add cli option to download all manifests

- Add `all-manifests` option to both `ctr content fetch` and `ctr
  images pull`. By default it is false.
- This option ties to `AppendDistributionSourceLabel` in client.

Signed-off-by: Yu Yi <yiyu@google.com>

cmd/ctr/commands/content/fetch.go

@@ -34,7 +34,7 @@ import (
 	"github.com/containerd/containerd/pkg/progress"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/remotes"
-	digest "github.com/opencontainers/go-digest"
+	"github.com/opencontainers/go-digest"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/urfave/cli"
 )
@@ -66,6 +66,10 @@ Most of this is experimental and there are few leaps to make this work.`,
 			Name:  "all-platforms",
 			Usage: "pull content from all platforms",
 		},
+		cli.BoolFlag{
+			Name:  "all-manifests",
+			Usage: "Pull manifests from all platforms and layers for a specific platform",
+		},
 	),
 	Action: func(clicontext *cli.Context) error {
 		var (
@@ -95,6 +99,8 @@ type FetchConfig struct {
 	Labels []string
 	// Platforms to fetch
 	Platforms []string
+	// Whether or not download all manifests
+	IsAllManifests bool
 }
 
 // NewFetchConfig returns the default FetchConfig from cli flags
@@ -117,6 +123,9 @@ func NewFetchConfig(ctx context.Context, clicontext *cli.Context) (*FetchConfig,
 		}
 		config.Platforms = p
 	}
+	if clicontext.Bool("all-manifests") {
+		config.IsAllManifests = clicontext.Bool("all-manifests")
+	}
 	return config, nil
 }
 
@@ -149,7 +158,10 @@ func Fetch(ctx context.Context, client *containerd.Client, ref string, config *F
 		containerd.WithResolver(config.Resolver),
 		containerd.WithImageHandler(h),
 		containerd.WithSchema1Conversion,
-		containerd.WithAppendDistributionSourceLabel(),
+	}
+
+	if config.IsAllManifests {
+		opts = append(opts, containerd.WithAppendDistributionSourceLabel())
 	}
 
 	for _, platform := range config.Platforms {

cmd/ctr/commands/images/pull.go

@@ -53,6 +53,10 @@ command. As part of this process, we do the following:
 			Name:  "all-platforms",
 			Usage: "pull content from all platforms",
 		},
+		cli.BoolFlag{
+			Name:  "all-manifests",
+			Usage: "Pull manifests from all platforms and layers for a specific platform",
+		},
 	),
 	Action: func(context *cli.Context) error {
 		var (
@@ -78,6 +82,10 @@ command. As part of this process, we do the following:
 		if err != nil {
 			return err
 		}
+		if context.Bool("all-manifests") {
+			config.IsAllManifests = context.Bool("all-manifests")
+		}
+
 		img, err := content.Fetch(ctx, client, ref, config)
 		if err != nil {
 			return err

pull.go

@@ -140,9 +140,14 @@ func (c *Client) fetch(ctx context.Context, rCtx *RemoteContext, ref string, lim
 		childrenHandler := images.ChildrenHandler(store)
 		// Set any children labels for that content
 		childrenHandler = images.SetChildrenLabels(store, childrenHandler)
-		// Filter manifests by platforms but allow to handle manifest
+		if rCtx.AppendDistributionSourceLabel {
-		// and configuration for not-target platforms
+			// Filter manifests by platforms but allow to handle manifest
-		childrenHandler = remotes.FilterManifestByPlatformHandler(childrenHandler, rCtx.PlatformMatcher)
+			// and configuration for not-target platforms
+			childrenHandler = remotes.FilterManifestByPlatformHandler(childrenHandler, rCtx.PlatformMatcher)
+		} else {
+			// Filter children by platforms if specified.
+			childrenHandler = images.FilterPlatforms(childrenHandler, rCtx.PlatformMatcher)
+		}
 		// Sort and limit manifests if a finite number is needed
 		if limit > 0 {
 			childrenHandler = images.LimitManifests(childrenHandler, rCtx.PlatformMatcher, limit)