From 32de0343adf02f1539a84bb1b92fe386d53b36b3 Mon Sep 17 00:00:00 2001
From: dlorenc <lorenc.d@gmail.com>
Date: Sat, 11 Aug 2018 11:17:29 -0700
Subject: [PATCH] Add the --target flag as a parameter to the docker builder.

---
 examples/annotated-skaffold.yaml       |  2 +
 pkg/skaffold/build/local/docker.go     |  3 --
 pkg/skaffold/docker/image.go           |  9 ++++
 pkg/skaffold/docker/image_test.go      | 68 +++++++++++++++++++++-----
 pkg/skaffold/schema/v1alpha2/config.go |  1 +
 5 files changed, 69 insertions(+), 14 deletions(-)

diff --git a/examples/annotated-skaffold.yaml b/examples/annotated-skaffold.yaml
index 89c139cc607..0742ae321ab 100644
--- a/examples/annotated-skaffold.yaml
+++ b/examples/annotated-skaffold.yaml
@@ -53,6 +53,8 @@ build:
       cacheFrom:
       - image1
       - image2
+      # Dockerfile target name to build.
+      target: stageName
 
     # bazel requires bazel CLI to be installed and the artifacts sources to
     # contain Bazel configuration files.
diff --git a/pkg/skaffold/build/local/docker.go b/pkg/skaffold/build/local/docker.go
index ebb68abf67e..5ff2eb3ddeb 100644
--- a/pkg/skaffold/build/local/docker.go
+++ b/pkg/skaffold/build/local/docker.go
@@ -40,9 +40,6 @@ func (b *Builder) buildDocker(ctx context.Context, out io.Writer, workspace stri
 
 		args := []string{"build", workspace, "--file", dockerfilePath, "-t", initialTag}
 		args = append(args, docker.GetBuildArgs(a)...)
-		for _, from := range a.CacheFrom {
-			args = append(args, "--cache-from", from)
-		}
 
 		cmd := exec.Command("docker", args...)
 		if b.cfg.UseBuildkit {
diff --git a/pkg/skaffold/docker/image.go b/pkg/skaffold/docker/image.go
index 799c69b5205..44365a0d530 100644
--- a/pkg/skaffold/docker/image.go
+++ b/pkg/skaffold/docker/image.go
@@ -66,6 +66,7 @@ func BuildArtifact(ctx context.Context, out io.Writer, cli APIClient, workspace
 		BuildArgs:   a.BuildArgs,
 		CacheFrom:   a.CacheFrom,
 		AuthConfigs: authConfigs,
+		Target:      a.Target,
 	})
 	if err != nil {
 		return errors.Wrap(err, "docker build")
@@ -194,5 +195,13 @@ func GetBuildArgs(a *v1alpha2.DockerArtifact) []string {
 		}
 	}
 
+	for _, from := range a.CacheFrom {
+		args = append(args, "--cache-from", from)
+	}
+
+	if a.Target != "" {
+		args = append(args, "--target", a.Target)
+	}
+
 	return args
 }
diff --git a/pkg/skaffold/docker/image_test.go b/pkg/skaffold/docker/image_test.go
index e147fc1bfb5..50d15c1799d 100644
--- a/pkg/skaffold/docker/image_test.go
+++ b/pkg/skaffold/docker/image_test.go
@@ -171,18 +171,64 @@ func TestDigest(t *testing.T) {
 }
 
 func TestGetBuildArgs(t *testing.T) {
-	artifact := &v1alpha2.DockerArtifact{
-		BuildArgs: map[string]*string{
-			"key1": util.StringPtr("value1"),
-			"key2": nil,
+	type args struct {
+		a *v1alpha2.DockerArtifact
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			name: "build args",
+			args: args{
+				a: &v1alpha2.DockerArtifact{
+					BuildArgs: map[string]*string{
+						"key1": util.StringPtr("value1"),
+						"key2": nil,
+					},
+				},
+			},
+			want: []string{"--build-arg", "key1=value1", "--build-arg", "key2"},
+		},
+		{
+			name: "cache from",
+			args: args{
+				a: &v1alpha2.DockerArtifact{
+					CacheFrom: []string{"gcr.io/foo/bar", "baz:latest"},
+				},
+			},
+			want: []string{"--cache-from", "gcr.io/foo/bar", "--cache-from", "baz:latest"},
+		},
+		{
+			name: "target",
+			args: args{
+				a: &v1alpha2.DockerArtifact{
+					Target: "stage1",
+				},
+			},
+			want: []string{"--target", "stage1"},
+		},
+		{
+			name: "all",
+			args: args{
+				a: &v1alpha2.DockerArtifact{
+					BuildArgs: map[string]*string{
+						"key1": util.StringPtr("value1"),
+					},
+					CacheFrom: []string{"foo"},
+					Target:    "stage1",
+				},
+			},
+			want: []string{"--build-arg", "key1=value1", "--cache-from", "foo", "--target", "stage1"},
 		},
 	}
-
-	arg := GetBuildArgs(artifact)
-	expected := []string{"--build-arg", "key1=value1", "--build-arg", "key2"}
-
-	if diff := cmp.Diff(arg, expected); diff != "" {
-		t.Errorf("%T differ (-got, +want): %s", expected, diff)
-		return
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := GetBuildArgs(tt.args.a)
+			if diff := cmp.Diff(result, tt.want); diff != "" {
+				t.Errorf("%T differ (-got, +want): %s", tt.want, diff)
+			}
+		})
 	}
 }
diff --git a/pkg/skaffold/schema/v1alpha2/config.go b/pkg/skaffold/schema/v1alpha2/config.go
index c2b2fea0b69..0e8506e6fc1 100644
--- a/pkg/skaffold/schema/v1alpha2/config.go
+++ b/pkg/skaffold/schema/v1alpha2/config.go
@@ -210,6 +210,7 @@ type DockerArtifact struct {
 	DockerfilePath string             `yaml:"dockerfilePath,omitempty"`
 	BuildArgs      map[string]*string `yaml:"buildArgs,omitempty"`
 	CacheFrom      []string           `yaml:"cacheFrom,omitempty"`
+	Target         string             `yaml:"target,omitempty"`
 }
 
 type BazelArtifact struct {