "+ $@"
+
+clean:
+	@echo "+ $@"
+	@rm -rf "${PREFIX}/bin/registry" "${PREFIX}/bin/digest" "${PREFIX}/bin/registry-api-descriptor-template"
+
+dep-save:
+	@echo "+ $@"
+	$(if $(GODEP), , \
+		$(error Please install godep: go get github.com/tools/godep))
+	@$(GODEP) save $(PKGS)
+
+dep-restore:
+	@echo "+ $@"
+	$(if $(GODEP), , \
+		$(error Please install godep: go get github.com/tools/godep))
+	@$(GODEP) restore -v
+
+dep-validate: dep-restore
+	@echo "+ $@"
+	@rm -Rf .vendor.bak
+	@mv vendor .vendor.bak
+	@rm -Rf Godeps
+	@$(GODEP) save ./...
+	@test -z "$$(diff -r vendor .vendor.bak 2>&1 | tee /dev/stderr)" || \
+		(echo >&2 "+ borked dependencies! what you have in Godeps/Godeps.json does not match with what you have in vendor" && false)
+	@rm -Rf .vendor.bak

vendor/github.com/docker/distribution/README.md

@@ -0,0 +1,131 @@
+# Distribution
+
+The Docker toolset to pack, ship, store, and deliver content.
+
+This repository's main product is the Docker Registry 2.0 implementation
+for storing and distributing Docker images. It supersedes the
+[docker/docker-registry](https://github.com/docker/docker-registry)
+project with a new API design, focused around security and performance.
+
+<img src="https://www.docker.com/sites/default/files/oyster-registry-3.png" width=200px/>
+
+[![Circle CI](https://circleci.com/gh/docker/distribution/tree/master.svg?style=svg)](https://circleci.com/gh/docker/distribution/tree/master)
+[![GoDoc](https://godoc.org/github.com/docker/distribution?status.svg)](https://godoc.org/github.com/docker/distribution)
+
+This repository contains the following components:
+
+|**Component**       |Description                                                                                                                                                                                         |
+|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| **registry**       | An implementation of the [Docker Registry HTTP API V2](docs/spec/api.md) for use with docker 1.6+.                                                                                                  |
+| **libraries**      | A rich set of libraries for interacting with distribution components. Please see [godoc](https://godoc.org/github.com/docker/distribution) for details. **Note**: These libraries are **unstable**. |
+| **specifications** | _Distribution_ related specifications are available in [docs/spec](docs/spec)                                                                                                                        |
+| **documentation**  | Docker's full documentation set is available at [docs.docker.com](https://docs.docker.com). This repository [contains the subset](docs/index.md) related just to the registry.                                                                                                                                          |
+
+### How does this integrate with Docker engine?
+
+This project should provide an implementation to a V2 API for use in the [Docker
+core project](https://github.com/docker/docker). The API should be embeddable
+and simplify the process of securely pulling and pushing content from `docker`
+daemons.
+
+### What are the long term goals of the Distribution project?
+
+The _Distribution_ project has the further long term goal of providing a
+secure tool chain for distributing content. The specifications, APIs and tools
+should be as useful with Docker as they are without.
+
+Our goal is to design a professional grade and extensible content distribution
+system that allow users to:
+
+* Enjoy an efficient, secured and reliable way to store, manage, package and
+  exchange content
+* Hack/roll their own on top of healthy open-source components
+* Implement their own home made solution through good specs, and solid
+  extensions mechanism.
+
+## More about Registry 2.0
+
+The new registry implementation provides the following benefits:
+
+- faster push and pull
+- new, more efficient implementation
+- simplified deployment
+- pluggable storage backend
+- webhook notifications
+
+For information on upcoming functionality, please see [ROADMAP.md](ROADMAP.md).
+
+### Who needs to deploy a registry?
+
+By default, Docker users pull images from Docker's public registry instance.
+[Installing Docker](https://docs.docker.com/engine/installation/) gives users this
+ability. Users can also push images to a repository on Docker's public registry,
+if they have a [Docker Hub](https://hub.docker.com/) account. 
+
+For some users and even companies, this default behavior is sufficient. For
+others, it is not. 
+
+For example, users with their own software products may want to maintain a
+registry for private, company images. Also, you may wish to deploy your own
+image repository for images used to test or in continuous integration. For these
+use cases and others, [deploying your own registry instance](docs/deploying.md)
+may be the better choice.
+
+### Migration to Registry 2.0
+
+For those who have previously deployed their own registry based on the Registry
+1.0 implementation and wish to deploy a Registry 2.0 while retaining images,
+data migration is required. A tool to assist with migration efforts has been
+created. For more information see [docker/migrator]
+(https://github.com/docker/migrator).
+
+## Contribute
+
+Please see [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to contribute
+issues, fixes, and patches to this project. If you are contributing code, see
+the instructions for [building a development environment](docs/recipes/building.md).
+
+## Support
+
+If any issues are encountered while using the _Distribution_ project, several
+avenues are available for support:
+
+<table>
+<tr>
+	<th align="left">
+	IRC
+	</th>
+	<td>
+	#docker-distribution on FreeNode
+	</td>
+</tr>
+<tr>
+	<th align="left">
+	Issue Tracker
+	</th>
+	<td>
+	github.com/docker/distribution/issues
+	</td>
+</tr>
+<tr>
+	<th align="left">
+	Google Groups
+	</th>
+	<td>
+	https://groups.google.com/a/dockerproject.org/forum/#!forum/distribution
+	</td>
+</tr>
+<tr>
+	<th align="left">
+	Mailing List
+	</th>
+	<td>
+	docker@dockerproject.org
+	</td>
+</tr>
+</table>
+
+
+## License
+
+This project is distributed under [Apache License, Version 2.0](LICENSE).

vendor/github.com/docker/distribution/ROADMAP.md

@@ -0,0 +1,267 @@
+# Roadmap
+
+The Distribution Project consists of several components, some of which are
+still being defined. This document defines the high-level goals of the
+project, identifies the current components, and defines the release-
+relationship to the Docker Platform.
+
+* [Distribution Goals](#distribution-goals)
+* [Distribution Components](#distribution-components)
+* [Project Planning](#project-planning): release-relationship to the Docker Platform.
+
+This road map is a living document, providing an overview of the goals and
+considerations made in respect of the future of the project.
+
+## Distribution Goals
+
+- Replace the existing [docker registry](github.com/docker/docker-registry)
+  implementation as the primary implementation.
+- Replace the existing push and pull code in the docker engine with the
+  distribution package.
+- Define a strong data model for distributing docker images
+- Provide a flexible distribution tool kit for use in the docker platform
+- Unlock new distribution models
+
+## Distribution Components
+
+Components of the Distribution Project are managed via github [milestones](https://github.com/docker/distribution/milestones). Upcoming
+features and bugfixes for a component will be added to the relevant milestone. If a feature or
+bugfix is not part of a milestone, it is currently unscheduled for
+implementation. 
+
+* [Registry](#registry)
+* [Distribution Package](#distribution-package)
+
+***
+
+### Registry
+
+The new Docker registry is the main portion of the distribution repository.
+Registry 2.0 is the first release of the next-generation registry. This was
+primarily focused on implementing the [new registry
+API](https://github.com/docker/distribution/blob/master/docs/spec/api.md),
+with a focus on security and performance. 
+
+Following from the Distribution project goals above, we have a set of goals
+for registry v2 that we would like to follow in the design. New features
+should be compared against these goals.
+
+#### Data Storage and Distribution First
+
+The registry's first goal is to provide a reliable, consistent storage
+location for Docker images. The registry should only provide the minimal
+amount of indexing required to fetch image data and no more.
+
+This means we should be selective in new features and API additions, including
+those that may require expensive, ever growing indexes. Requests should be
+servable in "constant time".
+
+#### Content Addressability
+
+All data objects used in the registry API should be content addressable.
+Content identifiers should be secure and verifiable. This provides a secure,
+reliable base from which to build more advanced content distribution systems.
+
+#### Content Agnostic
+
+In the past, changes to the image format would require large changes in Docker
+and the Registry. By decoupling the distribution and image format, we can
+allow the formats to progress without having to coordinate between the two.
+This means that we should be focused on decoupling Docker from the registry
+just as much as decoupling the registry from Docker. Such an approach will
+allow us to unlock new distribution models that haven't been possible before.
+
+We can take this further by saying that the new registry should be content
+agnostic. The registry provides a model of names, tags, manifests and content
+addresses and that model can be used to work with content.
+
+#### Simplicity
+
+The new registry should be closer to a microservice component than its
+predecessor. This means it should have a narrower API and a low number of
+service dependencies. It should be easy to deploy.
+
+This means that other solutions should be explored before changing the API or
+adding extra dependencies. If functionality is required, can it be added as an
+extension or companion service.
+
+#### Extensibility
+
+The registry should provide extension points to add functionality. By keeping
+the scope narrow, but providing the ability to add functionality.
+
+Features like search, indexing, synchronization and registry explorers fall
+into this category. No such feature should be added unless we've found it
+impossible to do through an extension.
+
+#### Active Feature Discussions
+
+The following are feature discussions that are currently active.
+
+If you don't see your favorite, unimplemented feature, feel free to contact us
+via IRC or the mailing list and we can talk about adding it. The goal here is
+to make sure that new features go through a rigid design process before
+landing in the registry.
+
+##### Proxying to other Registries
+
+A _pull-through caching_ mode exists for the registry, but is restricted from 
+within the docker client to only mirror the official Docker Hub.  This functionality
+can be expanded when image provenance has been specified and implemented in the 
+distribution project.
+
+##### Metadata storage
+
+Metadata for the registry is currently stored with the manifest and layer data on
+the storage backend.  While this is a big win for simplicity and reliably maintaining
+state, it comes with the cost of consistency and high latency.  The mutable registry
+metadata operations should be abstracted behind an API which will allow ACID compliant
+storage systems to handle metadata.
+
+##### Peer to Peer transfer
+
+Discussion has started here: https://docs.google.com/document/d/1rYDpSpJiQWmCQy8Cuiaa3NH-Co33oK_SC9HeXYo87QA/edit
+
+##### Indexing, Search and Discovery
+
+The original registry provided some implementation of search for use with
+private registries. Support has been elided from V2 since we'd like to both
+decouple search functionality from the registry. The makes the registry
+simpler to deploy, especially in use cases where search is not needed, and
+let's us decouple the image format from the registry.
+
+There are explorations into using the catalog API and notification system to
+build external indexes. The current line of thought is that we will define a
+common search API to index and query docker images. Such a system could be run
+as a companion to a registry or set of registries to power discovery.
+
+The main issue with search and discovery is that there are so many ways to
+accomplish it. There are two aspects to this project. The first is deciding on
+how it will be done, including an API definition that can work with changing
+data formats. The second is the process of integrating with `docker search`.
+We expect that someone attempts to address the problem with the existing tools
+and propose it as a standard search API or uses it to inform a standardization
+process. Once this has been explored, we integrate with the docker client.
+
+Please see the following for more detail:
+
+- https://github.com/docker/distribution/issues/206
+
+##### Deletes
+
+> __NOTE:__ Deletes are a much asked for feature. Before requesting this
+feature or participating in discussion, we ask that you read this section in
+full and understand the problems behind deletes.
+
+While, at first glance, implementing deleting seems simple, there are a number
+mitigating factors that make many solutions not ideal or even pathological in
+the context of a registry. The following paragraph discuss the background and
+approaches that could be applied to arrive at a solution.
+
+The goal of deletes in any system is to remove unused or unneeded data. Only
+data requested for deletion should be removed and no other data. Removing
+unintended data is worse than _not_ removing data that was requested for
+removal but ideally, both are supported. Generally, according to this rule, we
+err on holding data longer than needed, ensuring that it is only removed when
+we can be certain that it can be removed. With the current behavior, we opt to
+hold onto the data forever, ensuring that data cannot be incorrectly removed.
+
+To understand the problems with implementing deletes, one must understand the
+data model. All registry data is stored in a filesystem layout, implemented on
+a "storage driver", effectively a _virtual file system_ (VFS). The storage
+system must assume that this VFS layer will be eventually consistent and has
+poor read- after-write consistency, since this is the lower common denominator
+among the storage drivers. This is mitigated by writing values in reverse-
+dependent order, but makes wider transactional operations unsafe.
+
+Layered on the VFS model is a content-addressable _directed, acyclic graph_
+(DAG) made up of blobs. Manifests reference layers. Tags reference manifests.
+Since the same data can be referenced by multiple manifests, we only store
+data once, even if it is in different repositories. Thus, we have a set of
+blobs, referenced by tags and manifests. If we want to delete a blob we need
+to be certain that it is no longer referenced by another manifest or tag. When
+we delete a manifest, we also can try to delete the referenced blobs. Deciding
+whether or not a blob has an active reference is the crux of the problem.
+
+Conceptually, deleting a manifest and its resources is quite simple. Just find
+all the manifests, enumerate the referenced blobs and delete the blobs not in
+that set. An astute observer will recognize this as a garbage collection
+problem. As with garbage collection in programming languages, this is very
+simple when one always has a consistent view. When one adds parallelism and an
+inconsistent view of data, it becomes very challenging.
+
+A simple example can demonstrate this. Let's say we are deleting a manifest
+_A_ in one process. We scan the manifest and decide that all the blobs are
+ready for deletion. Concurrently, we have another process accepting a new
+manifest _B_ referencing one or more blobs from the manifest _A_. Manifest _B_
+is accepted and all the blobs are considered present, so the operation
+proceeds. The original process then deletes the referenced blobs, assuming
+they were unreferenced. The manifest _B_, which we thought had all of its data
+present, can no longer be served by the registry, since the dependent data has
+been deleted.
+
+Deleting data from the registry safely requires some way to coordinate this
+operation. The following approaches are being considered:
+
+- _Reference Counting_ - Maintain a count of references to each blob. This is
+  challenging for a number of reasons: 1. maintaining a consistent consensus
+  of reference counts across a set of Registries and 2. Building the initial
+  list of reference counts for an existing registry. These challenges can be
+  met with a consensus protocol like Paxos or Raft in the first case and a
+  necessary but simple scan in the second..
+- _Lock the World GC_ - Halt all writes to the data store. Walk the data store
+  and find all blob references. Delete all unreferenced blobs. This approach
+  is very simple but requires disabling writes for a period of time while the
+  service reads all data. This is slow and expensive but very accurate and
+  effective.
+- _Generational GC_ - Do something similar to above but instead of blocking
+  writes, writes are sent to another storage backend while reads are broadcast
+  to the new and old backends. GC is then performed on the read-only portion.
+  Because writes land in the new backend, the data in the read-only section
+  can be safely deleted. The main drawbacks of this approach are complexity
+  and coordination.
+- _Centralized Oracle_ - Using a centralized, transactional database, we can
+  know exactly which data is referenced at any given time. This avoids
+  coordination problem by managing this data in a single location. We trade
+  off metadata scalability for simplicity and performance. This is a very good
+  option for most registry deployments. This would create a bottleneck for
+  registry metadata. However, metadata is generally not the main bottleneck
+  when serving images.
+
+Please let us know if other solutions exist that we have yet to enumerate.
+Note that for any approach, implementation is a massive consideration. For
+example, a mark-sweep based solution may seem simple but the amount of work in
+coordination offset the extra work it might take to build a _Centralized
+Oracle_. We'll accept proposals for any solution but please coordinate with us
+before dropping code.
+
+At this time, we have traded off simplicity and ease of deployment for disk
+space. Simplicity and ease of deployment tend to reduce developer involvement,
+which is currently the most expensive resource in software engineering. Taking
+on any solution for deletes will greatly effect these factors, trading off
+very cheap disk space for a complex deployment and operational story.
+
+Please see the following issues for more detail:
+
+- https://github.com/docker/distribution/issues/422
+- https://github.com/docker/distribution/issues/461
+- https://github.com/docker/distribution/issues/462
+
+### Distribution Package 
+
+At its core, the Distribution Project is a set of Go packages that make up
+Distribution Components. At this time, most of these packages make up the
+Registry implementation. 
+
+The package itself is considered unstable. If you're using it, please take care to vendor the dependent version. 
+
+For feature additions, please see the Registry section. In the future, we may break out a
+separate Roadmap for distribution-specific features that apply to more than
+just the registry.
+
+***
+
+### Project Planning
+
+An [Open-Source Planning Process](https://github.com/docker/distribution/wiki/Open-Source-Planning-Process) is used to define the Roadmap. [Project Pages](https://github.com/docker/distribution/wiki) define the goals for each Milestone and identify current progress.
+

vendor/github.com/docker/distribution/blobs.go

@@ -0,0 +1,245 @@
+package distribution
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/docker/distribution/context"
+	"github.com/docker/distribution/digest"
+	"github.com/docker/distribution/reference"
+)
+
+var (
+	// ErrBlobExists returned when blob already exists
+	ErrBlobExists = errors.New("blob exists")
+
+	// ErrBlobDigestUnsupported when blob digest is an unsupported version.
+	ErrBlobDigestUnsupported = errors.New("unsupported blob digest")
+
+	// ErrBlobUnknown when blob is not found.
+	ErrBlobUnknown = errors.New("unknown blob")
+
+	// ErrBlobUploadUnknown returned when upload is not found.
+	ErrBlobUploadUnknown = errors.New("blob upload unknown")
+
+	// ErrBlobInvalidLength returned when the blob has an expected length on
+	// commit, meaning mismatched with the descriptor or an invalid value.
+	ErrBlobInvalidLength = errors.New("blob invalid length")
+)
+
+// ErrBlobInvalidDigest returned when digest check fails.
+type ErrBlobInvalidDigest struct {
+	Digest digest.Digest
+	Reason error
+}
+
+func (err ErrBlobInvalidDigest) Error() string {
+	return fmt.Sprintf("invalid digest for referenced layer: %v, %v",
+		err.Digest, err.Reason)
+}
+
+// ErrBlobMounted returned when a blob is mounted from another repository
+// instead of initiating an upload session.
+type ErrBlobMounted struct {
+	From       reference.Canonical
+	Descriptor Descriptor
+}
+
+func (err ErrBlobMounted) Error() string {
+	return fmt.Sprintf("blob mounted from: %v to: %v",
+		err.From, err.Descriptor)
+}
+
+// Descriptor describes targeted content. Used in conjunction with a blob
+// store, a descriptor can be used to fetch, store and target any kind of
+// blob. The struct also describes the wire protocol format. Fields should
+// only be added but never changed.
+type Descriptor struct {
+	// MediaType describe the type of the content. All text based formats are
+	// encoded as utf-8.
+	MediaType string `json:"mediaType,omitempty"`
+
+	// Size in bytes of content.
+	Size int64 `json:"size,omitempty"`
+
+	// Digest uniquely identifies the content. A byte stream can be verified
+	// against against this digest.
+	Digest digest.Digest `json:"digest,omitempty"`
+
+	// URLs contains the source URLs of this content.
+	URLs []string `json:"urls,omitempty"`
+
+	// NOTE: Before adding a field here, please ensure that all
+	// other options have been exhausted. Much of the type relationships
+	// depend on the simplicity of this type.
+}
+
+// Descriptor returns the descriptor, to make it satisfy the Describable
+// interface. Note that implementations of Describable are generally objects
+// which can be described, not simply descriptors; this exception is in place
+// to make it more convenient to pass actual descriptors to functions that
+// expect Describable objects.
+func (d Descriptor) Descriptor() Descriptor {
+	return d
+}
+
+// BlobStatter makes blob descriptors available by digest. The service may
+// provide a descriptor of a different digest if the provided digest is not
+// canonical.
+type BlobStatter interface {
+	// Stat provides metadata about a blob identified by the digest. If the
+	// blob is unknown to the describer, ErrBlobUnknown will be returned.
+	Stat(ctx context.Context, dgst digest.Digest) (Descriptor, error)
+}
+
+// BlobDeleter enables deleting blobs from storage.
+type BlobDeleter interface {
+	Delete(ctx context.Context, dgst digest.Digest) error
+}
+
+// BlobEnumerator enables iterating over blobs from storage
+type BlobEnumerator interface {
+	Enumerate(ctx context.Context, ingester func(dgst digest.Digest) error) error
+}
+
+// BlobDescriptorService manages metadata about a blob by digest. Most
+// implementations will not expose such an interface explicitly. Such mappings
+// should be maintained by interacting with the BlobIngester. Hence, this is
+// left off of BlobService and BlobStore.
+type BlobDescriptorService interface {
+	BlobStatter
+
+	// SetDescriptor assigns the descriptor to the digest. The provided digest and
+	// the digest in the descriptor must map to identical content but they may
+	// differ on their algorithm. The descriptor must have the canonical
+	// digest of the content and the digest algorithm must match the
+	// annotators canonical algorithm.
+	//
+	// Such a facility can be used to map blobs between digest domains, with
+	// the restriction that the algorithm of the descriptor must match the
+	// canonical algorithm (ie sha256) of the annotator.
+	SetDescriptor(ctx context.Context, dgst digest.Digest, desc Descriptor) error
+
+	// Clear enables descriptors to be unlinked
+	Clear(ctx context.Context, dgst digest.Digest) error
+}
+
+// BlobDescriptorServiceFactory creates middleware for BlobDescriptorService.
+type BlobDescriptorServiceFactory interface {
+	BlobAccessController(svc BlobDescriptorService) BlobDescriptorService
+}
+
+// ReadSeekCloser is the primary reader type for blob data, combining
+// io.ReadSeeker with io.Closer.
+type ReadSeekCloser interface {
+	io.ReadSeeker
+	io.Closer
+}
+
+// BlobProvider describes operations for getting blob data.
+type BlobProvider interface {
+	// Get returns the entire blob identified by digest along with the descriptor.
+	Get(ctx context.Context, dgst digest.Digest) ([]byte, error)
+
+	// Open provides a ReadSeekCloser to the blob identified by the provided
+	// descriptor. If the blob is not known to the service, an error will be
+	// returned.
+	Open(ctx context.Context, dgst digest.Digest) (ReadSeekCloser, error)
+}
+
+// BlobServer can serve blobs via http.
+type BlobServer interface {
+	// ServeBlob attempts to serve the blob, identifed by dgst, via http. The
+	// service may decide to redirect the client elsewhere or serve the data
+	// directly.
+	//
+	// This handler only issues successful responses, such as 2xx or 3xx,
+	// meaning it serves data or issues a redirect. If the blob is not
+	// available, an error will be returned and the caller may still issue a
+	// response.
+	//
+	// The implementation may serve the same blob from a different digest
+	// domain. The appropriate headers will be set for the blob, unless they
+	// have already been set by the caller.
+	ServeBlob(ctx context.Context, w http.ResponseWriter, r *http.Request, dgst digest.Digest) error
+}
+
+// BlobIngester ingests blob data.
+type BlobIngester interface {
+	// Put inserts the content p into the blob service, returning a descriptor
+	// or an error.
+	Put(ctx context.Context, mediaType string, p []byte) (Descriptor, error)
+
+	// Create allocates a new blob writer to add a blob to this service. The
+	// returned handle can be written to and later resumed using an opaque
+	// identifier. With this approach, one can Close and Resume a BlobWriter
+	// multiple times until the BlobWriter is committed or cancelled.
+	Create(ctx context.Context, options ...BlobCreateOption) (BlobWriter, error)
+
+	// Resume attempts to resume a write to a blob, identified by an id.
+	Resume(ctx context.Context, id string) (BlobWriter, error)
+}
+
+// BlobCreateOption is a general extensible function argument for blob creation
+// methods. A BlobIngester may choose to honor any or none of the given
+// BlobCreateOptions, which can be specific to the implementation of the
+// BlobIngester receiving them.
+// TODO (brianbland): unify this with ManifestServiceOption in the future
+type BlobCreateOption interface {
+	Apply(interface{}) error
+}
+
+// BlobWriter provides a handle for inserting data into a blob store.
+// Instances should be obtained from BlobWriteService.Writer and
+// BlobWriteService.Resume. If supported by the store, a writer can be
+// recovered with the id.
+type BlobWriter interface {
+	io.WriteCloser
+	io.ReaderFrom
+
+	// Size returns the number of bytes written to this blob.
+	Size() int64
+
+	// ID returns the identifier for this writer. The ID can be used with the
+	// Blob service to later resume the write.
+	ID() string
+
+	// StartedAt returns the time this blob write was started.
+	StartedAt() time.Time
+
+	// Commit completes the blob writer process. The content is verified
+	// against the provided provisional descriptor, which may result in an
+	// error. Depending on the implementation, written data may be validated
+	// against the provisional descriptor fields. If MediaType is not present,
+	// the implementation may reject the commit or assign "application/octet-
+	// stream" to the blob. The returned descriptor may have a different
+	// digest depending on the blob store, referred to as the canonical
+	// descriptor.
+	Commit(ctx context.Context, provisional Descriptor) (canonical Descriptor, err error)
+
+	// Cancel ends the blob write without storing any data and frees any
+	// associated resources. Any data written thus far will be lost. Cancel
+	// implementations should allow multiple calls even after a commit that
+	// result in a no-op. This allows use of Cancel in a defer statement,
+	// increasing the assurance that it is correctly called.
+	Cancel(ctx context.Context) error
+}
+
+// BlobService combines the operations to access, read and write blobs. This
+// can be used to describe remote blob services.
+type BlobService interface {
+	BlobStatter
+	BlobProvider
+	BlobIngester
+}
+
+// BlobStore represent the entire suite of blob related operations. Such an
+// implementation can access, read, write, delete and serve blobs.
+type BlobStore interface {
+	BlobService
+	BlobServer
+	BlobDeleter
+}

vendor/github.com/docker/distribution/circle.yml

@@ -0,0 +1,89 @@
+# Pony-up!
+machine:
+  pre:
+  # Install gvm
+    - bash < <(curl -s -S -L https://raw.githubusercontent.com/moovweb/gvm/1.0.22/binscripts/gvm-installer)
+  # Install codecov for coverage
+    - pip install --user codecov
+
+  post:
+  # go
+    - gvm install go1.6 --prefer-binary --name=stable
+
+  environment:
+  # Convenient shortcuts to "common" locations
+    CHECKOUT: /home/ubuntu/$CIRCLE_PROJECT_REPONAME
+    BASE_DIR: src/github.com/$CIRCLE_PROJECT_USERNAME/$CIRCLE_PROJECT_REPONAME
+  # Trick circle brainflat "no absolute path" behavior
+    BASE_STABLE: ../../../$HOME/.gvm/pkgsets/stable/global/$BASE_DIR
+    DOCKER_BUILDTAGS: "include_oss include_gcs"
+  # Workaround Circle parsing dumb bugs and/or YAML wonkyness
+    CIRCLE_PAIN: "mode: set"
+
+  hosts:
+  # Not used yet
+    fancy: 127.0.0.1
+
+dependencies:
+  pre:
+  # Copy the code to the gopath of all go versions
+    - >
+      gvm use stable &&
+      mkdir -p "$(dirname $BASE_STABLE)" &&
+      cp -R "$CHECKOUT" "$BASE_STABLE"
+
+  override:
+  # Install dependencies for every copied clone/go version
+    - gvm use stable && go get github.com/tools/godep:
+        pwd: $BASE_STABLE
+
+  post:
+  # For the stable go version, additionally install linting tools
+    - >
+      gvm use stable &&
+      go get github.com/axw/gocov/gocov github.com/golang/lint/golint
+
+test:
+  pre:
+  # Output the go versions we are going to test
+    # - gvm use old && go version
+    - gvm use stable && go version
+
+  # Ensure validation of dependencies
+    - gvm use stable && if test -n "`git diff --stat=1000 master | grep -Ei \"vendor|godeps\"`"; then make dep-validate; fi:
+        pwd: $BASE_STABLE
+
+  # First thing: build everything. This will catch compile errors, and it's
+  # also necessary for go vet to work properly (see #807).
+    - gvm use stable && godep go install $(go list ./... | grep -v "/vendor/"):
+        pwd: $BASE_STABLE
+
+  # FMT
+    - gvm use stable && make fmt:
+        pwd: $BASE_STABLE
+
+   # VET
+    - gvm use stable && make vet:
+        pwd: $BASE_STABLE
+
+  # LINT
+    - gvm use stable && make lint:
+        pwd: $BASE_STABLE
+
+  override:
+  # Test stable, and report
+     - gvm use stable; export ROOT_PACKAGE=$(go list .); go list -tags "$DOCKER_BUILDTAGS" ./... | grep -v "/vendor/" | xargs -L 1 -I{} bash -c 'export PACKAGE={}; godep go test -tags "$DOCKER_BUILDTAGS" -test.short -coverprofile=$GOPATH/src/$PACKAGE/coverage.out -coverpkg=$(./coverpkg.sh $PACKAGE $ROOT_PACKAGE) $PACKAGE':
+         timeout: 600
+         pwd: $BASE_STABLE
+
+  post:
+  # Report to codecov
+    - bash <(curl -s https://codecov.io/bash):
+        pwd: $BASE_STABLE
+
+  ## Notes
+  # Disabled the -race detector due to massive memory usage.
+  # Do we want these as well?
+  # - go get code.google.com/p/go.tools/cmd/goimports
+  # - test -z "$(goimports -l -w ./... | tee /dev/stderr)"
+  # http://labix.org/gocheck

vendor/github.com/docker/distribution/context/context.go

@@ -0,0 +1,85 @@
+package context
+
+import (
+	"sync"
+
+	"github.com/docker/distribution/uuid"
+	"golang.org/x/net/context"
+)
+
+// Context is a copy of Context from the golang.org/x/net/context package.
+type Context interface {
+	context.Context
+}
+
+// instanceContext is a context that provides only an instance id. It is
+// provided as the main background context.
+type instanceContext struct {
+	Context
+	id   string    // id of context, logged as "instance.id"
+	once sync.Once // once protect generation of the id
+}
+
+func (ic *instanceContext) Value(key interface{}) interface{} {
+	if key == "instance.id" {
+		ic.once.Do(func() {
+			// We want to lazy initialize the UUID such that we don't
+			// call a random generator from the package initialization
+			// code. For various reasons random could not be available
+			// https://github.com/docker/distribution/issues/782
+			ic.id = uuid.Generate().String()
+		})
+		return ic.id
+	}
+
+	return ic.Context.Value(key)
+}
+
+var background = &instanceContext{
+	Context: context.Background(),
+}
+
+// Background returns a non-nil, empty Context. The background context
+// provides a single key, "instance.id" that is globally unique to the
+// process.
+func Background() Context {
+	return background
+}
+
+// WithValue returns a copy of parent in which the value associated with key is
+// val. Use context Values only for request-scoped data that transits processes
+// and APIs, not for passing optional parameters to functions.
+func WithValue(parent Context, key, val interface{}) Context {
+	return context.WithValue(parent, key, val)
+}
+
+// stringMapContext is a simple context implementation that checks a map for a
+// key, falling back to a parent if not present.
+type stringMapContext struct {
+	context.Context
+	m map[string]interface{}
+}
+
+// WithValues returns a context that proxies lookups through a map. Only
+// supports string keys.
+func WithValues(ctx context.Context, m map[string]interface{}) context.Context {
+	mo := make(map[string]interface{}, len(m)) // make our own copy.
+	for k, v := range m {
+		mo[k] = v
+	}
+
+	return stringMapContext{
+		Context: ctx,
+		m:       mo,
+	}
+}
+
+func (smc stringMapContext) Value(key interface{}) interface{} {
+	if ks, ok := key.(string); ok {
+		if v, ok := smc.m[ks]; ok {
+			return v
+		}
+	}
+
+	return smc.Context.Value(key)
+}

vendor/github.com/docker/distribution/context/doc.go

@@ -0,0 +1,89 @@
+// Package context provides several utilities for working with
+// golang.org/x/net/context in http requests. Primarily, the focus is on
+// logging relevant request information but this package is not limited to
+// that purpose.
+//
+// The easiest way to get started is to get the background context:
+//
+// 	ctx := context.Background()
+//
+// The returned context should be passed around your application and be the
+// root of all other context instances. If the application has a version, this
+// line should be called before anything else:
+//
+// 	ctx := context.WithVersion(context.Background(), version)
+//
+// The above will store the version in the context and will be available to
+// the logger.
+//
+// Logging
+//
+// The most useful aspect of this package is GetLogger. This function takes
+// any context.Context interface and returns the current logger from the
+// context. Canonical usage looks like this:
+//
+// 	GetLogger(ctx).Infof("something interesting happened")
+//
+// GetLogger also takes optional key arguments. The keys will be looked up in
+// the context and reported with the logger. The following example would
+// return a logger that prints the version with each log message:
+//
+// 	ctx := context.Context(context.Background(), "version", version)
+// 	GetLogger(ctx, "version").Infof("this log message has a version field")
+//
+// The above would print out a log message like this:
+//
+// 	INFO[0000] this log message has a version field        version=v2.0.0-alpha.2.m
+//
+// When used with WithLogger, we gain the ability to decorate the context with
+// loggers that have information from disparate parts of the call stack.
+// Following from the version example, we can build a new context with the
+// configured logger such that we always print the version field:
+//
+// 	ctx = WithLogger(ctx, GetLogger(ctx, "version"))
+//
+// Since the logger has been pushed to the context, we can now get the version
+// field for free with our log messages. Future calls to GetLogger on the new
+// context will have the version field:
+//
+// 	GetLogger(ctx).Infof("this log message has a version field")
+//
+// This becomes more powerful when we start stacking loggers. Let's say we
+// have the version logger from above but also want a request id. Using the
+// context above, in our request scoped function, we place another logger in
+// the context:
+//
+// 	ctx = context.WithValue(ctx, "http.request.id", "unique id") // called when building request context
+// 	ctx = WithLogger(ctx, GetLogger(ctx, "http.request.id"))
+//
+// When GetLogger is called on the new context, "http.request.id" will be
+// included as a logger field, along with the original "version" field:
+//
+// 	INFO[0000] this log message has a version field        http.request.id=unique id version=v2.0.0-alpha.2.m
+//
+// Note that this only affects the new context, the previous context, with the
+// version field, can be used independently. Put another way, the new logger,
+// added to the request context, is unique to that context and can have
+// request scoped varaibles.
+//
+// HTTP Requests
+//
+// This package also contains several methods for working with http requests.
+// The concepts are very similar to those described above. We simply place the
+// request in the context using WithRequest. This makes the request variables
+// available. GetRequestLogger can then be called to get request specific
+// variables in a log line:
+//
+// 	ctx = WithRequest(ctx, req)
+// 	GetRequestLogger(ctx).Infof("request variables")
+//
+// Like above, if we want to include the request data in all log messages in
+// the context, we push the logger to a new context and use that one:
+//
+// 	ctx = WithLogger(ctx, GetRequestLogger(ctx))
+//
+// The concept is fairly powerful and ensures that calls throughout the stack
+// can be traced in log messages. Using the fields like "http.request.id", one
+// can analyze call flow for a particular request with a simple grep of the
+// logs.
+package context

vendor/github.com/docker/distribution/context/http.go

@@ -0,0 +1,366 @@
+package context
+
+import (
+	"errors"
+	"net"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
+
+	log "github.com/Sirupsen/logrus"
+	"github.com/docker/distribution/uuid"
+	"github.com/gorilla/mux"
+)
+
+// Common errors used with this package.
+var (
+	ErrNoRequestContext        = errors.New("no http request in context")
+	ErrNoResponseWriterContext = errors.New("no http response in context")
+)
+
+func parseIP(ipStr string) net.IP {
+	ip := net.ParseIP(ipStr)
+	if ip == nil {
+		log.Warnf("invalid remote IP address: %q", ipStr)
+	}
+	return ip
+}
+
+// RemoteAddr extracts the remote address of the request, taking into
+// account proxy headers.
+func RemoteAddr(r *http.Request) string {
+	if prior := r.Header.Get("X-Forwarded-For"); prior != "" {
+		proxies := strings.Split(prior, ",")
+		if len(proxies) > 0 {
+			remoteAddr := strings.Trim(proxies[0], " ")
+			if parseIP(remoteAddr) != nil {
+				return remoteAddr
+			}
+		}
+	}
+	// X-Real-Ip is less supported, but worth checking in the
+	// absence of X-Forwarded-For
+	if realIP := r.Header.Get("X-Real-Ip"); realIP != "" {
+		if parseIP(realIP) != nil {
+			return realIP
+		}
+	}
+
+	return r.RemoteAddr
+}
+
+// RemoteIP extracts the remote IP of the request, taking into
+// account proxy headers.
+func RemoteIP(r *http.Request) string {
+	addr := RemoteAddr(r)
+
+	// Try parsing it as "IP:port"
+	if ip, _, err := net.SplitHostPort(addr); err == nil {
+		return ip
+	}
+
+	return addr
+}
+
+// WithRequest places the request on the context. The context of the request
+// is assigned a unique id, available at "http.request.id". The request itself
+// is available at "http.request". Other common attributes are available under
+// the prefix "http.request.". If a request is already present on the context,
+// this method will panic.
+func WithRequest(ctx Context, r *http.Request) Context {
+	if ctx.Value("http.request") != nil {
+		// NOTE(stevvooe): This needs to be considered a programming error. It
+		// is unlikely that we'd want to have more than one request in
+		// context.
+		panic("only one request per context")
+	}
+
+	return &httpRequestContext{
+		Context:   ctx,
+		startedAt: time.Now(),
+		id:        uuid.Generate().String(),
+		r:         r,
+	}
+}
+
+// GetRequest returns the http request in the given context. Returns
+// ErrNoRequestContext if the context does not have an http request associated
+// with it.
+func GetRequest(ctx Context) (*http.Request, error) {
+	if r, ok := ctx.Value("http.request").(*http.Request); r != nil && ok {
+		return r, nil
+	}
+	return nil, ErrNoRequestContext
+}
+
+// GetRequestID attempts to resolve the current request id, if possible. An
+// error is return if it is not available on the context.
+func GetRequestID(ctx Context) string {
+	return GetStringValue(ctx, "http.request.id")
+}
+
+// WithResponseWriter returns a new context and response writer that makes
+// interesting response statistics available within the context.
+func WithResponseWriter(ctx Context, w http.ResponseWriter) (Context, http.ResponseWriter) {
+	if closeNotifier, ok := w.(http.CloseNotifier); ok {
+		irwCN := &instrumentedResponseWriterCN{
+			instrumentedResponseWriter: instrumentedResponseWriter{
+				ResponseWriter: w,
+				Context:        ctx,
+			},
+			CloseNotifier: closeNotifier,
+		}
+
+		return irwCN, irwCN
+	}
+
+	irw := instrumentedResponseWriter{
+		ResponseWriter: w,
+		Context:        ctx,
+	}
+	return &irw, &irw
+}
+
+// GetResponseWriter returns the http.ResponseWriter from the provided
+// context. If not present, ErrNoResponseWriterContext is returned. The
+// returned instance provides instrumentation in the context.
+func GetResponseWriter(ctx Context) (http.ResponseWriter, error) {
+	v := ctx.Value("http.response")
+
+	rw, ok := v.(http.ResponseWriter)
+	if !ok || rw == nil {
+		return nil, ErrNoResponseWriterContext
+	}
+
+	return rw, nil
+}
+
+// getVarsFromRequest let's us change request vars implementation for testing
+// and maybe future changes.
+var getVarsFromRequest = mux.Vars
+
+// WithVars extracts gorilla/mux vars and makes them available on the returned
+// context. Variables are available at keys with the prefix "vars.". For
+// example, if looking for the variable "name", it can be accessed as
+// "vars.name". Implementations that are accessing values need not know that
+// the underlying context is implemented with gorilla/mux vars.
+func WithVars(ctx Context, r *http.Request) Context {
+	return &muxVarsContext{
+		Context: ctx,
+		vars:    getVarsFromRequest(r),
+	}
+}
+
+// GetRequestLogger returns a logger that contains fields from the request in
+// the current context. If the request is not available in the context, no
+// fields will display. Request loggers can safely be pushed onto the context.
+func GetRequestLogger(ctx Context) Logger {
+	return GetLogger(ctx,
+		"http.request.id",
+		"http.request.method",
+		"http.request.host",
+		"http.request.uri",
+		"http.request.referer",
+		"http.request.useragent",
+		"http.request.remoteaddr",
+		"http.request.contenttype")
+}
+
+// GetResponseLogger reads the current response stats and builds a logger.
+// Because the values are read at call time, pushing a logger returned from
+// this function on the context will lead to missing or invalid data. Only
+// call this at the end of a request, after the response has been written.
+func GetResponseLogger(ctx Context) Logger {
+	l := getLogrusLogger(ctx,
+		"http.response.written",
+		"http.response.status",
+		"http.response.contenttype")
+
+	duration := Since(ctx, "http.request.startedat")
+
+	if duration > 0 {
+		l = l.WithField("http.response.duration", duration.String())
+	}
+
+	return l
+}
+
+// httpRequestContext makes information about a request available to context.
+type httpRequestContext struct {
+	Context
+
+	startedAt time.Time
+	id        string
+	r         *http.Request
+}
+
+// Value returns a keyed element of the request for use in the context. To get
+// the request itself, query "request". For other components, access them as
+// "request.<component>". For example, r.RequestURI
+func (ctx *httpRequestContext) Value(key interface{}) interface{} {
+	if keyStr, ok := key.(string); ok {
+		if keyStr == "http.request" {
+			return ctx.r
+		}
+
+		if !strings.HasPrefix(keyStr, "http.request.") {
+			goto fallback
+		}
+
+		parts := strings.Split(keyStr, ".")
+
+		if len(parts) != 3 {
+			goto fallback
+		}
+
+		switch parts[2] {
+		case "uri":
+			return ctx.r.RequestURI
+		case "remoteaddr":
+			return RemoteAddr(ctx.r)
+		case "method":
+			return ctx.r.Method
+		case "host":
+			return ctx.r.Host
+		case "referer":
+			referer := ctx.r.Referer()
+			if referer != "" {
+				return referer
+			}
+		case "useragent":
+			return ctx.r.UserAgent()
+		case "id":
+			return ctx.id
+		case "startedat":
+			return ctx.startedAt
+		case "contenttype":
+			ct := ctx.r.Header.Get("Content-Type")
+			if ct != "" {
+				return ct
+			}
+		}
+	}
+
+fallback:
+	return ctx.Context.Value(key)
+}
+
+type muxVarsContext struct {
+	Context
+	vars map[string]string
+}
+
+func (ctx *muxVarsContext) Value(key interface{}) interface{} {
+	if keyStr, ok := key.(string); ok {
+		if keyStr == "vars" {
+			return ctx.vars
+		}
+
+		if strings.HasPrefix(keyStr, "vars.") {
+			keyStr = strings.TrimPrefix(keyStr, "vars.")
+		}
+
+		if v, ok := ctx.vars[keyStr]; ok {
+			return v
+		}
+	}
+
+	return ctx.Context.Value(key)
+}
+
+// instrumentedResponseWriterCN provides response writer information in a
+// context. It implements http.CloseNotifier so that users can detect
+// early disconnects.
+type instrumentedResponseWriterCN struct {
+	instrumentedResponseWriter
+	http.CloseNotifier
+}
+
+// instrumentedResponseWriter provides response writer information in a
+// context. This variant is only used in the case where CloseNotifier is not
+// implemented by the parent ResponseWriter.
+type instrumentedResponseWriter struct {
+	http.ResponseWriter
+	Context
+
+	mu      sync.Mutex
+	status  int
+	written int64
+}
+
+func (irw *instrumentedResponseWriter) Write(p []byte) (n int, err error) {
+	n, err = irw.ResponseWriter.Write(p)
+
+	irw.mu.Lock()
+	irw.written += int64(n)
+
+	// Guess the likely status if not set.
+	if irw.status == 0 {
+		irw.status = http.StatusOK
+	}
+
+	irw.mu.Unlock()
+
+	return
+}
+
+func (irw *instrumentedResponseWriter) WriteHeader(status int) {
+	irw.ResponseWriter.WriteHeader(status)
+
+	irw.mu.Lock()
+	irw.status = status
+	irw.mu.Unlock()
+}
+
+func (irw *instrumentedResponseWriter) Flush() {
+	if flusher, ok := irw.ResponseWriter.(http.Flusher); ok {
+		flusher.Flush()
+	}
+}
+
+func (irw *instrumentedResponseWriter) Value(key interface{}) interface{} {
+	if keyStr, ok := key.(string); ok {
+		if keyStr == "http.response" {
+			return irw
+		}
+
+		if !strings.HasPrefix(keyStr, "http.response.") {
+			goto fallback
+		}
+
+		parts := strings.Split(keyStr, ".")
+
+		if len(parts) != 3 {
+			goto fallback
+		}
+
+		irw.mu.Lock()
+		defer irw.mu.Unlock()
+
+		switch parts[2] {
+		case "written":
+			return irw.written
+		case "status":
+			return irw.status
+		case "contenttype":
+			contentType := irw.Header().Get("Content-Type")
+			if contentType != "" {
+				return contentType
+			}
+		}
+	}
+
+fallback:
+	return irw.Context.Value(key)
+}
+
+func (irw *instrumentedResponseWriterCN) Value(key interface{}) interface{} {
+	if keyStr, ok := key.(string); ok {
+		if keyStr == "http.response" {
+			return irw
+		}
+	}
+
+	return irw.instrumentedResponseWriter.Value(key)
+}

vendor/github.com/docker/distribution/context/logger.go

@@ -0,0 +1,116 @@
+package context
+
+import (
+	"fmt"
+
+	"github.com/Sirupsen/logrus"
+	"runtime"
+)
+
+// Logger provides a leveled-logging interface.
+type Logger interface {
+	// standard logger methods
+	Print(args ...interface{})
+	Printf(format string, args ...interface{})
+	Println(args ...interface{})
+
+	Fatal(args ...interface{})
+	Fatalf(format string, args ...interface{})
+	Fatalln(args ...interface{})
+
+	Panic(args ...interface{})
+	Panicf(format string, args ...interface{})
+	Panicln(args ...interface{})
+
+	// Leveled methods, from logrus
+	Debug(args ...interface{})
+	Debugf(format string, args ...interface{})
+	Debugln(args ...interface{})
+
+	Error(args ...interface{})
+	Errorf(format string, args ...interface{})
+	Errorln(args ...interface{})
+
+	Info(args ...interface{})
+	Infof(format string, args ...interface{})
+	Infoln(args ...interface{})
+
+	Warn(args ...interface{})
+	Warnf(format string, args ...interface{})
+	Warnln(args ...interface{})
+}
+
+// WithLogger creates a new context with provided logger.
+func WithLogger(ctx Context, logger Logger) Context {
+	return WithValue(ctx, "logger", logger)
+}
+
+// GetLoggerWithField returns a logger instance with the specified field key
+// and value without affecting the context. Extra specified keys will be
+// resolved from the context.
+func GetLoggerWithField(ctx Context, key, value interface{}, keys ...interface{}) Logger {
+	return getLogrusLogger(ctx, keys...).WithField(fmt.Sprint(key), value)
+}
+
+// GetLoggerWithFields returns a logger instance with the specified fields
+// without affecting the context. Extra specified keys will be resolved from
+// the context.
+func GetLoggerWithFields(ctx Context, fields map[interface{}]interface{}, keys ...interface{}) Logger {
+	// must convert from interface{} -> interface{} to string -> interface{} for logrus.
+	lfields := make(logrus.Fields, len(fields))
+	for key, value := range fields {
+		lfields[fmt.Sprint(key)] = value
+	}
+
+	return getLogrusLogger(ctx, keys...).WithFields(lfields)
+}
+
+// GetLogger returns the logger from the current context, if present. If one
+// or more keys are provided, they will be resolved on the context and
+// included in the logger. While context.Value takes an interface, any key
+// argument passed to GetLogger will be passed to fmt.Sprint when expanded as
+// a logging key field. If context keys are integer constants, for example,
+// its recommended that a String method is implemented.
+func GetLogger(ctx Context, keys ...interface{}) Logger {
+	return getLogrusLogger(ctx, keys...)
+}
+
+// GetLogrusLogger returns the logrus logger for the context. If one more keys
+// are provided, they will be resolved on the context and included in the
+// logger. Only use this function if specific logrus functionality is
+// required.
+func getLogrusLogger(ctx Context, keys ...interface{}) *logrus.Entry {
+	var logger *logrus.Entry
+
+	// Get a logger, if it is present.
+	loggerInterface := ctx.Value("logger")
+	if loggerInterface != nil {
+		if lgr, ok := loggerInterface.(*logrus.Entry); ok {
+			logger = lgr
+		}
+	}
+
+	if logger == nil {
+		fields := logrus.Fields{}
+
+		// Fill in the instance id, if we have it.
+		instanceID := ctx.Value("instance.id")
+		if instanceID != nil {
+			fields["instance.id"] = instanceID
+		}
+
+		fields["go.version"] = runtime.Version()
+		// If no logger is found, just return the standard logger.
+		logger = logrus.StandardLogger().WithFields(fields)
+	}
+
+	fields := logrus.Fields{}
+	for _, key := range keys {
+		v := ctx.Value(key)
+		if v != nil {
+			fields[fmt.Sprint(key)] = v
+		}
+	}
+
+	return logger.WithFields(fields)
+}

vendor/github.com/docker/distribution/context/trace.go

@@ -0,0 +1,104 @@
+package context
+
+import (
+	"runtime"
+	"time"
+
+	"github.com/docker/distribution/uuid"
+)
+
+// WithTrace allocates a traced timing span in a new context. This allows a
+// caller to track the time between calling WithTrace and the returned done
+// function. When the done function is called, a log message is emitted with a
+// "trace.duration" field, corresponding to the elapsed time and a
+// "trace.func" field, corresponding to the function that called WithTrace.
+//
+// The logging keys "trace.id" and "trace.parent.id" are provided to implement
+// dapper-like tracing. This function should be complemented with a WithSpan
+// method that could be used for tracing distributed RPC calls.
+//
+// The main benefit of this function is to post-process log messages or
+// intercept them in a hook to provide timing data. Trace ids and parent ids
+// can also be linked to provide call tracing, if so required.
+//
+// Here is an example of the usage:
+//
+// 	func timedOperation(ctx Context) {
+// 		ctx, done := WithTrace(ctx)
+// 		defer done("this will be the log message")
+// 		// ... function body ...
+// 	}
+//
+// If the function ran for roughly 1s, such a usage would emit a log message
+// as follows:
+//
+// 	INFO[0001] this will be the log message  trace.duration=1.004575763s trace.func=github.com/docker/distribution/context.traceOperation trace.id=<id> ...
+//
+// Notice that the function name is automatically resolved, along with the
+// package and a trace id is emitted that can be linked with parent ids.
+func WithTrace(ctx Context) (Context, func(format string, a ...interface{})) {
+	if ctx == nil {
+		ctx = Background()
+	}
+
+	pc, file, line, _ := runtime.Caller(1)
+	f := runtime.FuncForPC(pc)
+	ctx = &traced{
+		Context: ctx,
+		id:      uuid.Generate().String(),
+		start:   time.Now(),
+		parent:  GetStringValue(ctx, "trace.id"),
+		fnname:  f.Name(),
+		file:    file,
+		line:    line,
+	}
+
+	return ctx, func(format string, a ...interface{}) {
+		GetLogger(ctx,
+			"trace.duration",
+			"trace.id",
+			"trace.parent.id",
+			"trace.func",
+			"trace.file",
+			"trace.line").
+			Debugf(format, a...)
+	}
+}
+
+// traced represents a context that is traced for function call timing. It
+// also provides fast lookup for the various attributes that are available on
+// the trace.
+type traced struct {
+	Context
+	id     string
+	parent string
+	start  time.Time
+	fnname string
+	file   string
+	line   int
+}
+
+func (ts *traced) Value(key interface{}) interface{} {
+	switch key {
+	case "trace.start":
+		return ts.start
+	case "trace.duration":
+		return time.Since(ts.start)
+	case "trace.id":
+		return ts.id
+	case "trace.parent.id":
+		if ts.parent == "" {
+			return nil // must return nil to signal no parent.
+		}
+
+		return ts.parent
+	case "trace.func":
+		return ts.fnname
+	case "trace.file":
+		return ts.file
+	case "trace.line":
+		return ts.line
+	}
+
+	return ts.Context.Value(key)
+}

vendor/github.com/docker/distribution/context/util.go

@@ -0,0 +1,24 @@
+package context
+
+import (
+	"time"
+)
+
+// Since looks up key, which should be a time.Time, and returns the duration
+// since that time. If the key is not found, the value returned will be zero.
+// This is helpful when inferring metrics related to context execution times.
+func Since(ctx Context, key interface{}) time.Duration {
+	if startedAt, ok := ctx.Value(key).(time.Time); ok {
+		return time.Since(startedAt)
+	}
+	return 0
+}
+
+// GetStringValue returns a string value from the context. The empty string
+// will be returned if not found.
+func GetStringValue(ctx Context, key interface{}) (value string) {
+	if valuev, ok := ctx.Value(key).(string); ok {
+		value = valuev
+	}
+	return value
+}

vendor/github.com/docker/distribution/context/version.go

@@ -0,0 +1,16 @@
+package context
+
+// WithVersion stores the application version in the context. The new context
+// gets a logger to ensure log messages are marked with the application
+// version.
+func WithVersion(ctx Context, version string) Context {
+	ctx = WithValue(ctx, "version", version)
+	// push a new logger onto the stack
+	return WithLogger(ctx, GetLogger(ctx, "version"))
+}
+
+// GetVersion returns the application version from the context. An empty
+// string may returned if the version was not set on the context.
+func GetVersion(ctx Context) string {
+	return GetStringValue(ctx, "version")
+}

vendor/github.com/docker/distribution/coverpkg.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+# Given a subpackage and the containing package, figures out which packages
+# need to be passed to `go test -coverpkg`:  this includes all of the
+# subpackage's dependencies within the containing package, as well as the
+# subpackage itself.
+DEPENDENCIES="$(go list -f $'{{range $f := .Deps}}{{$f}}\n{{end}}' ${1} | grep ${2} | grep -v github.com/docker/distribution/vendor)"
+echo "${1} ${DEPENDENCIES}" | xargs echo -n | tr ' ' ','

vendor/github.com/docker/distribution/digest/digest.go

@@ -0,0 +1,139 @@
+package digest
+
+import (
+	"fmt"
+	"hash"
+	"io"
+	"regexp"
+	"strings"
+)
+
+const (
+	// DigestSha256EmptyTar is the canonical sha256 digest of empty data
+	DigestSha256EmptyTar = "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
+)
+
+// Digest allows simple protection of hex formatted digest strings, prefixed
+// by their algorithm. Strings of type Digest have some guarantee of being in
+// the correct format and it provides quick access to the components of a
+// digest string.
+//
+// The following is an example of the contents of Digest types:
+//
+// 	sha256:7173b809ca12ec5dee4506cd86be934c4596dd234ee82c0662eac04a8c2c71dc
+//
+// This allows to abstract the digest behind this type and work only in those
+// terms.
+type Digest string
+
+// NewDigest returns a Digest from alg and a hash.Hash object.
+func NewDigest(alg Algorithm, h hash.Hash) Digest {
+	return NewDigestFromBytes(alg, h.Sum(nil))
+}
+
+// NewDigestFromBytes returns a new digest from the byte contents of p.
+// Typically, this can come from hash.Hash.Sum(...) or xxx.SumXXX(...)
+// functions. This is also useful for rebuilding digests from binary
+// serializations.
+func NewDigestFromBytes(alg Algorithm, p []byte) Digest {
+	return Digest(fmt.Sprintf("%s:%x", alg, p))
+}
+
+// NewDigestFromHex returns a Digest from alg and a the hex encoded digest.
+func NewDigestFromHex(alg, hex string) Digest {
+	return Digest(fmt.Sprintf("%s:%s", alg, hex))
+}
+
+// DigestRegexp matches valid digest types.
+var DigestRegexp = regexp.MustCompile(`[a-zA-Z0-9-_+.]+:[a-fA-F0-9]+`)
+
+// DigestRegexpAnchored matches valid digest types, anchored to the start and end of the match.
+var DigestRegexpAnchored = regexp.MustCompile(`^` + DigestRegexp.String() + `$`)
+
+var (
+	// ErrDigestInvalidFormat returned when digest format invalid.
+	ErrDigestInvalidFormat = fmt.Errorf("invalid checksum digest format")
+
+	// ErrDigestInvalidLength returned when digest has invalid length.
+	ErrDigestInvalidLength = fmt.Errorf("invalid checksum digest length")
+
+	// ErrDigestUnsupported returned when the digest algorithm is unsupported.
+	ErrDigestUnsupported = fmt.Errorf("unsupported digest algorithm")
+)
+
+// ParseDigest parses s and returns the validated digest object. An error will
+// be returned if the format is invalid.
+func ParseDigest(s string) (Digest, error) {
+	d := Digest(s)
+
+	return d, d.Validate()
+}
+
+// FromReader returns the most valid digest for the underlying content using
+// the canonical digest algorithm.
+func FromReader(rd io.Reader) (Digest, error) {
+	return Canonical.FromReader(rd)
+}
+
+// FromBytes digests the input and returns a Digest.
+func FromBytes(p []byte) Digest {
+	return Canonical.FromBytes(p)
+}
+
+// Validate checks that the contents of d is a valid digest, returning an
+// error if not.
+func (d Digest) Validate() error {
+	s := string(d)
+
+	if !DigestRegexpAnchored.MatchString(s) {
+		return ErrDigestInvalidFormat
+	}
+
+	i := strings.Index(s, ":")
+	if i < 0 {
+		return ErrDigestInvalidFormat
+	}
+
+	// case: "sha256:" with no hex.
+	if i+1 == len(s) {
+		return ErrDigestInvalidFormat
+	}
+
+	switch algorithm := Algorithm(s[:i]); algorithm {
+	case SHA256, SHA384, SHA512:
+		if algorithm.Size()*2 != len(s[i+1:]) {
+			return ErrDigestInvalidLength
+		}
+		break
+	default:
+		return ErrDigestUnsupported
+	}
+
+	return nil
+}
+
+// Algorithm returns the algorithm portion of the digest. This will panic if
+// the underlying digest is not in a valid format.
+func (d Digest) Algorithm() Algorithm {
+	return Algorithm(d[:d.sepIndex()])
+}
+
+// Hex returns the hex digest portion of the digest. This will panic if the
+// underlying digest is not in a valid format.
+func (d Digest) Hex() string {
+	return string(d[d.sepIndex()+1:])
+}
+
+func (d Digest) String() string {
+	return string(d)
+}
+
+func (d Digest) sepIndex() int {
+	i := strings.Index(string(d), ":")
+
+	if i < 0 {
+		panic("could not find ':' in digest: " + d)
+	}
+
+	return i
+}

vendor/github.com/docker/distribution/digest/digester.go

@@ -0,0 +1,155 @@
+package digest
+
+import (
+	"crypto"
+	"fmt"
+	"hash"
+	"io"
+)
+
+// Algorithm identifies and implementation of a digester by an identifier.
+// Note the that this defines both the hash algorithm used and the string
+// encoding.
+type Algorithm string
+
+// supported digest types
+const (
+	SHA256 Algorithm = "sha256" // sha256 with hex encoding
+	SHA384 Algorithm = "sha384" // sha384 with hex encoding
+	SHA512 Algorithm = "sha512" // sha512 with hex encoding
+
+	// Canonical is the primary digest algorithm used with the distribution
+	// project. Other digests may be used but this one is the primary storage
+	// digest.
+	Canonical = SHA256
+)
+
+var (
+	// TODO(stevvooe): Follow the pattern of the standard crypto package for
+	// registration of digests. Effectively, we are a registerable set and
+	// common symbol access.
+
+	// algorithms maps values to hash.Hash implementations. Other algorithms
+	// may be available but they cannot be calculated by the digest package.
+	algorithms = map[Algorithm]crypto.Hash{
+		SHA256: crypto.SHA256,
+		SHA384: crypto.SHA384,
+		SHA512: crypto.SHA512,
+	}
+)
+
+// Available returns true if the digest type is available for use. If this
+// returns false, New and Hash will return nil.
+func (a Algorithm) Available() bool {
+	h, ok := algorithms[a]
+	if !ok {
+		return false
+	}
+
+	// check availability of the hash, as well
+	return h.Available()
+}
+
+func (a Algorithm) String() string {
+	return string(a)
+}
+
+// Size returns number of bytes returned by the hash.
+func (a Algorithm) Size() int {
+	h, ok := algorithms[a]
+	if !ok {
+		return 0
+	}
+	return h.Size()
+}
+
+// Set implemented to allow use of Algorithm as a command line flag.
+func (a *Algorithm) Set(value string) error {
+	if value == "" {
+		*a = Canonical
+	} else {
+		// just do a type conversion, support is queried with Available.
+		*a = Algorithm(value)
+	}
+
+	return nil
+}
+
+// New returns a new digester for the specified algorithm. If the algorithm
+// does not have a digester implementation, nil will be returned. This can be
+// checked by calling Available before calling New.
+func (a Algorithm) New() Digester {
+	return &digester{
+		alg:  a,
+		hash: a.Hash(),
+	}
+}
+
+// Hash returns a new hash as used by the algorithm. If not available, the
+// method will panic. Check Algorithm.Available() before calling.
+func (a Algorithm) Hash() hash.Hash {
+	if !a.Available() {
+		// NOTE(stevvooe): A missing hash is usually a programming error that
+		// must be resolved at compile time. We don't import in the digest
+		// package to allow users to choose their hash implementation (such as
+		// when using stevvooe/resumable or a hardware accelerated package).
+		//
+		// Applications that may want to resolve the hash at runtime should
+		// call Algorithm.Available before call Algorithm.Hash().
+		panic(fmt.Sprintf("%v not available (make sure it is imported)", a))
+	}
+
+	return algorithms[a].New()
+}
+
+// FromReader returns the digest of the reader using the algorithm.
+func (a Algorithm) FromReader(rd io.Reader) (Digest, error) {
+	digester := a.New()
+
+	if _, err := io.Copy(digester.Hash(), rd); err != nil {
+		return "", err
+	}
+
+	return digester.Digest(), nil
+}
+
+// FromBytes digests the input and returns a Digest.
+func (a Algorithm) FromBytes(p []byte) Digest {
+	digester := a.New()
+
+	if _, err := digester.Hash().Write(p); err != nil {
+		// Writes to a Hash should never fail. None of the existing
+		// hash implementations in the stdlib or hashes vendored
+		// here can return errors from Write. Having a panic in this
+		// condition instead of having FromBytes return an error value
+		// avoids unnecessary error handling paths in all callers.
+		panic("write to hash function returned error: " + err.Error())
+	}
+
+	return digester.Digest()
+}
+
+// TODO(stevvooe): Allow resolution of verifiers using the digest type and
+// this registration system.
+
+// Digester calculates the digest of written data. Writes should go directly
+// to the return value of Hash, while calling Digest will return the current
+// value of the digest.
+type Digester interface {
+	Hash() hash.Hash // provides direct access to underlying hash instance.
+	Digest() Digest
+}
+
+// digester provides a simple digester definition that embeds a hasher.
+type digester struct {
+	alg  Algorithm
+	hash hash.Hash
+}
+
+func (d *digester) Hash() hash.Hash {
+	return d.hash
+}
+
+func (d *digester) Digest() Digest {
+	return NewDigest(d.alg, d.hash)
+}

vendor/github.com/docker/distribution/digest/doc.go

@@ -0,0 +1,42 @@
+// Package digest provides a generalized type to opaquely represent message
+// digests and their operations within the registry. The Digest type is
+// designed to serve as a flexible identifier in a content-addressable system.
+// More importantly, it provides tools and wrappers to work with
+// hash.Hash-based digests with little effort.
+//
+// Basics
+//
+// The format of a digest is simply a string with two parts, dubbed the
+// "algorithm" and the "digest", separated by a colon:
+//
+// 	<algorithm>:<digest>
+//
+// An example of a sha256 digest representation follows:
+//
+// 	sha256:7173b809ca12ec5dee4506cd86be934c4596dd234ee82c0662eac04a8c2c71dc
+//
+// In this case, the string "sha256" is the algorithm and the hex bytes are
+// the "digest".
+//
+// Because the Digest type is simply a string, once a valid Digest is
+// obtained, comparisons are cheap, quick and simple to express with the
+// standard equality operator.
+//
+// Verification
+//
+// The main benefit of using the Digest type is simple verification against a
+// given digest. The Verifier interface, modeled after the stdlib hash.Hash
+// interface, provides a common write sink for digest verification. After
+// writing is complete, calling the Verifier.Verified method will indicate
+// whether or not the stream of bytes matches the target digest.
+//
+// Missing Features
+//
+// In addition to the above, we intend to add the following features to this
+// package:
+//
+// 1. A Digester type that supports write sink digest calculation.
+//
+// 2. Suspend and resume of ongoing digest calculations to support efficient digest verification in the registry.
+//
+package digest

vendor/github.com/docker/distribution/digest/set.go

@@ -0,0 +1,245 @@
+package digest
+
+import (
+	"errors"
+	"sort"
+	"strings"
+	"sync"
+)
+
+var (
+	// ErrDigestNotFound is used when a matching digest
+	// could not be found in a set.
+	ErrDigestNotFound = errors.New("digest not found")
+
+	// ErrDigestAmbiguous is used when multiple digests
+	// are found in a set. None of the matching digests
+	// should be considered valid matches.
+	ErrDigestAmbiguous = errors.New("ambiguous digest string")
+)
+
+// Set is used to hold a unique set of digests which
+// may be easily referenced by easily  referenced by a string
+// representation of the digest as well as short representation.
+// The uniqueness of the short representation is based on other
+// digests in the set. If digests are omitted from this set,
+// collisions in a larger set may not be detected, therefore it
+// is important to always do short representation lookups on
+// the complete set of digests. To mitigate collisions, an
+// appropriately long short code should be used.
+type Set struct {
+	mutex   sync.RWMutex
+	entries digestEntries
+}
+
+// NewSet creates an empty set of digests
+// which may have digests added.
+func NewSet() *Set {
+	return &Set{
+		entries: digestEntries{},
+	}
+}
+
+// checkShortMatch checks whether two digests match as either whole
+// values or short values. This function does not test equality,
+// rather whether the second value could match against the first
+// value.
+func checkShortMatch(alg Algorithm, hex, shortAlg, shortHex string) bool {
+	if len(hex) == len(shortHex) {
+		if hex != shortHex {
+			return false
+		}
+		if len(shortAlg) > 0 && string(alg) != shortAlg {
+			return false
+		}
+	} else if !strings.HasPrefix(hex, shortHex) {
+		return false
+	} else if len(shortAlg) > 0 && string(alg) != shortAlg {
+		return false
+	}
+	return true
+}
+
+// Lookup looks for a digest matching the given string representation.
+// If no digests could be found ErrDigestNotFound will be returned
+// with an empty digest value. If multiple matches are found
+// ErrDigestAmbiguous will be returned with an empty digest value.
+func (dst *Set) Lookup(d string) (Digest, error) {
+	dst.mutex.RLock()
+	defer dst.mutex.RUnlock()
+	if len(dst.entries) == 0 {
+		return "", ErrDigestNotFound
+	}
+	var (
+		searchFunc func(int) bool
+		alg        Algorithm
+		hex        string
+	)
+	dgst, err := ParseDigest(d)
+	if err == ErrDigestInvalidFormat {
+		hex = d
+		searchFunc = func(i int) bool {
+			return dst.entries[i].val >= d
+		}
+	} else {
+		hex = dgst.Hex()
+		alg = dgst.Algorithm()
+		searchFunc = func(i int) bool {
+			if dst.entries[i].val == hex {
+				return dst.entries[i].alg >= alg
+			}
+			return dst.entries[i].val >= hex
+		}
+	}
+	idx := sort.Search(len(dst.entries), searchFunc)
+	if idx == len(dst.entries) || !checkShortMatch(dst.entries[idx].alg, dst.entries[idx].val, string(alg), hex) {
+		return "", ErrDigestNotFound
+	}
+	if dst.entries[idx].alg == alg && dst.entries[idx].val == hex {
+		return dst.entries[idx].digest, nil
+	}
+	if idx+1 < len(dst.entries) && checkShortMatch(dst.entries[idx+1].alg, dst.entries[idx+1].val, string(alg), hex) {
+		return "", ErrDigestAmbiguous
+	}
+
+	return dst.entries[idx].digest, nil
+}
+
+// Add adds the given digest to the set. An error will be returned
+// if the given digest is invalid. If the digest already exists in the
+// set, this operation will be a no-op.
+func (dst *Set) Add(d Digest) error {
+	if err := d.Validate(); err != nil {
+		return err
+	}
+	dst.mutex.Lock()
+	defer dst.mutex.Unlock()
+	entry := &digestEntry{alg: d.Algorithm(), val: d.Hex(), digest: d}
+	searchFunc := func(i int) bool {
+		if dst.entries[i].val == entry.val {
+			return dst.entries[i].alg >= entry.alg
+		}
+		return dst.entries[i].val >= entry.val
+	}
+	idx := sort.Search(len(dst.entries), searchFunc)
+	if idx == len(dst.entries) {
+		dst.entries = append(dst.entries, entry)
+		return nil
+	} else if dst.entries[idx].digest == d {
+		return nil
+	}
+
+	entries := append(dst.entries, nil)
+	copy(entries[idx+1:], entries[idx:len(entries)-1])
+	entries[idx] = entry
+	dst.entries = entries
+	return nil
+}
+
+// Remove removes the given digest from the set. An err will be
+// returned if the given digest is invalid. If the digest does
+// not exist in the set, this operation will be a no-op.
+func (dst *Set) Remove(d Digest) error {
+	if err := d.Validate(); err != nil {
+		return err
+	}
+	dst.mutex.Lock()
+	defer dst.mutex.Unlock()
+	entry := &digestEntry{alg: d.Algorithm(), val: d.Hex(), digest: d}
+	searchFunc := func(i int) bool {
+		if dst.entries[i].val == entry.val {
+			return dst.entries[i].alg >= entry.alg
+		}
+		return dst.entries[i].val >= entry.val
+	}
+	idx := sort.Search(len(dst.entries), searchFunc)
+	// Not found if idx is after or value at idx is not digest
+	if idx == len(dst.entries) || dst.entries[idx].digest != d {
+		return nil
+	}
+
+	entries := dst.entries
+	copy(entries[idx:], entries[idx+1:])
+	entries = entries[:len(entries)-1]
+	dst.entries = entries
+
+	return nil
+}
+
+// All returns all the digests in the set
+func (dst *Set) All() []Digest {
+	dst.mutex.RLock()
+	defer dst.mutex.RUnlock()
+	retValues := make([]Digest, len(dst.entries))
+	for i := range dst.entries {
+		retValues[i] = dst.entries[i].digest
+	}
+
+	return retValues
+}
+
+// ShortCodeTable returns a map of Digest to unique short codes. The
+// length represents the minimum value, the maximum length may be the
+// entire value of digest if uniqueness cannot be achieved without the
+// full value. This function will attempt to make short codes as short
+// as possible to be unique.
+func ShortCodeTable(dst *Set, length int) map[Digest]string {
+	dst.mutex.RLock()
+	defer dst.mutex.RUnlock()
+	m := make(map[Digest]string, len(dst.entries))
+	l := length
+	resetIdx := 0
+	for i := 0; i < len(dst.entries); i++ {
+		var short string
+		extended := true
+		for extended {
+			extended = false
+			if len(dst.entries[i].val) <= l {
+				short = dst.entries[i].digest.String()
+			} else {
+				short = dst.entries[i].val[:l]
+				for j := i + 1; j < len(dst.entries); j++ {
+					if checkShortMatch(dst.entries[j].alg, dst.entries[j].val, "", short) {
+						if j > resetIdx {
+							resetIdx = j
+						}
+						extended = true
+					} else {
+						break
+					}
+				}
+				if extended {
+					l++
+				}
+			}
+		}
+		m[dst.entries[i].digest] = short
+		if i >= resetIdx {
+			l = length
+		}
+	}
+	return m
+}
+
+type digestEntry struct {
+	alg    Algorithm
+	val    string
+	digest Digest
+}
+
+type digestEntries []*digestEntry
+
+func (d digestEntries) Len() int {
+	return len(d)
+}
+
+func (d digestEntries) Less(i, j int) bool {
+	if d[i].val != d[j].val {
+		return d[i].val < d[j].val
+	}
+	return d[i].alg < d[j].alg
+}
+
+func (d digestEntries) Swap(i, j int) {
+	d[i], d[j] = d[j], d[i]
+}

vendor/github.com/docker/distribution/digest/verifiers.go

@@ -0,0 +1,44 @@
+package digest
+
+import (
+	"hash"
+	"io"
+)
+
+// Verifier presents a general verification interface to be used with message
+// digests and other byte stream verifications. Users instantiate a Verifier
+// from one of the various methods, write the data under test to it then check
+// the result with the Verified method.
+type Verifier interface {
+	io.Writer
+
+	// Verified will return true if the content written to Verifier matches
+	// the digest.
+	Verified() bool
+}
+
+// NewDigestVerifier returns a verifier that compares the written bytes
+// against a passed in digest.
+func NewDigestVerifier(d Digest) (Verifier, error) {
+	if err := d.Validate(); err != nil {
+		return nil, err
+	}
+
+	return hashVerifier{
+		hash:   d.Algorithm().Hash(),
+		digest: d,
+	}, nil
+}
+
+type hashVerifier struct {
+	digest Digest
+	hash   hash.Hash
+}
+
+func (hv hashVerifier) Write(p []byte) (n int, err error) {
+	return hv.hash.Write(p)
+}
+
+func (hv hashVerifier) Verified() bool {
+	return hv.digest == NewDigest(hv.digest.Algorithm(), hv.hash)
+}

vendor/github.com/docker/distribution/doc.go

@@ -0,0 +1,7 @@
+// Package distribution will define the interfaces for the components of
+// docker distribution. The goal is to allow users to reliably package, ship
+// and store content related to docker images.
+//
+// This is currently a work in progress. More details are available in the
+// README.md.
+package distribution

vendor/github.com/docker/distribution/errors.go

@@ -0,0 +1,115 @@
+package distribution
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/docker/distribution/digest"
+)
+
+// ErrAccessDenied is returned when an access to a requested resource is
+// denied.
+var ErrAccessDenied = errors.New("access denied")
+
+// ErrManifestNotModified is returned when a conditional manifest GetByTag
+// returns nil due to the client indicating it has the latest version
+var ErrManifestNotModified = errors.New("manifest not modified")
+
+// ErrUnsupported is returned when an unimplemented or unsupported action is
+// performed
+var ErrUnsupported = errors.New("operation unsupported")
+
+// ErrTagUnknown is returned if the given tag is not known by the tag service
+type ErrTagUnknown struct {
+	Tag string
+}
+
+func (err ErrTagUnknown) Error() string {
+	return fmt.Sprintf("unknown tag=%s", err.Tag)
+}
+
+// ErrRepositoryUnknown is returned if the named repository is not known by
+// the registry.
+type ErrRepositoryUnknown struct {
+	Name string
+}
+
+func (err ErrRepositoryUnknown) Error() string {
+	return fmt.Sprintf("unknown repository name=%s", err.Name)
+}
+
+// ErrRepositoryNameInvalid should be used to denote an invalid repository
+// name. Reason may set, indicating the cause of invalidity.
+type ErrRepositoryNameInvalid struct {
+	Name   string
+	Reason error
+}
+
+func (err ErrRepositoryNameInvalid) Error() string {
+	return fmt.Sprintf("repository name %q invalid: %v", err.Name, err.Reason)
+}
+
+// ErrManifestUnknown is returned if the manifest is not known by the
+// registry.
+type ErrManifestUnknown struct {
+	Name string
+	Tag  string
+}
+
+func (err ErrManifestUnknown) Error() string {
+	return fmt.Sprintf("unknown manifest name=%s tag=%s", err.Name, err.Tag)
+}
+
+// ErrManifestUnknownRevision is returned when a manifest cannot be found by
+// revision within a repository.
+type ErrManifestUnknownRevision struct {
+	Name     string
+	Revision digest.Digest
+}
+
+func (err ErrManifestUnknownRevision) Error() string {
+	return fmt.Sprintf("unknown manifest name=%s revision=%s", err.Name, err.Revision)
+}
+
+// ErrManifestUnverified is returned when the registry is unable to verify
+// the manifest.
+type ErrManifestUnverified struct{}
+
+func (ErrManifestUnverified) Error() string {
+	return fmt.Sprintf("unverified manifest")
+}
+
+// ErrManifestVerification provides a type to collect errors encountered
+// during manifest verification. Currently, it accepts errors of all types,
+// but it may be narrowed to those involving manifest verification.
+type ErrManifestVerification []error
+
+func (errs ErrManifestVerification) Error() string {
+	var parts []string
+	for _, err := range errs {
+		parts = append(parts, err.Error())
+	}
+
+	return fmt.Sprintf("errors verifying manifest: %v", strings.Join(parts, ","))
+}
+
+// ErrManifestBlobUnknown returned when a referenced blob cannot be found.
+type ErrManifestBlobUnknown struct {
+	Digest digest.Digest
+}
+
+func (err ErrManifestBlobUnknown) Error() string {
+	return fmt.Sprintf("unknown blob %v on manifest", err.Digest)
+}
+
+// ErrManifestNameInvalid should be used to denote an invalid manifest
+// name. Reason may set, indicating the cause of invalidity.
+type ErrManifestNameInvalid struct {
+	Name   string
+	Reason error
+}
+
+func (err ErrManifestNameInvalid) Error() string {
+	return fmt.Sprintf("manifest name %q invalid: %v", err.Name, err.Reason)
+}

vendor/github.com/docker/distribution/manifests.go

@@ -0,0 +1,117 @@
+package distribution
+
+import (
+	"fmt"
+	"mime"
+
+	"github.com/docker/distribution/context"
+	"github.com/docker/distribution/digest"
+)
+
+// Manifest represents a registry object specifying a set of
+// references and an optional target
+type Manifest interface {
+	// References returns a list of objects which make up this manifest.
+	// The references are strictly ordered from base to head. A reference
+	// is anything which can be represented by a distribution.Descriptor
+	References() []Descriptor
+
+	// Payload provides the serialized format of the manifest, in addition to
+	// the mediatype.
+	Payload() (mediatype string, payload []byte, err error)
+}
+
+// ManifestBuilder creates a manifest allowing one to include dependencies.
+// Instances can be obtained from a version-specific manifest package.  Manifest
+// specific data is passed into the function which creates the builder.
+type ManifestBuilder interface {
+	// Build creates the manifest from his builder.
+	Build(ctx context.Context) (Manifest, error)
+
+	// References returns a list of objects which have been added to this
+	// builder. The dependencies are returned in the order they were added,
+	// which should be from base to head.
+	References() []Descriptor
+
+	// AppendReference includes the given object in the manifest after any
+	// existing dependencies. If the add fails, such as when adding an
+	// unsupported dependency, an error may be returned.
+	AppendReference(dependency Describable) error
+}
+
+// ManifestService describes operations on image manifests.
+type ManifestService interface {
+	// Exists returns true if the manifest exists.
+	Exists(ctx context.Context, dgst digest.Digest) (bool, error)
+
+	// Get retrieves the manifest specified by the given digest
+	Get(ctx context.Context, dgst digest.Digest, options ...ManifestServiceOption) (Manifest, error)
+
+	// Put creates or updates the given manifest returning the manifest digest
+	Put(ctx context.Context, manifest Manifest, options ...ManifestServiceOption) (digest.Digest, error)
+
+	// Delete removes the manifest specified by the given digest. Deleting
+	// a manifest that doesn't exist will return ErrManifestNotFound
+	Delete(ctx context.Context, dgst digest.Digest) error
+}
+
+// ManifestEnumerator enables iterating over manifests
+type ManifestEnumerator interface {
+	// Enumerate calls ingester for each manifest.
+	Enumerate(ctx context.Context, ingester func(digest.Digest) error) error
+}
+
+// Describable is an interface for descriptors
+type Describable interface {
+	Descriptor() Descriptor
+}
+
+// ManifestMediaTypes returns the supported media types for manifests.
+func ManifestMediaTypes() (mediaTypes []string) {
+	for t := range mappings {
+		if t != "" {
+			mediaTypes = append(mediaTypes, t)
+		}
+	}
+	return
+}
+
+// UnmarshalFunc implements manifest unmarshalling a given MediaType
+type UnmarshalFunc func([]byte) (Manifest, Descriptor, error)
+
+var mappings = make(map[string]UnmarshalFunc, 0)
+
+// UnmarshalManifest looks up manifest unmarshal functions based on
+// MediaType
+func UnmarshalManifest(ctHeader string, p []byte) (Manifest, Descriptor, error) {
+	// Need to look up by the actual media type, not the raw contents of
+	// the header. Strip semicolons and anything following them.
+	var mediatype string
+	if ctHeader != "" {
+		var err error
+		mediatype, _, err = mime.ParseMediaType(ctHeader)
+		if err != nil {
+			return nil, Descriptor{}, err
+		}
+	}
+
+	unmarshalFunc, ok := mappings[mediatype]
+	if !ok {
+		unmarshalFunc, ok = mappings[""]
+		if !ok {
+			return nil, Descriptor{}, fmt.Errorf("unsupported manifest mediatype and no default available: %s", mediatype)
+		}
+	}
+
+	return unmarshalFunc(p)
+}
+
+// RegisterManifestSchema registers an UnmarshalFunc for a given schema type.  This
+// should be called from specific
+func RegisterManifestSchema(mediatype string, u UnmarshalFunc) error {
+	if _, ok := mappings[mediatype]; ok {
+		return fmt.Errorf("manifest mediatype registration would overwrite existing: %s", mediatype)
+	}
+	mappings[mediatype] = u
+	return nil
+}

vendor/github.com/docker/distribution/reference/reference.go

@@ -0,0 +1,334 @@
+// Package reference provides a general type to represent any way of referencing images within the registry.
+// Its main purpose is to abstract tags and digests (content-addressable hash).
+//
+// Grammar
+//
+// 	reference                       := name [ ":" tag ] [ "@" digest ]
+//	name                            := [hostname '/'] component ['/' component]*
+//	hostname                        := hostcomponent ['.' hostcomponent]* [':' port-number]
+//	hostcomponent                   := /([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])/
+//	port-number                     := /[0-9]+/
+//	component                       := alpha-numeric [separator alpha-numeric]*
+// 	alpha-numeric                   := /[a-z0-9]+/
+//	separator                       := /[_.]|__|[-]*/
+//
+//	tag                             := /[\w][\w.-]{0,127}/
+//
+//	digest                          := digest-algorithm ":" digest-hex
+//	digest-algorithm                := digest-algorithm-component [ digest-algorithm-separator digest-algorithm-component ]
+//	digest-algorithm-separator      := /[+.-_]/
+//	digest-algorithm-component      := /[A-Za-z][A-Za-z0-9]*/
+//	digest-hex                      := /[0-9a-fA-F]{32,}/ ; At least 128 bit digest value
+package reference
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/docker/distribution/digest"
+)
+
+const (
+	// NameTotalLengthMax is the maximum total number of characters in a repository name.
+	NameTotalLengthMax = 255
+)
+
+var (
+	// ErrReferenceInvalidFormat represents an error while trying to parse a string as a reference.
+	ErrReferenceInvalidFormat = errors.New("invalid reference format")
+
+	// ErrTagInvalidFormat represents an error while trying to parse a string as a tag.
+	ErrTagInvalidFormat = errors.New("invalid tag format")
+
+	// ErrDigestInvalidFormat represents an error while trying to parse a string as a tag.
+	ErrDigestInvalidFormat = errors.New("invalid digest format")
+
+	// ErrNameEmpty is returned for empty, invalid repository names.
+	ErrNameEmpty = errors.New("repository name must have at least one component")
+
+	// ErrNameTooLong is returned when a repository name is longer than NameTotalLengthMax.
+	ErrNameTooLong = fmt.Errorf("repository name must not be more than %v characters", NameTotalLengthMax)
+)
+
+// Reference is an opaque object reference identifier that may include
+// modifiers such as a hostname, name, tag, and digest.
+type Reference interface {
+	// String returns the full reference
+	String() string
+}
+
+// Field provides a wrapper type for resolving correct reference types when
+// working with encoding.
+type Field struct {
+	reference Reference
+}
+
+// AsField wraps a reference in a Field for encoding.
+func AsField(reference Reference) Field {
+	return Field{reference}
+}
+
+// Reference unwraps the reference type from the field to
+// return the Reference object. This object should be
+// of the appropriate type to further check for different
+// reference types.
+func (f Field) Reference() Reference {
+	return f.reference
+}
+
+// MarshalText serializes the field to byte text which
+// is the string of the reference.
+func (f Field) MarshalText() (p []byte, err error) {
+	return []byte(f.reference.String()), nil
+}
+
+// UnmarshalText parses text bytes by invoking the
+// reference parser to ensure the appropriately
+// typed reference object is wrapped by field.
+func (f *Field) UnmarshalText(p []byte) error {
+	r, err := Parse(string(p))
+	if err != nil {
+		return err
+	}
+
+	f.reference = r
+	return nil
+}
+
+// Named is an object with a full name
+type Named interface {
+	Reference
+	Name() string
+}
+
+// Tagged is an object which has a tag
+type Tagged interface {
+	Reference
+	Tag() string
+}
+
+// NamedTagged is an object including a name and tag.
+type NamedTagged interface {
+	Named
+	Tag() string
+}
+
+// Digested is an object which has a digest
+// in which it can be referenced by
+type Digested interface {
+	Reference
+	Digest() digest.Digest
+}
+
+// Canonical reference is an object with a fully unique
+// name including a name with hostname and digest
+type Canonical interface {
+	Named
+	Digest() digest.Digest
+}
+
+// SplitHostname splits a named reference into a
+// hostname and name string. If no valid hostname is
+// found, the hostname is empty and the full value
+// is returned as name
+func SplitHostname(named Named) (string, string) {
+	name := named.Name()
+	match := anchoredNameRegexp.FindStringSubmatch(name)
+	if match == nil || len(match) != 3 {
+		return "", name
+	}
+	return match[1], match[2]
+}
+
+// Parse parses s and returns a syntactically valid Reference.
+// If an error was encountered it is returned, along with a nil Reference.
+// NOTE: Parse will not handle short digests.
+func Parse(s string) (Reference, error) {
+	matches := ReferenceRegexp.FindStringSubmatch(s)
+	if matches == nil {
+		if s == "" {
+			return nil, ErrNameEmpty
+		}
+		// TODO(dmcgowan): Provide more specific and helpful error
+		return nil, ErrReferenceInvalidFormat
+	}
+
+	if len(matches[1]) > NameTotalLengthMax {
+		return nil, ErrNameTooLong
+	}
+
+	ref := reference{
+		name: matches[1],
+		tag:  matches[2],
+	}
+	if matches[3] != "" {
+		var err error
+		ref.digest, err = digest.ParseDigest(matches[3])
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	r := getBestReferenceType(ref)
+	if r == nil {
+		return nil, ErrNameEmpty
+	}
+
+	return r, nil
+}
+
+// ParseNamed parses s and returns a syntactically valid reference implementing
+// the Named interface. The reference must have a name, otherwise an error is
+// returned.
+// If an error was encountered it is returned, along with a nil Reference.
+// NOTE: ParseNamed will not handle short digests.
+func ParseNamed(s string) (Named, error) {
+	ref, err := Parse(s)
+	if err != nil {
+		return nil, err
+	}
+	named, isNamed := ref.(Named)
+	if !isNamed {
+		return nil, fmt.Errorf("reference %s has no name", ref.String())
+	}
+	return named, nil
+}
+
+// WithName returns a named object representing the given string. If the input
+// is invalid ErrReferenceInvalidFormat will be returned.
+func WithName(name string) (Named, error) {
+	if len(name) > NameTotalLengthMax {
+		return nil, ErrNameTooLong
+	}
+	if !anchoredNameRegexp.MatchString(name) {
+		return nil, ErrReferenceInvalidFormat
+	}
+	return repository(name), nil
+}
+
+// WithTag combines the name from "name" and the tag from "tag" to form a
+// reference incorporating both the name and the tag.
+func WithTag(name Named, tag string) (NamedTagged, error) {
+	if !anchoredTagRegexp.MatchString(tag) {
+		return nil, ErrTagInvalidFormat
+	}
+	return taggedReference{
+		name: name.Name(),
+		tag:  tag,
+	}, nil
+}
+
+// WithDigest combines the name from "name" and the digest from "digest" to form
+// a reference incorporating both the name and the digest.
+func WithDigest(name Named, digest digest.Digest) (Canonical, error) {
+	if !anchoredDigestRegexp.MatchString(digest.String()) {
+		return nil, ErrDigestInvalidFormat
+	}
+	return canonicalReference{
+		name:   name.Name(),
+		digest: digest,
+	}, nil
+}
+
+func getBestReferenceType(ref reference) Reference {
+	if ref.name == "" {
+		// Allow digest only references
+		if ref.digest != "" {
+			return digestReference(ref.digest)
+		}
+		return nil
+	}
+	if ref.tag == "" {
+		if ref.digest != "" {
+			return canonicalReference{
+				name:   ref.name,
+				digest: ref.digest,
+			}
+		}
+		return repository(ref.name)
+	}
+	if ref.digest == "" {
+		return taggedReference{
+			name: ref.name,
+			tag:  ref.tag,
+		}
+	}
+
+	return ref
+}
+
+type reference struct {
+	name   string
+	tag    string
+	digest digest.Digest
+}
+
+func (r reference) String() string {
+	return r.name + ":" + r.tag + "@" + r.digest.String()
+}
+
+func (r reference) Name() string {
+	return r.name
+}
+
+func (r reference) Tag() string {
+	return r.tag
+}
+
+func (r reference) Digest() digest.Digest {
+	return r.digest
+}
+
+type repository string
+
+func (r repository) String() string {
+	return string(r)
+}
+
+func (r repository) Name() string {
+	return string(r)
+}
+
+type digestReference digest.Digest
+
+func (d digestReference) String() string {
+	return d.String()
+}
+
+func (d digestReference) Digest() digest.Digest {
+	return digest.Digest(d)
+}
+
+type taggedReference struct {
+	name string
+	tag  string
+}
+
+func (t taggedReference) String() string {
+	return t.name + ":" + t.tag
+}
+
+func (t taggedReference) Name() string {
+	return t.name
+}
+
+func (t taggedReference) Tag() string {
+	return t.tag
+}
+
+type canonicalReference struct {
+	name   string
+	digest digest.Digest
+}
+
+func (c canonicalReference) String() string {
+	return c.name + "@" + c.digest.String()
+}
+
+func (c canonicalReference) Name() string {
+	return c.name
+}
+
+func (c canonicalReference) Digest() digest.Digest {
+	return c.digest
+}

vendor/github.com/docker/distribution/reference/regexp.go

@@ -0,0 +1,124 @@
+package reference
+
+import "regexp"
+
+var (
+	// alphaNumericRegexp defines the alpha numeric atom, typically a
+	// component of names. This only allows lower case characters and digits.
+	alphaNumericRegexp = match(`[a-z0-9]+`)
+
+	// separatorRegexp defines the separators allowed to be embedded in name
+	// components. This allow one period, one or two underscore and multiple
+	// dashes.
+	separatorRegexp = match(`(?:[._]|__|[-]*)`)
+
+	// nameComponentRegexp restricts registry path component names to start
+	// with at least one letter or number, with following parts able to be
+	// separated by one period, one or two underscore and multiple dashes.
+	nameComponentRegexp = expression(
+		alphaNumericRegexp,
+		optional(repeated(separatorRegexp, alphaNumericRegexp)))
+
+	// hostnameComponentRegexp restricts the registry hostname component of a
+	// repository name to start with a component as defined by hostnameRegexp
+	// and followed by an optional port.
+	hostnameComponentRegexp = match(`(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9-]*[a-zA-Z0-9])`)
+
+	// hostnameRegexp defines the structure of potential hostname components
+	// that may be part of image names. This is purposely a subset of what is
+	// allowed by DNS to ensure backwards compatibility with Docker image
+	// names.
+	hostnameRegexp = expression(
+		hostnameComponentRegexp,
+		optional(repeated(literal(`.`), hostnameComponentRegexp)),
+		optional(literal(`:`), match(`[0-9]+`)))
+
+	// TagRegexp matches valid tag names. From docker/docker:graph/tags.go.
+	TagRegexp = match(`[\w][\w.-]{0,127}`)
+
+	// anchoredTagRegexp matches valid tag names, anchored at the start and
+	// end of the matched string.
+	anchoredTagRegexp = anchored(TagRegexp)
+
+	// DigestRegexp matches valid digests.
+	DigestRegexp = match(`[A-Za-z][A-Za-z0-9]*(?:[-_+.][A-Za-z][A-Za-z0-9]*)*[:][[:xdigit:]]{32,}`)
+
+	// anchoredDigestRegexp matches valid digests, anchored at the start and
+	// end of the matched string.
+	anchoredDigestRegexp = anchored(DigestRegexp)
+
+	// NameRegexp is the format for the name component of references. The
+	// regexp has capturing groups for the hostname and name part omitting
+	// the separating forward slash from either.
+	NameRegexp = expression(
+		optional(hostnameRegexp, literal(`/`)),
+		nameComponentRegexp,
+		optional(repeated(literal(`/`), nameComponentRegexp)))
+
+	// anchoredNameRegexp is used to parse a name value, capturing the
+	// hostname and trailing components.
+	anchoredNameRegexp = anchored(
+		optional(capture(hostnameRegexp), literal(`/`)),
+		capture(nameComponentRegexp,
+			optional(repeated(literal(`/`), nameComponentRegexp))))
+
+	// ReferenceRegexp is the full supported format of a reference. The regexp
+	// is anchored and has capturing groups for name, tag, and digest
+	// components.
+	ReferenceRegexp = anchored(capture(NameRegexp),
+		optional(literal(":"), capture(TagRegexp)),
+		optional(literal("@"), capture(DigestRegexp)))
+)
+
+// match compiles the string to a regular expression.
+var match = regexp.MustCompile
+
+// literal compiles s into a literal regular expression, escaping any regexp
+// reserved characters.
+func literal(s string) *regexp.Regexp {
+	re := match(regexp.QuoteMeta(s))
+
+	if _, complete := re.LiteralPrefix(); !complete {
+		panic("must be a literal")
+	}
+
+	return re
+}
+
+// expression defines a full expression, where each regular expression must
+// follow the previous.
+func expression(res ...*regexp.Regexp) *regexp.Regexp {
+	var s string
+	for _, re := range res {
+		s += re.String()
+	}
+
+	return match(s)
+}
+
+// optional wraps the expression in a non-capturing group and makes the
+// production optional.
+func optional(res ...*regexp.Regexp) *regexp.Regexp {
+	return match(group(expression(res...)).String() + `?`)
+}
+
+// repeated wraps the regexp in a non-capturing group to get one or more
+// matches.
+func repeated(res ...*regexp.Regexp) *regexp.Regexp {
+	return match(group(expression(res...)).String() + `+`)
+}
+
+// group wraps the regexp in a non-capturing group.
+func group(res ...*regexp.Regexp) *regexp.Regexp {
+	return match(`(?:` + expression(res...).String() + `)`)
+}
+
+// capture wraps the expression in a capturing group.
+func capture(res ...*regexp.Regexp) *regexp.Regexp {
+	return match(`(` + expression(res...).String() + `)`)
+}
+
+// anchored anchors the regular expression by adding start and end delimiters.
+func anchored(res ...*regexp.Regexp) *regexp.Regexp {
+	return match(`^` + expression(res...).String() + `$`)
+}

vendor/github.com/docker/distribution/registry.go

@@ -0,0 +1,97 @@
+package distribution
+
+import (
+	"github.com/docker/distribution/context"
+	"github.com/docker/distribution/reference"
+)
+
+// Scope defines the set of items that match a namespace.
+type Scope interface {
+	// Contains returns true if the name belongs to the namespace.
+	Contains(name string) bool
+}
+
+type fullScope struct{}
+
+func (f fullScope) Contains(string) bool {
+	return true
+}
+
+// GlobalScope represents the full namespace scope which contains
+// all other scopes.
+var GlobalScope = Scope(fullScope{})
+
+// Namespace represents a collection of repositories, addressable by name.
+// Generally, a namespace is backed by a set of one or more services,
+// providing facilities such as registry access, trust, and indexing.
+type Namespace interface {
+	// Scope describes the names that can be used with this Namespace. The
+	// global namespace will have a scope that matches all names. The scope
+	// effectively provides an identity for the namespace.
+	Scope() Scope
+
+	// Repository should return a reference to the named repository. The
+	// registry may or may not have the repository but should always return a
+	// reference.
+	Repository(ctx context.Context, name reference.Named) (Repository, error)
+
+	// Repositories fills 'repos' with a lexigraphically sorted catalog of repositories
+	// up to the size of 'repos' and returns the value 'n' for the number of entries
+	// which were filled.  'last' contains an offset in the catalog, and 'err' will be
+	// set to io.EOF if there are no more entries to obtain.
+	Repositories(ctx context.Context, repos []string, last string) (n int, err error)
+
+	// Blobs returns a blob enumerator to access all blobs
+	Blobs() BlobEnumerator
+
+	// BlobStatter returns a BlobStatter to control
+	BlobStatter() BlobStatter
+}
+
+// RepositoryEnumerator describes an operation to enumerate repositories
+type RepositoryEnumerator interface {
+	Enumerate(ctx context.Context, ingester func(string) error) error
+}
+
+// ManifestServiceOption is a function argument for Manifest Service methods
+type ManifestServiceOption interface {
+	Apply(ManifestService) error
+}
+
+// WithTag allows a tag to be passed into Put
+func WithTag(tag string) ManifestServiceOption {
+	return WithTagOption{tag}
+}
+
+// WithTagOption holds a tag
+type WithTagOption struct{ Tag string }
+
+// Apply conforms to the ManifestServiceOption interface
+func (o WithTagOption) Apply(m ManifestService) error {
+	// no implementation
+	return nil
+}
+
+// Repository is a named collection of manifests and layers.
+type Repository interface {
+	// Named returns the name of the repository.
+	Named() reference.Named
+
+	// Manifests returns a reference to this repository's manifest service.
+	// with the supplied options applied.
+	Manifests(ctx context.Context, options ...ManifestServiceOption) (ManifestService, error)
+
+	// Blobs returns a reference to this repository's blob service.
+	Blobs(ctx context.Context) BlobStore
+
+	// TODO(stevvooe): The above BlobStore return can probably be relaxed to
+	// be a BlobService for use with clients. This will allow such
+	// implementations to avoid implementing ServeBlob.
+
+	// Tags returns a reference to this repositories tag service
+	Tags(ctx context.Context) TagService
+}
+
+// TODO(stevvooe): Must add close methods to all these. May want to change the
+// way instances are created to better reflect internal dependency
+// relationships.

vendor/github.com/docker/distribution/tags.go

@@ -0,0 +1,27 @@
+package distribution
+
+import (
+	"github.com/docker/distribution/context"
+)
+
+// TagService provides access to information about tagged objects.
+type TagService interface {
+	// Get retrieves the descriptor identified by the tag. Some
+	// implementations may differentiate between "trusted" tags and
+	// "untrusted" tags. If a tag is "untrusted", the mapping will be returned
+	// as an ErrTagUntrusted error, with the target descriptor.
+	Get(ctx context.Context, tag string) (Descriptor, error)
+
+	// Tag associates the tag with the provided descriptor, updating the
+	// current association, if needed.
+	Tag(ctx context.Context, tag string, desc Descriptor) error
+
+	// Untag removes the given tag association
+	Untag(ctx context.Context, tag string) error
+
+	// All returns the set of tags managed by this tag service
+	All(ctx context.Context) ([]string, error)
+
+	// Lookup returns the set of tags referencing the given digest.
+	Lookup(ctx context.Context, digest Descriptor) ([]string, error)
+}

vendor/github.com/docker/distribution/uuid/uuid.go

@@ -0,0 +1,126 @@
+// Package uuid provides simple UUID generation. Only version 4 style UUIDs
+// can be generated.
+//
+// Please see http://tools.ietf.org/html/rfc4122 for details on UUIDs.
+package uuid
+
+import (
+	"crypto/rand"
+	"fmt"
+	"io"
+	"os"
+	"syscall"
+	"time"
+)
+
+const (
+	// Bits is the number of bits in a UUID
+	Bits = 128
+
+	// Size is the number of bytes in a UUID
+	Size = Bits / 8
+
+	format = "%08x-%04x-%04x-%04x-%012x"
+)
+
+var (
+	// ErrUUIDInvalid indicates a parsed string is not a valid uuid.
+	ErrUUIDInvalid = fmt.Errorf("invalid uuid")
+
+	// Loggerf can be used to override the default logging destination. Such
+	// log messages in this library should be logged at warning or higher.
+	Loggerf = func(format string, args ...interface{}) {}
+)
+
+// UUID represents a UUID value. UUIDs can be compared and set to other values
+// and accessed by byte.
+type UUID [Size]byte
+
+// Generate creates a new, version 4 uuid.
+func Generate() (u UUID) {
+	const (
+		// ensures we backoff for less than 450ms total. Use the following to
+		// select new value, in units of 10ms:
+		// 	n*(n+1)/2 = d -> n^2 + n - 2d -> n = (sqrt(8d + 1) - 1)/2
+		maxretries = 9
+		backoff    = time.Millisecond * 10
+	)
+
+	var (
+		totalBackoff time.Duration
+		count        int
+		retries      int
+	)
+
+	for {
+		// This should never block but the read may fail. Because of this,
+		// we just try to read the random number generator until we get
+		// something. This is a very rare condition but may happen.
+		b := time.Duration(retries) * backoff
+		time.Sleep(b)
+		totalBackoff += b
+
+		n, err := io.ReadFull(rand.Reader, u[count:])
+		if err != nil {
+			if retryOnError(err) && retries < maxretries {
+				count += n
+				retries++
+				Loggerf("error generating version 4 uuid, retrying: %v", err)
+				continue
+			}
+
+			// Any other errors represent a system problem. What did someone
+			// do to /dev/urandom?
+			panic(fmt.Errorf("error reading random number generator, retried for %v: %v", totalBackoff.String(), err))
+		}
+
+		break
+	}
+
+	u[6] = (u[6] & 0x0f) | 0x40 // set version byte
+	u[8] = (u[8] & 0x3f) | 0x80 // set high order byte 0b10{8,9,a,b}
+
+	return u
+}
+
+// Parse attempts to extract a uuid from the string or returns an error.
+func Parse(s string) (u UUID, err error) {
+	if len(s) != 36 {
+		return UUID{}, ErrUUIDInvalid
+	}
+
+	// create stack addresses for each section of the uuid.
+	p := make([][]byte, 5)
+
+	if _, err := fmt.Sscanf(s, format, &p[0], &p[1], &p[2], &p[3], &p[4]); err != nil {
+		return u, err
+	}
+
+	copy(u[0:4], p[0])
+	copy(u[4:6], p[1])
+	copy(u[6:8], p[2])
+	copy(u[8:10], p[3])
+	copy(u[10:16], p[4])
+
+	return
+}
+
+func (u UUID) String() string {
+	return fmt.Sprintf(format, u[:4], u[4:6], u[6:8], u[8:10], u[10:])
+}
+
+// retryOnError tries to detect whether or not retrying would be fruitful.
+func retryOnError(err error) bool {
+	switch err := err.(type) {
+	case *os.PathError:
+		return retryOnError(err.Err) // unpack the target error
+	case syscall.Errno:
+		if err == syscall.EPERM {
+			// EPERM represents an entropy pool exhaustion, a condition under
+			// which we backoff and retry.
+			return true
+		}
+	}
+
+	return false
+}