Increase the generate function

Signed-off-by: zhouhao <zhouhao@cn.fujitsu.com>

.gitignore

@@ -1,3 +1,4 @@
 /oci-create-runtime-bundle
 /oci-unpack
 /oci-image-validate
+/oci-generate

Makefile

@@ -7,7 +7,8 @@ EPOCH_TEST_COMMIT ?= v0.2.0
 TOOLS := \
 	oci-create-runtime-bundle \
 	oci-image-validate \
-	oci-unpack
+	oci-unpack \
+	oci-generate
 
 default: help
 

cmd/oci-generate/main.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 (
+	"log"
+	"os"
+
+	specs "github.com/opencontainers/image-spec/specs-go"
+	"github.com/opencontainers/image-tools/image"
+	"github.com/spf13/cobra"
+)
+
+// gitCommit will be the hash that the binary was built from
+// and will be populated by the Makefile
+var gitCommit = ""
+
+type generateCmd struct {
+	stdout  *log.Logger
+	stderr  *log.Logger
+	version bool
+}
+
+func main() {
+	stdout := log.New(os.Stdout, "", 0)
+	stderr := log.New(os.Stderr, "", 0)
+
+	cmd := newGenerateCmd(stdout, stderr)
+	if err := cmd.Execute(); err != nil {
+		stderr.Println(err)
+		os.Exit(1)
+	}
+}
+
+func newGenerateCmd(stdout, stderr *log.Logger) *cobra.Command {
+	v := &generateCmd{
+		stdout: stdout,
+		stderr: stderr,
+	}
+
+	cmd := &cobra.Command{
+		Use:   "generate [dest]",
+		Short: "Generate an OCI imageLayout",
+		Long:  `Generate the OCI imageLayout to the destination directory [dest].`,
+		Run:   v.Run,
+	}
+
+	cmd.Flags().BoolVarP(
+		&v.version, "version", "v", false,
+		`Print version information and exit`,
+	)
+
+	origHelp := cmd.HelpFunc()
+
+	cmd.SetHelpFunc(func(c *cobra.Command, args []string) {
+		origHelp(c, args)
+		stdout.Println("\nMore information:")
+		stdout.Printf("\treferences\t%s\n", image.SpecURL)
+		stdout.Printf("\tbug report\t%s\n", image.IssuesURL)
+	})
+
+	return cmd
+}
+
+func (v *generateCmd) Run(cmd *cobra.Command, args []string) {
+	if v.version {
+		v.stdout.Printf("commit: %s", gitCommit)
+		v.stdout.Printf("spec: %s", specs.Version)
+		os.Exit(0)
+	}
+
+	if len(args) != 1 {
+		v.stderr.Print("dest must be provided")
+		if err := cmd.Usage(); err != nil {
+			v.stderr.Println(err)
+		}
+		os.Exit(1)
+	}
+
+	err := image.Generate(args[0])
+
+	if err != nil {
+		v.stderr.Printf("generating failed: %v", err)
+		os.Exit(1)
+	}
+
+	os.Exit(0)
+}