Add initial push-pull implementation

Signed-off-by: Radu M <root@radu.sh>

Gopkg.toml

@@ -101,3 +101,8 @@
   # version imported by k8s.io/client-go @ kubernetes-1.11.2
   name = "github.com/Azure/go-autorest"
   revision = "1ff28809256a84bb6966640ff3d0371af82ccba4"
+
+[[constraint]]
+  name = "github.com/docker/cnab-to-oci"
+  source = "github.com/radu-matei/cnab-to-oci"
+  branch = "sync-bundle"

cmd/duffle/pull.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"path/filepath"
+
+	"github.com/deislabs/duffle/pkg/duffle/home"
+	"github.com/deislabs/duffle/pkg/reference"
+
+	"github.com/deislabs/cnab-go/bundle"
+	"github.com/docker/cnab-to-oci/remotes"
+	"github.com/spf13/cobra"
+)
+
+type pullCmd struct {
+	output             string
+	targetRef          string
+	insecureRegistries []string
+	home               home.Home
+}
+
+func newPullCmd(w io.Writer) *cobra.Command {
+	const usage = `Pulls a bundle from an OCI repository`
+	const pullDesc = `
+Pulls a CNAB bundle from an OCI repository.
+The only argument for this command is the repository where
+the bundle can be found, and by default, this command pulls the
+bundle and stores it in the local bundle store.
+
+If the --output flag is passed, the bundle file will be saved in
+that file, and its reference will not be recorded in the local store.
+
+Insecure registries can be passed through the --insecure-registries flags.
+
+Examples:
+$ duffle pull registry/username/bundle:tag
+$ duffle pull --output path-for-bundle.json registry/username/bundle:tag
+`
+	var pull pullCmd
+	cmd := &cobra.Command{
+		Use:   "pull [TARGET REPOSITORY] [options]",
+		Short: usage,
+		Long:  pullDesc,
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			pull.targetRef = args[0]
+			pull.home = home.Home(homePath())
+			return pull.run()
+		},
+	}
+
+	cmd.Flags().StringVarP(&pull.output, "output", "o", "", "Output file")
+	cmd.Flags().StringSliceVar(&pull.insecureRegistries, "insecure-registries", nil, "Use plain HTTP for those registries")
+	return cmd
+}
+
+func (p *pullCmd) run() error {
+	ref, err := reference.ParseNormalizedNamed(p.targetRef)
+	if err != nil {
+		return err
+	}
+	b, err := remotes.Pull(context.Background(), ref, createResolver(p.insecureRegistries))
+	if err != nil {
+		return err
+	}
+
+	return p.writeBundle(b)
+}
+
+func (p *pullCmd) writeBundle(bf *bundle.Bundle) error {
+	data, digest, err := marshalBundle(bf)
+	if err != nil {
+		return fmt.Errorf("cannot marshal bundle: %v", err)
+	}
+
+	if p.output != "" {
+		if err := ioutil.WriteFile(p.output, data, 0644); err != nil {
+			return fmt.Errorf("cannot write bundle to %s: %v", p.output, err)
+		}
+		return nil
+	}
+
+	if err := ioutil.WriteFile(filepath.Join(p.home.Bundles(), digest), data, 0644); err != nil {
+		return fmt.Errorf("cannot store bundle : %v", err)
+
+	}
+
+	return recordBundleReference(p.home, bf.Name, bf.Version, digest)
+
+}

cmd/duffle/push.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/deislabs/duffle/pkg/duffle/home"
+	"github.com/deislabs/duffle/pkg/reference"
+
+	containerdRemotes "github.com/containerd/containerd/remotes"
+	"github.com/docker/cli/cli/config"
+	"github.com/docker/cnab-to-oci/remotes"
+	"github.com/spf13/cobra"
+)
+
+type pushCmd struct {
+	inputBundle        string
+	home               home.Home
+	bundleIsFile       bool
+	targetRef          string
+	insecureRegistries []string
+	allowFallbacks     bool
+}
+
+func newPushCmd(out io.Writer) *cobra.Command {
+	const usage = `Pushes a CNAB bundle to an OCI repository.`
+	const pushDesc = `
+Pushes a CNAB bundle to an OCI registry by pushing all container
+images referenced in the bundle to the target repository (all images are
+pushed to the same repository, and are referenceable through their digest).
+
+The first argument is the bundle to push (or the path to the bundle file, if the
+--bundle-is-file flag is passed), and the second argument is the target repository
+where the bundle and all referenced images will be pushed.
+
+Insecure registries can be passed through the --insecure-registries flags,
+and --allow-fallbacks enables automatic compatibility fallbacks for registries
+without support for custom media type, or OCI manifests.
+
+Examples:
+$ duffle push bundle-reference registry/usernamne/bundle:tag
+$ duffle push path-to-bundle.json --bundle-is-file registtry/username/bundle:tag
+`
+	var push pushCmd
+
+	cmd := &cobra.Command{
+		Use:   "push [BUNDLE] [TARGET REPOSITORY] [options]",
+		Short: usage,
+		Long:  pushDesc,
+		Args:  cobra.ExactArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			push.home = home.Home(homePath())
+			push.inputBundle = args[0]
+			push.targetRef = args[1]
+			return push.run()
+		},
+	}
+
+	cmd.Flags().BoolVarP(&push.bundleIsFile, "bundle-is-file", "f", false, "Indicates that the bundle source is a file path")
+	cmd.Flags().StringSliceVar(&push.insecureRegistries, "insecure-registries", nil, "Use plain HTTP for those registries")
+	cmd.Flags().BoolVar(&push.allowFallbacks, "allow-fallbacks", true, "Enable automatic compatibility fallbacks for registries without support for custom media type, or OCI manifests")
+
+	return cmd
+}
+
+func (p *pushCmd) run() error {
+
+	bundleFile, err := resolveBundleFilePath(p.inputBundle, p.home.String(), p.bundleIsFile)
+	if err != nil {
+		return err
+	}
+
+	b, err := loadBundle(bundleFile)
+	if err != nil {
+		return err
+	}
+
+	resolver := createResolver(p.insecureRegistries)
+	ref, err := reference.ParseNormalizedNamed(p.targetRef)
+	if err != nil {
+		return err
+	}
+
+	err = remotes.FixupBundle(context.Background(), b, ref, resolver, remotes.WithEventCallback(displayEvent))
+	if err != nil {
+		return err
+	}
+	d, err := remotes.Push(context.Background(), b, ref, resolver, p.allowFallbacks)
+	if err != nil {
+		return err
+	}
+	fmt.Printf("Pushed successfully, with digest %q\n", d.Digest)
+	return nil
+}
+
+func createResolver(insecureRegistries []string) containerdRemotes.Resolver {
+	return remotes.CreateResolver(config.LoadDefaultConfigFile(os.Stderr), insecureRegistries...)
+}
+
+func displayEvent(ev remotes.FixupEvent) {
+	switch ev.EventType {
+	case remotes.FixupEventTypeCopyImageStart:
+		fmt.Fprintf(os.Stderr, "Starting to copy image %s...\n", ev.SourceImage)
+	case remotes.FixupEventTypeCopyImageEnd:
+		if ev.Error != nil {
+			fmt.Fprintf(os.Stderr, "Failed to copy image %s: %s\n", ev.SourceImage, ev.Error)
+		} else {
+			fmt.Fprintf(os.Stderr, "Completed image %s copy\n", ev.SourceImage)
+		}
+	}
+}

cmd/duffle/root.go

@@ -59,6 +59,8 @@ func newRootCmd(outputRedirect io.Writer) *cobra.Command {
 		newExportCmd(outLog),
 		newImportCmd(outLog),
 		newCreateCmd(outLog),
+		newPullCmd(outLog),
+		newPushCmd(outLog),
 	)
 
 	return cmd