Add Command Line Tools (#3)

* Add pull command

* Add push cmd

cmd/oras/main.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+func main() {
+	cmd := &cobra.Command{
+		Use:          "oras [OPTIONS] COMMAND",
+		SilenceUsage: true,
+	}
+	cmd.AddCommand(pullCmd(), pushCmd())
+	if err := cmd.Execute(); err != nil {
+		os.Exit(1)
+	}
+}

cmd/oras/pull.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"context"
+	"io/ioutil"
+	"path"
+
+	"github.com/shizhMSFT/oras/pkg/oras"
+
+	"github.com/spf13/cobra"
+)
+
+type pullOptions struct {
+	targetRef string
+	output    string
+	username  string
+	password  string
+}
+
+func pullCmd() *cobra.Command {
+	var opts pullOptions
+	cmd := &cobra.Command{
+		Use:   "pull [OPTIONS] NAME[:TAG|@DIGEST]",
+		Short: "Pull files from remote registry",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			opts.targetRef = args[0]
+			return runPull(opts)
+		},
+	}
+
+	cmd.Flags().StringVarP(&opts.output, "output", "o", "", "output directory")
+	cmd.Flags().StringVarP(&opts.username, "username", "u", "", "registry username")
+	cmd.Flags().StringVarP(&opts.password, "password", "p", "", "registry password")
+	return cmd
+}
+
+func runPull(opts pullOptions) error {
+	resolver := newResolver(opts.username, opts.password)
+	contents, err := oras.Pull(context.Background(), resolver, opts.targetRef)
+	if err != nil {
+		return err
+	}
+
+	for name, content := range contents {
+		if opts.output != "" {
+			name = path.Join(opts.output, name)
+		}
+		if err := ioutil.WriteFile(name, content, 0644); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

cmd/oras/push.go

@@ -0,0 +1,50 @@
+package main
+
+import (
+	"context"
+	"io/ioutil"
+
+	"github.com/shizhMSFT/oras/pkg/oras"
+
+	"github.com/spf13/cobra"
+)
+
+type pushOptions struct {
+	targetRef string
+	filenames []string
+	username  string
+	password  string
+}
+
+func pushCmd() *cobra.Command {
+	var opts pushOptions
+	cmd := &cobra.Command{
+		Use:   "push [OPTIONS] NAME[:TAG|@DIGEST] FILE [FILE...]",
+		Short: "Push files to remote registry",
+		Args:  cobra.MinimumNArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			opts.targetRef = args[0]
+			opts.filenames = args[1:]
+			return runPush(opts)
+		},
+	}
+
+	cmd.Flags().StringVarP(&opts.username, "username", "u", "", "registry username")
+	cmd.Flags().StringVarP(&opts.password, "password", "p", "", "registry password")
+	return cmd
+}
+
+func runPush(opts pushOptions) error {
+	resolver := newResolver(opts.username, opts.password)
+
+	contents := make(map[string][]byte)
+	for _, filename := range opts.filenames {
+		content, err := ioutil.ReadFile(filename)
+		if err != nil {
+			return err
+		}
+		contents[filename] = content
+	}
+
+	return oras.Push(context.Background(), resolver, opts.targetRef, contents)
+}

cmd/oras/resolver.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"os"
+
+	"github.com/containerd/containerd/remotes"
+	"github.com/containerd/containerd/remotes/docker"
+	"github.com/docker/cli/cli/config"
+	"github.com/docker/docker/registry"
+)
+
+func newResolver(username, password string) remotes.Resolver {
+	cfg := config.LoadDefaultConfigFile(os.Stderr)
+	credential := func(hostName string) (string, string, error) {
+		if hostName == registry.DefaultV2Registry.Host {
+			hostName = registry.IndexServer
+		}
+		auth, err := cfg.GetAuthConfig(hostName)
+		if err != nil {
+			return "", "", err
+		}
+		if auth.IdentityToken != "" {
+			return "", auth.IdentityToken, nil
+		}
+		return auth.Username, auth.Password, nil
+	}
+	if username != "" {
+		credential = func(hostName string) (string, string, error) {
+			return username, password, nil
+		}
+	}
+	return docker.NewResolver(docker.ResolverOptions{
+		Credentials: credential,
+	})
+}