Add option to pull all metadata

Add flags to pull and fetch to grab all metadata.
Add fetch option to pull only metadata.

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

cmd/ctr/commands/content/fetch.go

@@ -67,8 +67,12 @@ Most of this is experimental and there are few leaps to make this work.`,
 			Usage: "pull content from all platforms",
 		},
 		cli.BoolFlag{
-			Name:  "all-manifests",
-			Usage: "Pull manifests from all platforms and layers for a specific platform",
+			Name:  "all-metadata",
+			Usage: "Pull metadata for all platforms",
+		},
+		cli.BoolFlag{
+			Name:  "metadata-only",
+			Usage: "Pull all metadata including manifests and configs",
 		},
 	),
 	Action: func(clicontext *cli.Context) error {
@@ -84,6 +88,7 @@ Most of this is experimental and there are few leaps to make this work.`,
 		if err != nil {
 			return err
 		}
+
 		_, err = Fetch(ctx, client, ref, config)
 		return err
 	},
@@ -97,10 +102,12 @@ type FetchConfig struct {
 	ProgressOutput io.Writer
 	// Labels to set on the content
 	Labels []string
+	// PlatformMatcher matches platforms, supersedes Platforms
+	PlatformMatcher platforms.MatchComparer
 	// Platforms to fetch
 	Platforms []string
-	// Whether or not download all manifests
-	IsAllManifests bool
+	// Whether or not download all metadata
+	AllMetadata bool
 }
 
 // NewFetchConfig returns the default FetchConfig from cli flags
@@ -124,7 +131,13 @@ func NewFetchConfig(ctx context.Context, clicontext *cli.Context) (*FetchConfig,
 		config.Platforms = p
 	}
 
-	config.IsAllManifests = clicontext.Bool("all-manifests")
+	if clicontext.Bool("metadata-only") {
+		config.AllMetadata = true
+		// Any with an empty set is None
+		config.PlatformMatcher = platforms.Any()
+	} else if clicontext.Bool("all-metadata") {
+		config.AllMetadata = true
+	}
 
 	return config, nil
 }
@@ -160,12 +173,16 @@ func Fetch(ctx context.Context, client *containerd.Client, ref string, config *F
 		containerd.WithSchema1Conversion,
 	}
 
-	if config.IsAllManifests {
-		opts = append(opts, containerd.WithAppendDistributionSourceLabel())
+	if config.AllMetadata {
+		opts = append(opts, containerd.WithAllMetadata())
 	}
 
-	for _, platform := range config.Platforms {
-		opts = append(opts, containerd.WithPlatform(platform))
+	if config.PlatformMatcher != nil {
+		opts = append(opts, containerd.WithPlatformMatcher(config.PlatformMatcher))
+	} else {
+		for _, platform := range config.Platforms {
+			opts = append(opts, containerd.WithPlatform(platform))
+		}
 	}
 
 	img, err := client.Fetch(pctx, ref, opts...)