image: Refactor to use cas/ref engines instead of walkers

.tool/lint

@@ -14,6 +14,11 @@ for d in $(find . -type d -not -iwholename '*.git*' -a -not -iname '.tool' -a -n
 		--exclude='error return value not checked.*(Close|Log|Print).*\(errcheck\)$' \
 		--exclude='.*_test\.go:.*error return value not checked.*\(errcheck\)$' \
 		--exclude='duplicate of.*_test.go.*\(dupl\)$' \
+		--exclude='^cmd/oci-image-tool/cas_get.go:.* duplicate of .* \(dupl\)$' \
+		--exclude='^cmd/oci-image-tool/cas_put.go:.* duplicate of .* \(dupl\)$' \
+		--exclude='^cmd/oci-image-tool/refs_get.go:.* duplicate of .* \(dupl\)$' \
+		--exclude='^cmd/oci-image-tool/refs_list.go:.* duplicate of .* \(dupl\)$' \
+		--exclude='^cmd/oci-image-tool/refs_put.go:.* duplicate of .* \(dupl\)$' \
 		--exclude='schema/fs.go' \
 		--disable=aligncheck \
 		--disable=gotype \

cmd/oci-image-tool/autodetect.go

@@ -27,7 +27,6 @@ import (
 
 // supported autodetection types
 const (
-	typeImageLayout  = "imageLayout"
 	typeImage        = "image"
 	typeManifest     = "manifest"
 	typeManifestList = "manifestList"
@@ -43,7 +42,7 @@ func autodetect(path string) (string, error) {
 	}
 
 	if fi.IsDir() {
-		return typeImageLayout, nil
+		return typeImage, nil
 	}
 
 	f, err := os.Open(path)

cmd/oci-image-tool/cas.go

@@ -0,0 +1,34 @@
+// Copyright 2016 The Linux Foundation
+//
+// 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 main
+
+import (
+	"io"
+	"log"
+
+	"github.com/spf13/cobra"
+)
+
+func newCASCmd(stdout io.Writer, stderr *log.Logger) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "cas",
+		Short: "Content-addressable storage manipulation",
+	}
+
+	cmd.AddCommand(newCASGetCmd(stdout, stderr))
+	cmd.AddCommand(newCASPutCmd(stdout, stderr))
+
+	return cmd
+}

cmd/oci-image-tool/cas_get.go

@@ -0,0 +1,100 @@
+// Copyright 2016 The Linux Foundation
+//
+// 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 main
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+
+	"github.com/opencontainers/image-spec/image/cas/layout"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+type casGetCmd struct {
+	stdout io.Writer
+	stderr *log.Logger
+	path   string
+	digest string
+}
+
+func newCASGetCmd(stdout io.Writer, stderr *log.Logger) *cobra.Command {
+	state := &casGetCmd{
+		stdout: stdout,
+		stderr: stderr,
+	}
+
+	return &cobra.Command{
+		Use:   "get PATH DIGEST",
+		Short: "Retrieve a blob from the store",
+		Long:  "Retrieve a blob from the store and write it to stdout.",
+		Run:   state.Run,
+	}
+}
+
+func (state *casGetCmd) Run(cmd *cobra.Command, args []string) {
+	if len(args) != 2 {
+		state.stderr.Print("both PATH and DIGEST must be provided")
+		if err := cmd.Usage(); err != nil {
+			state.stderr.Println(err)
+		}
+		os.Exit(1)
+	}
+
+	state.path = args[0]
+	state.digest = args[1]
+
+	err := state.run()
+	if err != nil {
+		state.stderr.Println(err)
+		os.Exit(1)
+	}
+
+	os.Exit(0)
+}
+
+func (state *casGetCmd) run() (err error) {
+	ctx := context.Background()
+
+	engine, err := layout.NewEngine(ctx, state.path)
+	if err != nil {
+		return err
+	}
+	defer engine.Close()
+
+	reader, err := engine.Get(ctx, state.digest)
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+
+	bytes, err := ioutil.ReadAll(reader)
+	if err != nil {
+		return err
+	}
+
+	n, err := state.stdout.Write(bytes)
+	if err != nil {
+		return err
+	}
+	if n < len(bytes) {
+		return fmt.Errorf("wrote %d of %d bytes", n, len(bytes))
+	}
+
+	return nil
+}

cmd/oci-image-tool/cas_put.go

@@ -0,0 +1,90 @@
+// Copyright 2016 The Linux Foundation
+//
+// 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 main
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"os"
+
+	"github.com/opencontainers/image-spec/image/cas/layout"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+type casPutCmd struct {
+	stdout io.Writer
+	stderr *log.Logger
+	path   string
+}
+
+func newCASPutCmd(stdout io.Writer, stderr *log.Logger) *cobra.Command {
+	state := &casPutCmd{
+		stdout: stdout,
+		stderr: stderr,
+	}
+
+	return &cobra.Command{
+		Use:   "put PATH",
+		Short: "Write a blob to the store",
+		Long:  "Read a blob from stdin, write it to the store, and print the digest to stdout.",
+		Run:   state.Run,
+	}
+}
+
+func (state *casPutCmd) Run(cmd *cobra.Command, args []string) {
+	if len(args) != 1 {
+		if err := cmd.Usage(); err != nil {
+			state.stderr.Println(err)
+		}
+		os.Exit(1)
+	}
+
+	state.path = args[0]
+
+	err := state.run()
+	if err != nil {
+		state.stderr.Println(err)
+		os.Exit(1)
+	}
+
+	os.Exit(0)
+}
+
+func (state *casPutCmd) run() (err error) {
+	ctx := context.Background()
+
+	engine, err := layout.NewEngine(ctx, state.path)
+	if err != nil {
+		return err
+	}
+	defer engine.Close()
+
+	digest, err := engine.Put(ctx, os.Stdin)
+	if err != nil {
+		return err
+	}
+
+	n, err := fmt.Fprintln(state.stdout, digest)
+	if err != nil {
+		return err
+	}
+	if n < len(digest) {
+		return fmt.Errorf("wrote %d of %d bytes", n, len(digest))
+	}
+
+	return nil
+}

cmd/oci-image-tool/create_runtime_bundle.go

@@ -22,11 +22,11 @@ import (
 
 	"github.com/opencontainers/image-spec/image"
 	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
 )
 
 // supported bundle types
 var bundleTypes = []string{
-	typeImageLayout,
 	typeImage,
 }
 
@@ -82,6 +82,8 @@ func (v *bundleCmd) Run(cmd *cobra.Command, args []string) {
 		os.Exit(1)
 	}
 
+	ctx := context.Background()
+
 	if _, err := os.Stat(args[1]); os.IsNotExist(err) {
 		v.stderr.Printf("destination path %s does not exist", args[1])
 		os.Exit(1)
@@ -98,11 +100,8 @@ func (v *bundleCmd) Run(cmd *cobra.Command, args []string) {
 
 	var err error
 	switch v.typ {
-	case typeImageLayout:
-		err = image.CreateRuntimeBundleLayout(args[0], args[1], v.ref, v.root)
-
 	case typeImage:
-		err = image.CreateRuntimeBundle(args[0], args[1], v.ref, v.root)
+		err = image.CreateRuntimeBundle(ctx, args[0], args[1], v.ref, v.root)
 	}
 
 	if err != nil {

cmd/oci-image-tool/init.go

@@ -0,0 +1,33 @@
+// Copyright 2016 The Linux Foundation
+//
+// 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 main
+
+import (
+	"io"
+	"log"
+
+	"github.com/spf13/cobra"
+)
+
+func newInitCmd(stdout io.Writer, stderr *log.Logger) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "init",
+		Short: "Initialize an OCI image",
+	}
+
+	cmd.AddCommand(newInitImageLayoutCmd(stdout, stderr))
+
+	return cmd
+}

cmd/oci-image-tool/init_image_layout.go

@@ -0,0 +1,62 @@
+// Copyright 2016 The Linux Foundation
+//
+// 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 main
+
+import (
+	"io"
+	"log"
+	"os"
+
+	"github.com/opencontainers/image-spec/image/layout"
+	"github.com/spf13/cobra"
+	"golang.org/x/net/context"
+)
+
+type initImageLayout struct {
+	stderr *log.Logger
+}
+
+func newInitImageLayoutCmd(stdout io.Writer, stderr *log.Logger) *cobra.Command {
+	state := &initImageLayout{
+		stderr: stderr,
+	}
+
+	return &cobra.Command{
+		Use:   "image-layout PATH",
+		Short: "Initialize an OCI image-layout repository",
+		Run:   state.Run,
+	}
+}
+
+func (state *initImageLayout) Run(cmd *cobra.Command, args []string) {
+	if len(args) != 1 {
+		if err := cmd.Usage(); err != nil {
+			state.stderr.Println(err)
+		}
+		os.Exit(1)
+	}
+
+	path := args[0]
+
+	ctx := context.Background()
+
+	err := layout.CreateTarFile(ctx, path)
+	if err != nil {
+		state.stderr.Println(err)
+		os.Exit(1)
+	}
+
+	os.Exit(0)
+}