imagebuildah: add AdditionalTags

Add an AdditionalTags field to the imagebuildah options structure, to
provide for additional tags which we'll want to apply to the image that
we're writing.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

Closes: #88
Approved by: rhatdan

cmd/buildah/bud.go

@@ -47,7 +47,7 @@ var (
 			Name:  "runtime-flag",
 			Usage: "add global flags for the container runtime",
 		},
-		cli.StringFlag{
+		cli.StringSliceFlag{
 			Name:  "tag, t",
 			Usage: "`tag` to apply to the built image",
 		},
@@ -70,8 +70,13 @@ var (
 
 func budCmd(c *cli.Context) error {
 	output := ""
-	if c.IsSet("tag") {
-		output = c.String("tag")
+	tags := []string{}
+	if c.IsSet("tag") || c.IsSet("t") {
+		tags = c.StringSlice("tag")
+		if len(tags) > 0 {
+			output = tags[0]
+			tags = tags[1:]
+		}
 	}
 	registry := DefaultRegistry
 	if c.IsSet("registry") {
@@ -194,6 +199,7 @@ func budCmd(c *cli.Context) error {
 		SignaturePolicyPath: signaturePolicy,
 		Args:                args,
 		Output:              output,
+		AdditionalTags:      tags,
 		Runtime:             runtime,
 		RuntimeArgs:         runtimeFlags,
 	}

commit.go

@@ -1,8 +1,12 @@
 package buildah
 
 import (
+	"fmt"
+
 	"github.com/containers/image/copy"
+	"github.com/containers/image/docker/reference"
 	"github.com/containers/image/signature"
+	"github.com/containers/image/storage"
 	"github.com/containers/image/types"
 	"github.com/containers/storage/pkg/archive"
 )
@@ -19,10 +23,32 @@ type CommitOptions struct {
 	// specified, indicating that the shared, system-wide default policy
 	// should be used.
 	SignaturePolicyPath string
+	// AdditionalTags is a list of additional names to add to the image, if
+	// the transport to which we're writing the image gives us a way to add
+	// them.
+	AdditionalTags []string
+}
+
+func expandTags(tags []string) ([]string, error) {
+	expanded := []string{}
+	for _, tag := range tags {
+		name, err := reference.ParseNormalizedNamed(tag)
+		if err != nil {
+			return nil, fmt.Errorf("error parsing tag %q: %v", tag, err)
+		}
+		name = reference.TagNameOnly(name)
+		tag = ""
+		if tagged, ok := name.(reference.NamedTagged); ok {
+			tag = ":" + tagged.Tag()
+		}
+		expanded = append(expanded, name.Name()+tag)
+	}
+	return expanded, nil
 }
 
 // Commit writes the contents of the container, along with its updated
-// configuration, to a new image in the specified location.
+// configuration, to a new image in the specified location, and if we know how,
+// add any additional tags that were specified.
 func (b *Builder) Commit(dest types.ImageReference, options CommitOptions) error {
 	policy, err := signature.DefaultPolicy(getSystemContext(options.SignaturePolicyPath))
 	if err != nil {
@@ -37,5 +63,20 @@ func (b *Builder) Commit(dest types.ImageReference, options CommitOptions) error
 		return err
 	}
 	err = copy.Image(policyContext, dest, src, getCopyOptions())
+	switch dest.Transport().Name() {
+	case storage.Transport.Name():
+		tags, err := expandTags(options.AdditionalTags)
+		if err != nil {
+			return err
+		}
+		img, err := storage.Transport.GetStoreImage(b.store, dest)
+		if err != nil {
+			return err
+		}
+		err = b.store.SetNames(img.ID, append(img.Names, tags...))
+		if err != nil {
+			return fmt.Errorf("error setting image names to %v: %v", append(img.Names, tags...), err)
+		}
+	}
 	return err
 }

imagebuildah/build.go

@@ -70,6 +70,9 @@ type BuildOptions struct {
 	Args map[string]string
 	// Name of the image to write to.
 	Output string
+	// Additional tags to add to the image that we write, if we know of a
+	// way to add them.
+	AdditionalTags []string
 	// Log is a callback that will print a progress message.  If no value
 	// is supplied, the message will be sent to Err (or os.Stderr, if Err
 	// is nil) by default.
@@ -101,6 +104,7 @@ type Executor struct {
 	transientMounts                []Mount
 	compression                    archive.Compression
 	output                         string
+	additionalTags                 []string
 	log                            func(format string, args ...interface{})
 	out                            io.Writer
 	err                            io.Writer
@@ -376,6 +380,7 @@ func NewExecutor(store storage.Store, options BuildOptions) (*Executor, error) {
 		transientMounts:     options.TransientMounts,
 		compression:         options.Compression,
 		output:              options.Output,
+		additionalTags:      options.AdditionalTags,
 		signaturePolicyPath: options.SignaturePolicyPath,
 		systemContext:       makeSystemContext(options.SignaturePolicyPath),
 		volumeCache:         make(map[string]string),
@@ -520,6 +525,7 @@ func (b *Executor) Commit(ib *imagebuilder.Builder) (err error) {
 	options := buildah.CommitOptions{
 		Compression:         b.compression,
 		SignaturePolicyPath: b.signaturePolicyPath,
+		AdditionalTags:      b.additionalTags,
 	}
 	return b.builder.Commit(imageRef, options)
 }

tests/bud.bats

@@ -168,3 +168,20 @@ load helpers
   run buildah --debug=false images -q
   [ "$output" = "" ]
 }
+
+@test "bud-additional-tags" {
+  target=scratch-image
+  target2=another-scratch-image
+  target3=so-many-scratch-images
+  buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -t ${target2} -t ${target3} ${TESTSDIR}/bud/from-scratch
+  run buildah --debug=false images
+  cid=$(buildah from ${target})
+  buildah rm ${cid}
+  cid=$(buildah from library/${target2})
+  buildah rm ${cid}
+  cid=$(buildah from ${target3}:latest)
+  buildah rm ${cid}
+  buildah rmi $(buildah --debug=false images -q)
+  run buildah --debug=false images -q
+  [ "$output" = "" ]
+}