containerd/content/content.go

60 lines
1 KiB
Go
Raw Normal View History

package content
import (
"context"
"io"
"sync"
dist: expand functionality of the dist tool With this change, we add the following commands to the dist tool: - `ingest`: verify and accept content into storage - `active`: display active ingest processes - `list`: list content in storage - `path`: provide a path to a blob by digest - `delete`: remove a piece of content from storage We demonstrate the utility with the following shell pipeline: ``` $ ./dist fetch docker.io/library/redis latest mediatype:application/vnd.docker.distribution.manifest.v2+json | \ jq -r '.layers[] | "./dist fetch docker.io/library/redis "+.digest + "| ./dist ingest --expected-digest "+.digest+" --expected-size "+(.size | tostring) +" docker.io/library/redis@"+.digest' | xargs -I{} -P10 -n1 sh -c "{}" ``` The above fetches a manifest, pipes it to jq, which assembles a shell pipeline to ingest each layer into the content store. Because the transactions are keyed by their digest, concurrent downloads and downloads of repeated content are ignored. Each process is then executed parallel using xargs. Put shortly, this is a parallel layer download. In a separate shell session, could monitor the active downloads with the following: ``` $ watch -n0.2 ./dist active ``` For now, the content is downloaded into `.content` in the current working directory. To watch the contents of this directory, you can use the following: ``` $ watch -n0.2 tree .content ``` This will help to understand what is going on internally. To get access to the layers, you can use the path command: ``` $./dist path sha256:010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa sha256:010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa /home/sjd/go/src/github.com/docker/containerd/.content/blobs/sha256/010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa ``` When you are done, you can clear out the content with the classic xargs pipeline: ``` $ ./dist list -q | xargs ./dist delete ``` Note that this is mostly a POC. Things like failed downloads and abandoned download cleanup aren't quite handled. We'll probably make adjustments around how content store transactions are handled to address this. From here, we'll build out full image pull and create tooling to get runtime bundles from the fetched content. Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-01-26 22:08:56 +00:00
"time"
"github.com/opencontainers/go-digest"
"github.com/pkg/errors"
)
var (
errNotFound = errors.New("content: not found")
errExists = errors.New("content: exists")
BufPool = sync.Pool{
New: func() interface{} {
return make([]byte, 1<<20)
},
}
)
type Info struct {
Digest digest.Digest
Size int64
CommittedAt time.Time
}
type Provider interface {
Reader(ctx context.Context, dgst digest.Digest) (io.ReadCloser, error)
}
type Status struct {
Ref string
Offset int64
Total int64
StartedAt time.Time
UpdatedAt time.Time
dist: expand functionality of the dist tool With this change, we add the following commands to the dist tool: - `ingest`: verify and accept content into storage - `active`: display active ingest processes - `list`: list content in storage - `path`: provide a path to a blob by digest - `delete`: remove a piece of content from storage We demonstrate the utility with the following shell pipeline: ``` $ ./dist fetch docker.io/library/redis latest mediatype:application/vnd.docker.distribution.manifest.v2+json | \ jq -r '.layers[] | "./dist fetch docker.io/library/redis "+.digest + "| ./dist ingest --expected-digest "+.digest+" --expected-size "+(.size | tostring) +" docker.io/library/redis@"+.digest' | xargs -I{} -P10 -n1 sh -c "{}" ``` The above fetches a manifest, pipes it to jq, which assembles a shell pipeline to ingest each layer into the content store. Because the transactions are keyed by their digest, concurrent downloads and downloads of repeated content are ignored. Each process is then executed parallel using xargs. Put shortly, this is a parallel layer download. In a separate shell session, could monitor the active downloads with the following: ``` $ watch -n0.2 ./dist active ``` For now, the content is downloaded into `.content` in the current working directory. To watch the contents of this directory, you can use the following: ``` $ watch -n0.2 tree .content ``` This will help to understand what is going on internally. To get access to the layers, you can use the path command: ``` $./dist path sha256:010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa sha256:010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa /home/sjd/go/src/github.com/docker/containerd/.content/blobs/sha256/010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa ``` When you are done, you can clear out the content with the classic xargs pipeline: ``` $ ./dist list -q | xargs ./dist delete ``` Note that this is mostly a POC. Things like failed downloads and abandoned download cleanup aren't quite handled. We'll probably make adjustments around how content store transactions are handled to address this. From here, we'll build out full image pull and create tooling to get runtime bundles from the fetched content. Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-01-26 22:08:56 +00:00
}
type Writer interface {
io.WriteCloser
Status() (Status, error)
Digest() digest.Digest
Commit(size int64, expected digest.Digest) error
dist: expand functionality of the dist tool With this change, we add the following commands to the dist tool: - `ingest`: verify and accept content into storage - `active`: display active ingest processes - `list`: list content in storage - `path`: provide a path to a blob by digest - `delete`: remove a piece of content from storage We demonstrate the utility with the following shell pipeline: ``` $ ./dist fetch docker.io/library/redis latest mediatype:application/vnd.docker.distribution.manifest.v2+json | \ jq -r '.layers[] | "./dist fetch docker.io/library/redis "+.digest + "| ./dist ingest --expected-digest "+.digest+" --expected-size "+(.size | tostring) +" docker.io/library/redis@"+.digest' | xargs -I{} -P10 -n1 sh -c "{}" ``` The above fetches a manifest, pipes it to jq, which assembles a shell pipeline to ingest each layer into the content store. Because the transactions are keyed by their digest, concurrent downloads and downloads of repeated content are ignored. Each process is then executed parallel using xargs. Put shortly, this is a parallel layer download. In a separate shell session, could monitor the active downloads with the following: ``` $ watch -n0.2 ./dist active ``` For now, the content is downloaded into `.content` in the current working directory. To watch the contents of this directory, you can use the following: ``` $ watch -n0.2 tree .content ``` This will help to understand what is going on internally. To get access to the layers, you can use the path command: ``` $./dist path sha256:010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa sha256:010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa /home/sjd/go/src/github.com/docker/containerd/.content/blobs/sha256/010c454d55e53059beaba4044116ea4636f8dd8181e975d893931c7e7204fffa ``` When you are done, you can clear out the content with the classic xargs pipeline: ``` $ ./dist list -q | xargs ./dist delete ``` Note that this is mostly a POC. Things like failed downloads and abandoned download cleanup aren't quite handled. We'll probably make adjustments around how content store transactions are handled to address this. From here, we'll build out full image pull and create tooling to get runtime bundles from the fetched content. Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-01-26 22:08:56 +00:00
}
type Ingester interface {
Writer(ctx context.Context, ref string, size int64, expected digest.Digest) (Writer, error)
}
func IsNotFound(err error) bool {
return errors.Cause(err) == errNotFound
}
func IsExists(err error) bool {
return errors.Cause(err) == errExists
}