build-using-dockerfile: add --annotation

Add an --annotation flag to "buildah build-using-dockerfile".

Refactor the logic for --label handling to use SetLabel() to set them in
the image configuration in Executor.Commit(), instead of passing them as
a field in CommitOptions for Builder.Commit() and expecting it to do so.

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

Closes: #716
Approved by: rhatdan

cmd/buildah/bud.go

@@ -185,6 +185,7 @@ func budCmd(c *cli.Context) error {
 		IIDFile:               c.String("iidfile"),
 		Squash:                c.Bool("squash"),
 		Labels:                c.StringSlice("label"),
+		Annotations:           c.StringSlice("annotation"),
 	}
 
 	if !c.Bool("quiet") {

commit.go

@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
-	"strings"
 	"time"
 
 	cp "github.com/containers/image/copy"
@@ -53,8 +52,6 @@ type CommitOptions struct {
 	// Squash tells the builder to produce an image with a single layer
 	// instead of with possibly more than one layer.
 	Squash bool
-	// Labels metadata for an image
-	Labels []string
 }
 
 // PushOptions can be used to alter how an image is copied somewhere.
@@ -89,15 +86,6 @@ type PushOptions struct {
 func (b *Builder) Commit(ctx context.Context, dest types.ImageReference, options CommitOptions) (string, error) {
 	var imgID string
 
-	for _, labelSpec := range options.Labels {
-		label := strings.SplitN(labelSpec, "=", 2)
-		if len(label) > 1 {
-			b.SetLabel(label[0], label[1])
-		} else {
-			b.SetLabel(label[0], "")
-		}
-	}
-
 	systemContext := getSystemContext(options.SystemContext, options.SignaturePolicyPath)
 	policy, err := signature.DefaultPolicy(systemContext)
 	if err != nil {

contrib/completions/bash/buildah

@@ -366,6 +366,7 @@ return 1
 
      local options_with_args="
      --add-host
+     --annotation
      --authfile
      --build-arg
      --cert-dir

docs/buildah-bud.md

@@ -26,6 +26,12 @@ Add a custom host-to-IP mapping (host:ip)
 
 Add a line to /etc/hosts. The format is hostname:ip. The **--add-host** option can be set multiple times.
 
+**--annotation** *annotation*
+
+Add an image *annotation* (e.g. annotation=*value*) to the image metadata. Can be used multiple times.
+
+Note: this information is not present in Docker image formats, so it is discarded when writing images in Docker formats.
+
 **--authfile** *path*
 
 Path of the authentication file. Default is ${XDG\_RUNTIME\_DIR}/containers/auth.json, which is set using `podman login`.

imagebuildah/build.go

@@ -118,6 +118,8 @@ type BuildOptions struct {
 	Squash bool
 	// Labels metadata for an image
 	Labels []string
+	// Annotation metadata for an image
+	Annotations []string
 }
 
 // Executor is a buildah-based implementation of the imagebuilder.Executor
@@ -157,6 +159,7 @@ type Executor struct {
 	iidfile                        string
 	squash                         bool
 	labels                         []string
+	annotations                    []string
 }
 
 // withName creates a new child executor that will be used whenever a COPY statement uses --from=NAME.
@@ -490,7 +493,8 @@ func NewExecutor(store storage.Store, options BuildOptions) (*Executor, error) {
 		defaultMountsFilePath: options.DefaultMountsFilePath,
 		iidfile:               options.IIDFile,
 		squash:                options.Squash,
-		labels:                options.Labels,
+		labels:                append([]string{}, options.Labels...),
+		annotations:           append([]string{}, options.Annotations...),
 	}
 	if exec.err == nil {
 		exec.err = os.Stderr
@@ -682,6 +686,22 @@ func (b *Executor) Commit(ctx context.Context, ib *imagebuilder.Builder) (err er
 	for k, v := range config.Labels {
 		b.builder.SetLabel(k, v)
 	}
+	for _, labelSpec := range b.labels {
+		label := strings.SplitN(labelSpec, "=", 2)
+		if len(label) > 1 {
+			b.builder.SetLabel(label[0], label[1])
+		} else {
+			b.builder.SetLabel(label[0], "")
+		}
+	}
+	for _, annotationSpec := range b.annotations {
+		annotation := strings.SplitN(annotationSpec, "=", 2)
+		if len(annotation) > 1 {
+			b.builder.SetAnnotation(annotation[0], annotation[1])
+		} else {
+			b.builder.SetAnnotation(annotation[0], "")
+		}
+	}
 	if imageRef != nil {
 		logName := transports.ImageName(imageRef)
 		logrus.Debugf("COMMIT %q", logName)
@@ -702,7 +722,6 @@ func (b *Executor) Commit(ctx context.Context, ib *imagebuilder.Builder) (err er
 		PreferredManifestType: b.outputFormat,
 		IIDFile:               b.iidfile,
 		Squash:                b.squash,
-		Labels:                b.labels,
 	}
 	imgID, err := b.builder.Commit(ctx, imageRef, options)
 	if err != nil {

pkg/cli/common.go

@@ -11,6 +11,10 @@ import (
 
 var (
 	BudFlags = []cli.Flag{
+		cli.StringSliceFlag{
+			Name:  "annotation",
+			Usage: "Set metadata for an image (default [])",
+		},
 		cli.StringFlag{
 			Name:  "authfile",
 			Usage: "path of the authentication file. Default is ${XDG_RUNTIME_DIR}/containers/auth.json",

tests/bud.bats

@@ -37,6 +37,16 @@ load helpers
   buildah rmi ${target}
 }
 
+@test "bud-from-scratch-annotation" {
+  target=scratch-image
+  buildah bud --annotation "test=annotation" --signature-policy ${TESTSDIR}/policy.json -t ${target} ${TESTSDIR}/bud/from-scratch
+  run buildah --debug=false inspect --format '{{printf "%q" .ImageAnnotations}}' ${target}
+  echo "$output"
+  [ "$status" -eq 0 ]
+  [ "$output" = 'map["test":"annotation"]' ]
+  buildah rmi ${target}
+}
+
 @test "bud-from-multiple-files-one-from" {
   target=scratch-image
   buildah bud --signature-policy ${TESTSDIR}/policy.json -t ${target} -f ${TESTSDIR}/bud/from-multiple-files/Dockerfile1.scratch -f ${TESTSDIR}/bud/from-multiple-files/Dockerfile2.nofrom