fix struct fields with json tags

Signed-off-by: Billy Zha <[email protected]>

cmd/oras/internal/display/handler.go

@@ -23,6 +23,7 @@ import (
 	"oras.land/oras/cmd/oras/internal/display/metadata/json"
 	"oras.land/oras/cmd/oras/internal/display/metadata/template"
 	"oras.land/oras/cmd/oras/internal/display/metadata/text"
+	"oras.land/oras/cmd/oras/internal/display/raw"
 	"oras.land/oras/cmd/oras/internal/display/status"
 )
 
@@ -75,6 +76,19 @@ func NewAttachHandler(format string, tty *os.File, out io.Writer, verbose bool)
 }
 
 // NewManifestFetchHandler returns a manifest fetch handler.
-func NewManifestFetchHandler(out io.Writer, format string) metadata.ManifestFetchHandler {
-	return template.NewManifestFetchHandler(out, format)
+func NewManifestFetchHandler(out io.Writer, outputPath string, format string, pretty bool) (metadata.ManifestFetchHandler, raw.ManifestFetchHandler) {
+	var metadataHandler metadata.ManifestFetchHandler
+	var rawContentHandler raw.ManifestFetchHandler
+	switch format {
+	case "raw":
+		metadataHandler = metadata.NewDiscardHandler()
+		rawContentHandler = raw.NewManifestFetchHandler(out, pretty)
+	case "json":
+		metadataHandler = json.NewManifestFetchHandler(out)
+		rawContentHandler = raw.NewDiscardHandler()
+	default:
+		metadataHandler = template.NewManifestFetchHandler(out, format)
+		rawContentHandler = raw.NewDiscardHandler()
+	}
+	return metadataHandler, rawContentHandler
 }

cmd/oras/internal/display/metadata/discard.go

@@ -0,0 +1,28 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package metadata
+
+import ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+
+type discard struct{}
+
+// NewDiscardHandler creates a new handler that discards output for all events.
+func NewDiscardHandler() ManifestFetchHandler {
+	return discard{}
+}
+
+// OnFetched implements ManifestFetchHandler.
+func (discard) OnFetched([]byte, ocispec.Descriptor) error { return nil }

cmd/oras/internal/display/metadata/interface.go

@@ -33,5 +33,6 @@ type AttachHandler interface {
 
 // ManifestFetchHandler handles metadata output for manifest fetch events.
 type ManifestFetchHandler interface {
-	OnFetched(manifest ocispec.Manifest) error
+	// OnFetched is called after the manifest content is fetched.
+	OnFetched([]byte, ocispec.Descriptor) error
 }

cmd/oras/internal/display/metadata/json/manifest_fetch.go

@@ -0,0 +1,54 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package json
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"reflect"
+
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+	"oras.land/oras/cmd/oras/internal/display/metadata"
+	"oras.land/oras/cmd/oras/internal/display/metadata/model"
+	"oras.land/oras/internal/docker"
+)
+
+// ManifestFetchHandler handles JSON metadata output for manifest fetch events.
+type ManifestFetchHandler struct {
+	out io.Writer
+}
+
+// NewManifestFetchHandler creates a new handler for manifest fetch events.
+func NewManifestFetchHandler(out io.Writer) metadata.ManifestFetchHandler {
+	return &ManifestFetchHandler{
+		out: out,
+	}
+}
+
+// OnFetched is called after the manifest fetch is completed.
+func (h *ManifestFetchHandler) OnFetched(content []byte, desc ocispec.Descriptor) error {
+	switch desc.MediaType {
+	case ocispec.MediaTypeImageManifest, docker.MediaTypeManifest:
+		var manifest ocispec.Manifest
+		if err := json.Unmarshal(content, &manifest); err != nil {
+			return err
+		}
+		return printJSON(h.out, model.ToMappable(reflect.ValueOf(manifest)))
+	default:
+		return fmt.Errorf("cannot apply template: unsupported media type %s", desc.MediaType)
+	}
+}

cmd/oras/internal/display/metadata/model/mappable.go

@@ -25,18 +25,8 @@ import (
 func ToMappable(v reflect.Value) any {
 	switch v.Kind() {
 	case reflect.Struct:
-		t := v.Type()
-		numField := t.NumField()
 		ret := make(map[string]any)
-		for i := 0; i < numField; i++ {
-			fv := v.Field(i)
-			tag := t.Field(i).Tag.Get("json")
-			if tag == "" {
-				continue
-			}
-			key, _, _ := strings.Cut(tag, ",")
-			ret[key] = ToMappable(fv)
-		}
+		addToMap(ret, v)
 		return ret
 	case reflect.Slice, reflect.Array:
 		ret := make([]any, v.Len())
@@ -53,3 +43,19 @@ func ToMappable(v reflect.Value) any {
 	}
 	return v.Interface()
 }
+
+func addToMap(ret map[string]any, v reflect.Value) {
+	t := v.Type()
+	numField := t.NumField()
+	for i := 0; i < numField; i++ {
+		fv := v.Field(i)
+		ft := t.Field(i)
+		tag := ft.Tag.Get("json")
+		if tag == "" {
+			addToMap(ret, fv)
+		} else {
+			key, _, _ := strings.Cut(tag, ",")
+			ret[key] = ToMappable(fv)
+		}
+	}
+}

cmd/oras/internal/display/metadata/template/manifest_fetch.go

@@ -16,12 +16,15 @@ limitations under the License.
 package template
 
 import (
+	"encoding/json"
+	"fmt"
 	"io"
 	"reflect"
 
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"oras.land/oras/cmd/oras/internal/display/metadata"
 	"oras.land/oras/cmd/oras/internal/display/metadata/model"
+	"oras.land/oras/internal/docker"
 )
 
 // ManifestFetchHandler handles JSON metadata output for manifest fetch events.
@@ -39,6 +42,15 @@ func NewManifestFetchHandler(out io.Writer, template string) metadata.ManifestFe
 }
 
 // OnFetched is called after the manifest fetch is completed.
-func (h *ManifestFetchHandler) OnFetched(manifest ocispec.Manifest) error {
-	return parseAndWrite(h.out, model.ToMappable(reflect.ValueOf(manifest)), h.template)
+func (h *ManifestFetchHandler) OnFetched(content []byte, desc ocispec.Descriptor) error {
+	switch desc.MediaType {
+	case ocispec.MediaTypeImageManifest, docker.MediaTypeManifest:
+		var manifest ocispec.Manifest
+		if err := json.Unmarshal(content, &manifest); err != nil {
+			return err
+		}
+		return parseAndWrite(h.out, model.ToMappable(reflect.ValueOf(manifest)), h.template)
+	default:
+		return fmt.Errorf("cannot apply template: unsupported media type %s", desc.MediaType)
+	}
 }

cmd/oras/internal/display/raw/discard.go

@@ -0,0 +1,33 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package raw
+
+import (
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+type discard struct{}
+
+// OnContentFetched implements ManifestFetchHandler.
+func (discard) OnContentFetched(string, []byte) error { return nil }
+
+// OnDescriptorFetched implements ManifestFetchHandler.
+func (discard) OnDescriptorFetched(desc ocispec.Descriptor) error { return nil }
+
+// NewManifestFetchHandler creates a new handler.
+func NewDiscardHandler() ManifestFetchHandler {
+	return discard{}
+}

cmd/oras/internal/display/raw/interface.go

@@ -0,0 +1,29 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package raw
+
+import (
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+// ManifestFetchHandler handles raw output for manifest fetch events.
+type ManifestFetchHandler interface {
+	// OnFetched is called after the manifest content is fetched.
+	OnContentFetched(outputPath string, content []byte) error
+	// OnDescriptorFetched is called after the manifest descriptor is
+	// fetched.
+	OnDescriptorFetched(desc ocispec.Descriptor) error
+}

cmd/oras/internal/display/raw/manifest_fetch.go

@@ -0,0 +1,76 @@
+/*
+Copyright The ORAS Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package raw
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+// RawManifestFetch handles raw content output.
+type RawManifestFetch struct {
+	pretty bool
+	stdout io.Writer
+}
+
+// OnContentFetched implements ManifestFetchHandler.
+func (h *RawManifestFetch) OnContentFetched(outputPath string, manifest []byte) error {
+	out := h.stdout
+	if outputPath != "-" && outputPath != "" {
+		f, err := os.OpenFile(outputPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0666)
+		if err != nil {
+			return fmt.Errorf("failed to open %q: %w", outputPath, err)
+		}
+		defer f.Close()
+	}
+	return h.output(out, manifest)
+}
+
+// OnDescriptorFetched implements ManifestFetchHandler.
+func (h *RawManifestFetch) OnDescriptorFetched(desc ocispec.Descriptor) error {
+	descBytes, err := json.Marshal(desc)
+	if err != nil {
+		return fmt.Errorf("invalid descriptor: %w", err)
+	}
+	return h.output(h.stdout, descBytes)
+}
+
+// NewManifestFetchHandler creates a new handler.
+func NewManifestFetchHandler(out io.Writer, pretty bool) ManifestFetchHandler {
+	return &RawManifestFetch{
+		pretty: pretty,
+		stdout: out,
+	}
+}
+
+// OnFetched is called after the content is fetched.
+func (h *RawManifestFetch) output(out io.Writer, data []byte) error {
+	if h.pretty {
+		buf := bytes.NewBuffer(nil)
+		if err := json.Indent(buf, data, "", "  "); err != nil {
+			return fmt.Errorf("failed to prettify: %w", err)
+		}
+		buf.WriteByte('\n')
+		data = buf.Bytes()
+	}
+	_, err := out.Write(data)
+	return err
+}