containerd/cmd/dist/rootfs.go
Derek McGowan 3ae69c43d8
Add diff service implementation
Add snapshot subcommand to ctr for creating diffs of RW layers.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>
2017-05-16 13:48:53 -07:00

121 lines
2.9 KiB
Go

package main
import (
"fmt"
"os"
"strings"
diffapi "github.com/containerd/containerd/api/services/diff"
snapshotapi "github.com/containerd/containerd/api/services/snapshot"
"github.com/containerd/containerd/images"
"github.com/containerd/containerd/log"
"github.com/containerd/containerd/rootfs"
diffservice "github.com/containerd/containerd/services/diff"
snapshotservice "github.com/containerd/containerd/services/snapshot"
digest "github.com/opencontainers/go-digest"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/urfave/cli"
)
var rootfsCommand = cli.Command{
Name: "rootfs",
Usage: "rootfs setups a rootfs",
Subcommands: []cli.Command{
rootfsUnpackCommand,
rootfsPrepareCommand,
},
}
var rootfsUnpackCommand = cli.Command{
Name: "unpack",
Usage: "unpack applies layers from a manifest to a snapshot",
ArgsUsage: "[flags] <digest>",
Flags: []cli.Flag{},
Action: func(clicontext *cli.Context) error {
ctx, cancel := appContext()
defer cancel()
dgst, err := digest.Parse(clicontext.Args().First())
if err != nil {
return err
}
log.G(ctx).Infof("unpacking layers from manifest %s", dgst.String())
cs, err := resolveContentStore(clicontext)
if err != nil {
return err
}
image := images.Image{
Target: ocispec.Descriptor{
MediaType: ocispec.MediaTypeImageManifest,
Digest: dgst,
},
}
layers, err := getImageLayers(ctx, image, cs)
if err != nil {
log.G(ctx).WithError(err).Fatal("Failed to get rootfs layers")
}
conn, err := connectGRPC(clicontext)
if err != nil {
log.G(ctx).Fatal(err)
}
snapshotter := snapshotservice.NewSnapshotterFromClient(snapshotapi.NewSnapshotClient(conn))
applier := diffservice.NewDiffServiceFromClient(diffapi.NewDiffClient(conn))
chainID, err := rootfs.ApplyLayers(ctx, layers, snapshotter, applier)
if err != nil {
return err
}
log.G(ctx).Infof("chain ID: %s", chainID.String())
return nil
},
}
var rootfsPrepareCommand = cli.Command{
Name: "prepare",
Usage: "prepare gets mount commands for digest",
ArgsUsage: "[flags] <digest> <target>",
Flags: []cli.Flag{},
Action: func(clicontext *cli.Context) error {
ctx, cancel := appContext()
defer cancel()
if clicontext.NArg() != 2 {
return cli.ShowSubcommandHelp(clicontext)
}
dgst, err := digest.Parse(clicontext.Args().Get(0))
if err != nil {
return err
}
target := clicontext.Args().Get(1)
log.G(ctx).Infof("preparing mounts %s", dgst.String())
conn, err := connectGRPC(clicontext)
if err != nil {
return err
}
snapshotter := snapshotservice.NewSnapshotterFromClient(snapshotapi.NewSnapshotClient(conn))
mounts, err := snapshotter.Prepare(ctx, target, dgst.String())
if err != nil {
return err
}
for _, m := range mounts {
fmt.Fprintf(os.Stdout, "mount -t %s %s %s -o %s\n", m.Type, m.Source, target, strings.Join(m.Options, ","))
}
return nil
},
}