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.vscode | ||
cmd/gomtree | ||
pkg/govis | ||
test | ||
testdata | ||
vendor | ||
xattr | ||
.gitignore | ||
.travis.yml | ||
check.go | ||
check_test.go | ||
cksum.go | ||
cksum_test.go | ||
compare.go | ||
compare_test.go | ||
creator.go | ||
entry.go | ||
fseval.go | ||
fseval_test.go | ||
glide.lock | ||
glide.yaml | ||
hierarchy.go | ||
hierarchy_test.go | ||
keywordfunc.go | ||
keywordfuncs_bsd.go | ||
keywordfuncs_linux.go | ||
keywordfuncs_unsupported.go | ||
keywords.go | ||
keywords_linux_test.go | ||
keywords_test.go | ||
lchtimes_unix.go | ||
lchtimes_unsupported.go | ||
LICENSE | ||
lookup_new.go | ||
lookup_old.go | ||
Makefile | ||
mtree_test.go | ||
parse.go | ||
README.md | ||
releases.md | ||
stat_unix.go | ||
stat_windows.go | ||
tar.go | ||
tar_test.go | ||
update.go | ||
update_linux_test.go | ||
update_test.go | ||
updatefuncs.go | ||
updatefuncs_linux.go | ||
updatefuncs_unsupported.go | ||
version.go | ||
walk.go | ||
walk_test.go |
go-mtree
mtree
is a filesystem hierarchy validation tooling and format.
This is a library and simple cli tool for mtree(8) support.
While the traditional mtree
cli utility is primarily on BSDs (FreeBSD,
openBSD, etc), even broader support for the mtree
specification format is
provided with libarchive (libarchive-formats(5)).
There is also an mtree port for Linux though it is not widely packaged for Linux distributions.
Format
The format of hierarchy specification is consistent with the # mtree v2.0
format. Both the BSD mtree
and libarchive ought to be interoperable with it
with only one definite caveat. On Linux, extended attributes (xattr
) on
files are often a critical aspect of the file, holding ACLs, capabilities, etc.
While FreeBSD filesystem do support extattr
, this feature has not made its
way into their mtree
.
This implementation of mtree supports a few non-upstream "keyword"s, such as:
xattr
and tar_time
. If you include these keywords, the FreeBSD mtree
will fail, as they are unknown keywords to that implementation.
To have go-mtree
produce specifications that will be
strictly compatible with the BSD mtree
, use the -bsd-keywords
flag when
creating a manifest. This will make sure that only the keywords supported by
BSD mtree
are used in the program.
Typical form
With the standard keywords, plus say sha256digest
, the hierarchy
specification looks like:
# .
/set type=file nlink=1 mode=0664 uid=1000 gid=100
. size=4096 type=dir mode=0755 nlink=6 time=1459370393.273231538
LICENSE size=1502 mode=0644 time=1458851690.0 sha256digest=ef4e53d83096be56dc38dbf9bc8ba9e3068bec1ec37c179033d1e8f99a1c2a95
README.md size=2820 mode=0644 time=1459370256.316148361 sha256digest=d9b955134d99f84b17c0a711ce507515cc93cd7080a9dcd50400e3d993d876ac
[...]
See the directory presently in, and the files present. Along with each
path, is provided the keywords and the unique values for each path. Any common
keyword and values are established in the /set
command.
Extended attributes form
# .
/set type=file nlink=1 mode=0664 uid=1000 gid=1000
. size=4096 type=dir mode=0775 nlink=6 time=1459370191.11179595 xattr.security.selinux=dW5jb25maW5lZF91Om9iamVjdF9yOnVzZXJfaG9tZV90OnMwAA==
LICENSE size=1502 time=1458851690.583562292 xattr.security.selinux=dW5jb25maW5lZF91Om9iamVjdF9yOnVzZXJfaG9tZV90OnMwAA==
README.md size=2366 mode=0644 time=1459369604.0 xattr.security.selinux=dW5jb25maW5lZF91Om9iamVjdF9yOnVzZXJfaG9tZV90OnMwAA==
[...]
See the keyword prefixed with xattr.
followed by the extended attribute's
namespace and keyword. This setup is consistent for use with Linux extended
attributes as well as FreeBSD extended attributes.
Since extended attributes are an unordered hashmap, this approach allows for
checking each <namespace>.<key>
individually.
The value is the base64 encoded of the value of the particular extended attribute. Since the values themselves could be raw bytes, this approach avoids issues with encoding.
Tar form
# .
/set type=file mode=0664 uid=1000 gid=1000
. type=dir mode=0775 tar_time=1468430408.000000000
# samedir
samedir type=dir mode=0775 tar_time=1468000972.000000000
file2 size=0 tar_time=1467999782.000000000
file1 size=0 tar_time=1467999781.000000000
[...]
While go-mtree
serves mainly as a library for upstream mtree
support,
go-mtree
is also compatible with tar archives (which is not an upstream feature).
This means that we can now create and validate a manifest by specifying a tar file.
More interestingly, this also means that we can create a manifest from an archive, and then
validate this manifest against a filesystem hierarchy that's on disk, and vice versa.
Notice that for the output of creating a validation manifest from a tar file, the default behavior
for evaluating a notion of time is to use the tar_time
keyword. In the
"filesystem hierarchy" format of mtree, time
is being evaluated with
nanosecond precision. However, GNU tar truncates a file's modification time
to 1-second precision. That is, if a file's full modification time is
123456789.123456789, the "tar time" equivalent would be 123456789.000000000.
This way, if you validate a manifest created using a tar file against an
actual root directory, there will be no complaints from go-mtree
so long as the
1-second precision time of a file in the root directory is the same.
Usage
To use the Go programming language library, see the docs.
To use the command line tool, first build it, then the following.
Create a manifest
This will also include the sha512 digest of the files.
gomtree -c -K sha512digest -p . > /tmp/root.mtree
With a tar file:
gomtree -c -K sha512digest -T sometarfile.tar > /tmp/tar.mtree
Validate a manifest
gomtree -p . -f /tmp/root.mtree
With a tar file:
gomtree -T sometarfile.tar -f /tmp/root.mtree
See the supported keywords
gomtree -list-keywords
Available keywords:
uname
sha1
sha1digest
sha256digest
xattrs (not upstream)
link (default)
nlink (default)
md5digest
rmd160digest
mode (default)
cksum
md5
rmd160
type (default)
time (default)
uid (default)
gid (default)
sha256
sha384
sha512
xattr (not upstream)
tar_time (not upstream)
size (default)
ripemd160digest
sha384digest
sha512digest
Building
Either:
go get github.com/vbatts/go-mtree/cmd/gomtree
or
git clone git://github.com/vbatts/go-mtree.git $GOPATH/src/github.com/vbatts/go-mtree
cd $GOPATH/src/github.com/vbatts/go-mtree
go build ./cmd/gomtree
Testing
On Linux:
cd $GOPATH/src/github.com/vbatts/go-mtree
make
On FreeBSD:
cd $GOPATH/src/github.com/vbatts/go-mtree
gmake