feat: Add snapshotter label to the new snapshot for container.

BigVan · BigVan · commit bda7b58666b9 · 2021-06-28T20:08:01.000+08:00
add '--snapshotter-labels' in ctr run and ctr c create which can pass labels to snappshotter on preparing new snapshot. Pass command label to snapshotter can help it determine which kind of writable snapshots should be provide. For some snapshotter, such as overlaybd: ( https://github.com/alibaba/accelerated-container-image ), it can provide 2 kind of writable snapshot (overlayfs dir or blockdevice) by command label values. Signed-off-by: Yifan Yuan <tuji.yyf@alibaba-inc.com>
diff --git a/cmd/ctr/commands/commands.go b/cmd/ctr/commands/commands.go
@@ -37,6 +37,12 @@ var (
 		},
 	}
 
+	// SnapshotterLabels are cli flags specifying labels which will be add to the new snapshot for container.
+	SnapshotterLabels = cli.StringSliceFlag{
+		Name:  "snapshotter-label",
+		Usage: "labels added to the new snapshot for this container.",
+	}
+
 	// LabelFlag is a cli flag specifying labels
 	LabelFlag = cli.StringSliceFlag{
 		Name:  "label",
diff --git a/cmd/ctr/commands/containers/containers.go b/cmd/ctr/commands/containers/containers.go
@@ -55,7 +55,7 @@ var createCommand = cli.Command{
 	Name:      "create",
 	Usage:     "create container",
 	ArgsUsage: "[flags] Image|RootFS CONTAINER [COMMAND] [ARG...]",
-	Flags:     append(commands.SnapshotterFlags, commands.ContainerFlags...),
+	Flags:     append(append(commands.SnapshotterFlags, []cli.Flag{commands.SnapshotterLabels}...), commands.ContainerFlags...),
 	Action: func(context *cli.Context) error {
 		var (
 			id     string
diff --git a/cmd/ctr/commands/run/run.go b/cmd/ctr/commands/run/run.go
@@ -122,7 +122,9 @@ var Command = cli.Command{
 			Name:  "platform",
 			Usage: "run image for specific platform",
 		},
-	}, append(platformRunFlags, append(commands.SnapshotterFlags, commands.ContainerFlags...)...)...),
+	}, append(platformRunFlags,
+		append(append(commands.SnapshotterFlags, []cli.Flag{commands.SnapshotterLabels}...),
+			commands.ContainerFlags...)...)...),
 	Action: func(context *cli.Context) error {
 		var (
 			err error
diff --git a/cmd/ctr/commands/run/run_unix.go b/cmd/ctr/commands/run/run_unix.go
@@ -35,6 +35,7 @@ import (
 	runtimeoptions "github.com/containerd/containerd/pkg/runtimeoptions/v1"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/runtime/v2/runc/options"
+	"github.com/containerd/containerd/snapshots"
 	"github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -171,7 +172,10 @@ func NewContainer(ctx gocontext.Context, client *containerd.Client, context *cli
 				// Even when "read-only" is set, we don't use KindView snapshot here. (#1495)
 				// We pass writable snapshot to the OCI runtime, and the runtime remounts it as read-only,
 				// after creating some mount points on demand.
-				cOpts = append(cOpts, containerd.WithNewSnapshot(id, image))
+				// For some snapshotter, such as overlaybd, it can provide 2 kind of writable snapshot(overlayfs dir or block-device)
+				// by command label values.
+				cOpts = append(cOpts, containerd.WithNewSnapshot(id, image,
+					snapshots.WithLabels(commands.LabelArgs(context.StringSlice("snapshotter-label")))))
 			}
 			cOpts = append(cOpts, containerd.WithImageStopSignal(image, "SIGTERM"))
 		}
