
Add snapshot subcommand to ctr for creating diffs of RW layers. Signed-off-by: Derek McGowan <derek@mcgstyle.net>
121 lines
2.9 KiB
Go
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
|
|
},
|
|
}
|