Merge pull request #1075 from greut/label-flag

executor: add --label flag

README.md

@@ -68,6 +68,7 @@ _If you are interested in contributing to kaniko, see [DEVELOPMENT.md](DEVELOPME
     - [--tarPath](#--tarpath)
     - [--verbosity](#--verbosity)
     - [--whitelist-var-run](#--whitelist-var-run)
+    - [--label](#--label)
   - [Debug Image](#debug-image)
 - [Security](#security)
 - [Comparison with Other Tools](#comparison-with-other-tools)
@@ -521,6 +522,10 @@ Set this flag as `--verbosity=<panic|fatal|error|warn|info|debug>` to set the lo
 
 Ignore /var/run when taking image snapshot. Set it to false to preserve /var/run/* in destination image. (Default true).
 
+#### --label
+
+Set this flag as `--label key=value` to set some metadata to the final image. This is equivalent as using the `LABEL` within the Dockerfile.
+
 ### Debug Image
 
 The kaniko executor image is based on scratch and doesn't contain a shell.

cmd/executor/cmd/root.go

@@ -158,6 +158,7 @@ func addKanikoOptionsFlags() {
 	RootCmd.PersistentFlags().VarP(&opts.RegistriesCertificates, "registry-certificate", "", "Use the provided certificate for TLS communication with the given registry. Expected format is 'my.registry.url=/path/to/the/server/certificate'.")
 	RootCmd.PersistentFlags().StringVarP(&opts.RegistryMirror, "registry-mirror", "", "", "Registry mirror to use has pull-through cache instead of docker.io.")
 	RootCmd.PersistentFlags().BoolVarP(&opts.WhitelistVarRun, "whitelist-var-run", "", true, "Ignore /var/run directory when taking image snapshot. Set it to false to preserve /var/run/ in destination image. (Default true).")
+	RootCmd.PersistentFlags().VarP(&opts.Labels, "label", "", "Set metadata for an image. Set it repeatedly for multiple labels.")
 }
 
 // addHiddenFlags marks certain flags as hidden from the executor help text

integration/integration_test.go

@@ -309,6 +309,49 @@ func TestBuildViaRegistryMirror(t *testing.T) {
 	checkContainerDiffOutput(t, diff, expected)
 }
 
+func TestBuildWithLabels(t *testing.T) {
+	repo := getGitRepo()
+	dockerfile := "integration/dockerfiles/Dockerfile_test_label"
+
+	testLabel := "mylabel=myvalue"
+
+	// Build with docker
+	dockerImage := GetDockerImage(config.imageRepo, "Dockerfile_test_label:mylabel")
+	dockerCmd := exec.Command("docker",
+		append([]string{"build",
+			"-t", dockerImage,
+			"-f", dockerfile,
+			"--label", testLabel,
+			repo})...)
+	out, err := RunCommandWithoutTest(dockerCmd)
+	if err != nil {
+		t.Errorf("Failed to build image %s with docker command %q: %s %s", dockerImage, dockerCmd.Args, err, string(out))
+	}
+
+	// Build with kaniko
+	kanikoImage := GetKanikoImage(config.imageRepo, "Dockerfile_test_label:mylabel")
+	dockerRunFlags := []string{"run", "--net=host"}
+	dockerRunFlags = addServiceAccountFlags(dockerRunFlags, config.serviceAccount)
+	dockerRunFlags = append(dockerRunFlags, ExecutorImage,
+		"-f", dockerfile,
+		"-d", kanikoImage,
+		"--label", testLabel,
+		"-c", fmt.Sprintf("git://%s", repo),
+	)
+
+	kanikoCmd := exec.Command("docker", dockerRunFlags...)
+
+	out, err = RunCommandWithoutTest(kanikoCmd)
+	if err != nil {
+		t.Errorf("Failed to build image %s with kaniko command %q: %v %s", dockerImage, kanikoCmd.Args, err, string(out))
+	}
+
+	diff := containerDiff(t, daemonPrefix+dockerImage, kanikoImage, "--no-cache")
+
+	expected := fmt.Sprintf(emptyContainerDiff, dockerImage, kanikoImage, dockerImage, kanikoImage)
+	checkContainerDiffOutput(t, diff, expected)
+}
+
 func TestLayers(t *testing.T) {
 	offset := map[string]int{
 		"Dockerfile_test_add":     12,

pkg/config/options.go

@@ -43,6 +43,7 @@ type KanikoOptions struct {
 	Destinations            multiArg
 	BuildArgs               multiArg
 	InsecureRegistries      multiArg
+	Labels                  multiArg
 	SkipTLSVerifyRegistries multiArg
 	RegistriesCertificates  keyValueArg
 	Insecure                bool

pkg/executor/build.go

@@ -21,6 +21,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/google/go-containerregistry/pkg/v1/partial"
@@ -82,7 +83,7 @@ func newStageBuilder(opts *config.KanikoOptions, stage config.KanikoStage, cross
 		return nil, err
 	}
 
-	imageConfig, err := initializeConfig(sourceImage)
+	imageConfig, err := initializeConfig(sourceImage, opts)
 	if err != nil {
 		return nil, err
 	}
@@ -134,7 +135,7 @@ func newStageBuilder(opts *config.KanikoOptions, stage config.KanikoStage, cross
 	return s, nil
 }
 
-func initializeConfig(img partial.WithConfigFile) (*v1.ConfigFile, error) {
+func initializeConfig(img partial.WithConfigFile, opts *config.KanikoOptions) (*v1.ConfigFile, error) {
 	imageConfig, err := img.ConfigFile()
 	if err != nil {
 		return nil, err
@@ -143,6 +144,25 @@ func initializeConfig(img partial.WithConfigFile) (*v1.ConfigFile, error) {
 	if imageConfig.Config.Env == nil {
 		imageConfig.Config.Env = constants.ScratchEnvVars
 	}
+
+	if opts == nil {
+		return imageConfig, nil
+	}
+
+	if l := len(opts.Labels); l > 0 {
+		if imageConfig.Config.Labels == nil {
+			imageConfig.Config.Labels = make(map[string]string)
+		}
+		for _, label := range opts.Labels {
+			parts := strings.SplitN(label, "=", 2)
+			if len(parts) != 2 {
+				return nil, fmt.Errorf("labels must be of the form key=value, got %s", label)
+			}
+
+			imageConfig.Config.Labels[parts[0]] = parts[1]
+		}
+	}
+
 	return imageConfig, nil
 }
 
@@ -484,7 +504,7 @@ func CalculateDependencies(opts *config.KanikoOptions) (map[int][]string, error)
 				return nil, err
 			}
 		}
-		cfg, err := initializeConfig(image)
+		cfg, err := initializeConfig(image, opts)
 		if err != nil {
 			return nil, err
 		}

pkg/executor/build_test.go

@@ -462,7 +462,7 @@ func TestInitializeConfig(t *testing.T) {
 			t.Errorf("error seen when running test %s", err)
 			t.Fail()
 		}
-		actual, _ := initializeConfig(img)
+		actual, _ := initializeConfig(img, nil)
 		testutil.CheckDeepEqual(t, tt.expected, actual.Config)
 	}
 }