Merge pull request #743 from fahedouch/fix-inspector

enhance inspect

Author: AkihiroSuda

cmd/nerdctl/container_inspect.go

@@ -81,6 +81,7 @@ func containerInspectAction(cmd *cobra.Command, args []string) error {
 	if len(errs) > 0 {
 		return fmt.Errorf("%d errors: %v", len(errs), errs)
 	}
+
 	return formatSlice(cmd, f.entries)
 }
 

cmd/nerdctl/fmtutil.go

@@ -75,7 +75,12 @@ func formatSlice(cmd *cobra.Command, x []interface{}) error {
 		for _, f := range x {
 			var b bytes.Buffer
 			if err := tmpl.Execute(&b, f); err != nil {
-				return err
+				if _, ok := err.(template.ExecError); ok {
+					// FallBack to Raw Format
+					if err = tryRawFormat(&b, f, tmpl); err != nil {
+						return err
+					}
+				}
 			}
 			if _, err = fmt.Fprintf(cmd.OutOrStdout(), b.String()+"\n"); err != nil {
 				return err
@@ -85,6 +90,29 @@ func formatSlice(cmd *cobra.Command, x []interface{}) error {
 	return nil
 }
 
+func tryRawFormat(b *bytes.Buffer, f interface{}, tmpl *template.Template) error {
+	m, err := json.MarshalIndent(f, "", "    ")
+	if err != nil {
+		return err
+	}
+
+	var raw interface{}
+	rdr := bytes.NewReader(m)
+	dec := json.NewDecoder(rdr)
+	dec.UseNumber()
+
+	if rawErr := dec.Decode(&raw); rawErr != nil {
+		return fmt.Errorf("unable to read inspect data: %v", rawErr)
+	}
+
+	tmplMissingKey := tmpl.Option("missingkey=error")
+	if rawErr := tmplMissingKey.Execute(b, raw); rawErr != nil {
+		return fmt.Errorf("Template parsing error: %v", rawErr)
+	}
+
+	return nil
+}
+
 // parseTemplate wraps github.com/docker/cli/templates.Parse() to allow `json` as an alias of `{{json .}}`.
 // parseTemplate can be removed when https://github.com/docker/cli/pull/3355 gets merged and tagged (Docker 22.XX).
 func parseTemplate(format string) (*template.Template, error) {

cmd/nerdctl/image_inspect.go

@@ -128,6 +128,7 @@ func imageInspectActionWithPlatform(cmd *cobra.Command, args []string, platform
 	if len(errs) > 0 {
 		return fmt.Errorf("%d errors: %v", len(errs), errs)
 	}
+
 	return formatSlice(cmd, f.entries)
 }
 

cmd/nerdctl/image_inspect_test.go

@@ -33,3 +33,14 @@ func TestImageInspectContainsSomeStuff(t *testing.T) {
 	assert.Assert(base.T, inspect.RootFS.Type != "")
 	assert.Assert(base.T, inspect.Architecture != "")
 }
+
+func TestImageInspectWithFormat(t *testing.T) {
+	base := testutil.NewBase(t)
+
+	base.Cmd("pull", testutil.CommonImage).AssertOK()
+	// test RawFormat support
+	base.Cmd("image", "inspect", testutil.CommonImage, "--format", "{{.Id}}").AssertOK()
+
+	// test typedFormat support
+	base.Cmd("image", "inspect", testutil.CommonImage, "--format", "{{.ID}}").AssertOK()
+}

cmd/nerdctl/inspect.go

@@ -74,6 +74,7 @@ func inspectAction(cmd *cobra.Command, args []string) error {
 		},
 	}
 
+	var errs []error
 	for _, req := range args {
 		ni, err := imagewalker.Walk(ctx, req)
 		if err != nil {
@@ -93,16 +94,20 @@ func inspectAction(cmd *cobra.Command, args []string) error {
 			return fmt.Errorf("no such object %s", req)
 		}
 		if ni != 0 {
-			if err := imageInspectActionWithPlatform(cmd, args, ""); err != nil {
-				return err
+			if err := imageInspectActionWithPlatform(cmd, []string{req}, ""); err != nil {
+				errs = append(errs, err)
 			}
 		} else {
-			if err := containerInspectAction(cmd, args); err != nil {
-				return err
+			if err := containerInspectAction(cmd, []string{req}); err != nil {
+				errs = append(errs, err)
 			}
 		}
 	}
 
+	if len(errs) > 0 {
+		return fmt.Errorf("%d errors: %v", len(errs), errs)
+	}
+
 	return nil
 }