Merge pull request #1175 from caarlos0/sub

feat: allow a subdir within a context

README.md

@@ -432,6 +432,12 @@ If `--destination=gcr.io/kaniko-project/test`, then cached layers will be stored
 
 _This flag must be used in conjunction with the `--cache=true` flag._
 
+#### --context-sub-path
+
+Set a sub path within the given `--context`.
+
+Its particularly useful when your context is, for example, a git repository,
+and you want to build one of its subfolders instead of the root folder.
 
 #### --digest-file
 

cmd/executor/cmd/root.go

@@ -40,6 +40,7 @@ import (
 
 var (
 	opts       = &config.KanikoOptions{}
+	ctxSubPath string
 	force      bool
 	logLevel   string
 	logFormat  string
@@ -131,6 +132,7 @@ var RootCmd = &cobra.Command{
 func addKanikoOptionsFlags() {
 	RootCmd.PersistentFlags().StringVarP(&opts.DockerfilePath, "dockerfile", "f", "Dockerfile", "Path to the dockerfile to be built.")
 	RootCmd.PersistentFlags().StringVarP(&opts.SrcContext, "context", "c", "/workspace/", "Path to the dockerfile build context.")
+	RootCmd.PersistentFlags().StringVarP(&ctxSubPath, "context-sub-path", "", "", "Sub path within the given context.")
 	RootCmd.PersistentFlags().StringVarP(&opts.Bucket, "bucket", "b", "", "Name of the GCS bucket from which to access build context as tarball.")
 	RootCmd.PersistentFlags().VarP(&opts.Destinations, "destination", "d", "Registry the final image should be pushed to. Set it repeatedly for multiple destinations.")
 	RootCmd.PersistentFlags().StringVarP(&opts.SnapshotMode, "snapshotMode", "", "full", "Change the file attributes inspected during snapshotting")
@@ -259,6 +261,12 @@ func resolveSourceContext() error {
 	if err != nil {
 		return err
 	}
+	if ctxSubPath != "" {
+		opts.SrcContext = filepath.Join(opts.SrcContext, ctxSubPath)
+		if _, err := os.Stat(opts.SrcContext); os.IsNotExist(err) {
+			return err
+		}
+	}
 	logrus.Debugf("Build context located at %s", opts.SrcContext)
 	return nil
 }

integration/integration_test.go

@@ -260,6 +260,50 @@ func TestGitBuildcontext(t *testing.T) {
 	checkContainerDiffOutput(t, diff, expected)
 }
 
+func TestGitBuildcontextSubPath(t *testing.T) {
+	repo := getGitRepo()
+	dockerfile := "Dockerfile_test_run_2"
+
+	// Build with docker
+	dockerImage := GetDockerImage(config.imageRepo, "Dockerfile_test_git")
+	dockerCmd := exec.Command("docker",
+		append([]string{
+			"build",
+			"-t", dockerImage,
+			"-f", dockerfile,
+			repo + ":" + filepath.Join(integrationPath, dockerfilesPath),
+		})...)
+	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_git")
+	dockerRunFlags := []string{"run", "--net=host"}
+	dockerRunFlags = addServiceAccountFlags(dockerRunFlags, config.serviceAccount)
+	dockerRunFlags = append(
+		dockerRunFlags,
+		ExecutorImage,
+		"-f", dockerfile,
+		"-d", kanikoImage,
+		"-c", fmt.Sprintf("git://%s", repo),
+		"--context-sub-path", filepath.Join(integrationPath, dockerfilesPath),
+	)
+
+	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 TestBuildViaRegistryMirror(t *testing.T) {
 	repo := getGitRepo()
 	dockerfile := "integration/dockerfiles/Dockerfile_registry_mirror"