Merge pull request #4848 from katiewasnothere/ctr_image_chainid

Add a new flag to ctr "images pull" to print the image's chainID

cmd/ctr/commands/images/pull.go

@@ -25,6 +25,7 @@ import (
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/platforms"
+	"github.com/opencontainers/image-spec/identity"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
@@ -57,6 +58,10 @@ command. As part of this process, we do the following:
 			Name:  "all-metadata",
 			Usage: "Pull metadata for all platforms",
 		},
+		cli.BoolFlag{
+			Name:  "print-chainid",
+			Usage: "Print the resulting image's chain ID",
+		},
 	),
 	Action: func(context *cli.Context) error {
 		var (
@@ -118,6 +123,14 @@ command. As part of this process, we do the following:
 			if err != nil {
 				return err
 			}
+			if context.Bool("print-chainid") {
+				diffIDs, err := i.RootFS(ctx)
+				if err != nil {
+					return err
+				}
+				chainID := identity.ChainID(diffIDs).String()
+				fmt.Printf("image chain ID: %s\n", chainID)
+			}
 		}
 
 		fmt.Println("done")

cmd/ctr/commands/snapshots/snapshots.go

@@ -280,6 +280,10 @@ var prepareCommand = cli.Command{
 			Name:  "target, t",
 			Usage: "mount target path, will print mount, if provided",
 		},
+		cli.BoolFlag{
+			Name:  "mounts",
+			Usage: "Print out snapshot mounts as JSON",
+		},
 	},
 	Action: func(context *cli.Context) error {
 		if narg := context.NArg(); narg < 1 || narg > 2 {
@@ -310,6 +314,10 @@ var prepareCommand = cli.Command{
 			printMounts(target, mounts)
 		}
 
+		if context.Bool("mounts") {
+			commands.PrintAsJSON(mounts)
+		}
+
 		return nil
 	},
 }
@@ -323,6 +331,10 @@ var viewCommand = cli.Command{
 			Name:  "target, t",
 			Usage: "mount target path, will print mount, if provided",
 		},
+		cli.BoolFlag{
+			Name:  "mounts",
+			Usage: "Print out snapshot mounts as JSON",
+		},
 	},
 	Action: func(context *cli.Context) error {
 		if narg := context.NArg(); narg < 1 || narg > 2 {
@@ -349,6 +361,10 @@ var viewCommand = cli.Command{
 			printMounts(target, mounts)
 		}
 
+		if context.Bool("mounts") {
+			commands.PrintAsJSON(mounts)
+		}
+
 		return nil
 	},
 }