Increase the generate function

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

.gitignore

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

Makefile

@@ -6,8 +6,10 @@ COMMIT=$(shell git rev-parse HEAD 2> /dev/null || true)
 EPOCH_TEST_COMMIT ?= v0.2.0
 TOOLS := \
 	oci-create-runtime-bundle \
+	oci-generate \
 	oci-image-validate \
 	oci-unpack
+
 MAN := $(TOOLS:%=%.1)
 
 default: help

cmd/oci-generate/main.go

@@ -0,0 +1,124 @@
+// 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"
+	"log"
+	"os"
+	"strings"
+
+	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 = ""
+
+var generateTypes = []string{
+	"imageLayout",
+	"image",
+}
+
+type generateCmd struct {
+	stdout  *log.Logger
+	stderr  *log.Logger
+	typ     string //the type to generate, can be empty string
+	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 image or an imageLayout",
+		Long:  `Generate the OCI iamge or imageLayout to the destination directory [dest].`,
+		Run:   v.Run,
+	}
+
+	cmd.Flags().StringVar(
+		&v.typ, "type", "imageLayout",
+		fmt.Sprintf(
+			`Type of the file to generate, one of "%s".`,
+			strings.Join(generateTypes, ","),
+		),
+	)
+
+	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)
+	}
+
+	var err error
+	switch v.typ {
+	case "imageLayout":
+		err = image.GenerateLayout(args[0])
+	case "image":
+		err = image.Generate(args[0])
+	default:
+		err = fmt.Errorf("unsupport type %q", v.typ)
+	}
+
+	if err != nil {
+		v.stderr.Printf("generating failed: %v", err)
+		os.Exit(1)
+	}
+
+	os.Exit(0)
+}

cmd/oci-generate/oci-generate.1.md

@@ -0,0 +1,40 @@
+% OCI(1) OCI-UNPACK User Manuals
+% OCI Community
+% JULY 2016
+# NAME
+oci-generate \- Generate an OCI image or an OCI imageLayout
+
+# SYNOPSIS
+**oci-unpack** [dest] [flags]
+**oci-unpack** [--help|--version]
+
+# DESCRIPTION
+`oci-generate` generate an application/vnd.oci.image.manifest.v1+json or application/vnd.oci.image.manifest.list+json to `dest`.
+
+# OPTIONS
+**--help**
+  Print usage statement
+
+**--type**
+  Type of the file to generate.One of "imageLayout,image".(detault "imageLayout")
+
+**--version**
+  Print version information and exit.
+
+# EXAMPLES
+```
+$ oci-generate example
+$ tree example
+example
+├── blobs
+│   └── sha256
+│       ├── 5d82e6cbf19cd18f40301df14ffbd62ba1acae8a097e75011ec603ff38a7450a
+│       ├── 89b46f9224fbcedd165dd6b317329b69182471c6706993bedc2c2d2fd2d76fba
+│       └── a3ed95caeb02ffe68cdd9fd84406680ae93d633cb16422d00e8a7c22955b46d4
+├── oci-layout
+└── refs
+    └── latest
+[...]
+```
+# HISTORY
+Sept 2016, Originally compiled by Antonio Murdaca (runcom at redhat dot com)