imagetools: implement inspect for manifest list

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

util/imagetools/printers.go

@@ -0,0 +1,74 @@
+package imagetools
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"text/tabwriter"
+
+	"github.com/containerd/containerd/platforms"
+	"github.com/docker/distribution/reference"
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+func PrintManifestList(dt []byte, desc ocispec.Descriptor, refstr string, out io.Writer) error {
+	ref, err := parseRef(refstr)
+	if err != nil {
+		return err
+	}
+
+	var mfst ocispec.Index
+	if err := json.Unmarshal(dt, &mfst); err != nil {
+		return err
+	}
+
+	w := tabwriter.NewWriter(out, 0, 0, 1, ' ', 0)
+
+	fmt.Fprintf(w, "Name:\t%s\n", ref.String())
+	fmt.Fprintf(w, "MediaType:\t%s\n", desc.MediaType)
+	fmt.Fprintf(w, "Digest:\t%s\n", desc.Digest)
+	fmt.Fprintf(w, "\t\n")
+
+	fmt.Fprintf(w, "Manifests:\t\n")
+	w.Flush()
+
+	pfx := "  "
+
+	w = tabwriter.NewWriter(os.Stdout, 0, 0, 1, ' ', 0)
+	for i, m := range mfst.Manifests {
+		if i != 0 {
+			fmt.Fprintf(w, "\t\n")
+		}
+		cr, err := reference.WithDigest(ref, m.Digest)
+		if err != nil {
+			return err
+		}
+		fmt.Fprintf(w, "%sName:\t%s\n", pfx, cr.String())
+		fmt.Fprintf(w, "%sMediaType:\t%s\n", pfx, m.MediaType)
+		if p := m.Platform; p != nil {
+			fmt.Fprintf(w, "%sPlatform:\t%s\n", pfx, platforms.Format(*p))
+			if p.OSVersion != "" {
+				fmt.Fprintf(w, "%sOSVersion:\t%s\n", pfx, p.OSVersion)
+			}
+			if len(p.OSFeatures) > 0 {
+				fmt.Fprintf(w, "%sOSFeatures:\t%s\n", pfx, strings.Join(p.OSFeatures, ", "))
+			}
+			if len(m.URLs) > 0 {
+				fmt.Fprintf(w, "%sURLs:\t%s\n", pfx, strings.Join(m.URLs, ", "))
+			}
+			if len(m.Annotations) > 0 {
+				w.Flush()
+				w2 := tabwriter.NewWriter(os.Stdout, 0, 0, 1, ' ', 0)
+				pfx2 := pfx + "  "
+				for k, v := range m.Annotations {
+					fmt.Fprintf(w2, "%s%s:\t%s\n", pfx2, k, v)
+				}
+				w2.Flush()
+			}
+		}
+	}
+
+	return w.Flush()
+}