bake: fix dockerfile and context defaults

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

bake/bake.go

@@ -109,9 +109,9 @@ func (c Config) setOverrides(v []string) error {
 
 		switch keys[1] {
 		case "context":
-			t.Context = parts[1]
+			t.Context = &parts[1]
 		case "dockerfile":
-			t.Dockerfile = parts[1]
+			t.Dockerfile = &parts[1]
 		case "args":
 			if len(keys) != 3 {
 				return errors.Errorf("invalid key %s, args requires name", parts[0])
@@ -170,7 +170,19 @@ func (c Config) group(name string, visited map[string]struct{}) []string {
 }
 
 func (c Config) ResolveTarget(name string) (*Target, error) {
-	return c.target(name, map[string]struct{}{})
+	t, err := c.target(name, map[string]struct{}{})
+	if err != nil {
+		return nil, err
+	}
+	if t.Context == nil {
+		s := "."
+		t.Context = &s
+	}
+	if t.Dockerfile == nil {
+		s := "Dockerfile"
+		t.Dockerfile = &s
+	}
+	return t, nil
 }
 
 func (c Config) target(name string, visited map[string]struct{}) (*Target, error) {
@@ -205,8 +217,8 @@ type Group struct {
 
 type Target struct {
 	Inherits   []string          `json:"inherits,omitempty"`
-	Context    string            `json:"context,omitempty"`
-	Dockerfile string            `json:"dockerfile,omitempty"`
+	Context    *string           `json:"context,omitempty"`
+	Dockerfile *string           `json:"dockerfile,omitempty"`
 	Args       map[string]string `json:"args,omitempty"`
 	Labels     map[string]string `json:"labels,omitempty"`
 	Tags       []string          `json:"tags,omitempty"`
@@ -238,17 +250,26 @@ func TargetsToBuildOpt(m map[string]Target) (map[string]build.Options, error) {
 }
 
 func toBuildOpt(t Target) (*build.Options, error) {
-	if t.Context == "-" {
+	if v := t.Context; v != nil && *v == "-" {
 		return nil, errors.Errorf("context from stdin not allowed in bake")
 	}
-	if t.Dockerfile == "-" {
+	if v := t.Dockerfile; v != nil && *v == "-" {
 		return nil, errors.Errorf("dockerfile from stdin not allowed in bake")
 	}
 
+	contextPath := "."
+	if t.Context != nil {
+		contextPath = *t.Context
+	}
+	dockerfilePath := "Dockerfile"
+	if t.Dockerfile != nil {
+		dockerfilePath = *t.Dockerfile
+	}
+
 	bo := &build.Options{
 		Inputs: build.Inputs{
-			ContextPath:    t.Context,
-			DockerfilePath: t.Dockerfile,
+			ContextPath:    contextPath,
+			DockerfilePath: dockerfilePath,
 		},
 		Tags:      t.Tags,
 		BuildArgs: t.Args,
@@ -295,17 +316,14 @@ func toBuildOpt(t Target) (*build.Options, error) {
 }
 
 func defaultTarget() Target {
-	return Target{
-		Context:    ".",
-		Dockerfile: "Dockerfile",
-	}
+	return Target{}
 }
 
 func merge(t1, t2 Target) Target {
-	if t2.Context != "" {
+	if t2.Context != nil {
 		t1.Context = t2.Context
 	}
-	if t2.Dockerfile != "" {
+	if t2.Dockerfile != nil {
 		t1.Dockerfile = t2.Dockerfile
 	}
 	for k, v := range t2.Args {

bake/bake_test.go

@@ -0,0 +1,69 @@
+package bake
+
+import (
+	"context"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestReadTargets(t *testing.T) {
+	t.Parallel()
+	tmpdir, err := ioutil.TempDir("", "bake")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmpdir)
+
+	fp := filepath.Join(tmpdir, "config.hcl")
+	err = ioutil.WriteFile(fp, []byte(`
+target "dep" {
+}
+
+target "webapp" {
+	dockerfile = "Dockerfile.webapp"
+	inherits = ["dep"]
+}`), 0600)
+	require.NoError(t, err)
+
+	ctx := context.TODO()
+
+	m, err := ReadTargets(ctx, []string{fp}, []string{"webapp"}, nil)
+	require.NoError(t, err)
+
+	require.Equal(t, "Dockerfile.webapp", *m["webapp"].Dockerfile)
+	require.Equal(t, ".", *m["webapp"].Context)
+}
+
+func TestReadTargetsCompose(t *testing.T) {
+	t.Parallel()
+	tmpdir, err := ioutil.TempDir("", "bake")
+	require.NoError(t, err)
+	defer os.RemoveAll(tmpdir)
+
+	fp := filepath.Join(tmpdir, "docker-compose.yml")
+	err = ioutil.WriteFile(fp, []byte(`
+version: "3"
+
+services:
+  db:
+    build: .
+    command: ./entrypoint.sh
+    image: docker.io/tonistiigi/db
+  webapp:
+    build:
+      dockerfile: Dockerfile.webapp
+      args:
+        buildno: 1
+`), 0600)
+	require.NoError(t, err)
+
+	ctx := context.TODO()
+
+	m, err := ReadTargets(ctx, []string{fp}, []string{"default"}, nil)
+	require.NoError(t, err)
+
+	require.Equal(t, "Dockerfile.webapp", *m["webapp"].Dockerfile)
+	require.Equal(t, ".", *m["webapp"].Context)
+}

bake/compose.go

@@ -34,9 +34,19 @@ func ParseCompose(dt []byte) (*Config, error) {
 
 		for _, s := range cfg.Services {
 			g.Targets = append(g.Targets, s.Name)
+			var contextPathP *string
+			if s.Build.Context != "" {
+				contextPath := s.Build.Context
+				contextPathP = &contextPath
+			}
+			var dockerfilePathP *string
+			if s.Build.Dockerfile != "" {
+				dockerfilePath := s.Build.Dockerfile
+				dockerfilePathP = &dockerfilePath
+			}
 			t := Target{
-				Context:    s.Build.Context,
-				Dockerfile: s.Build.Dockerfile,
+				Context:    contextPathP,
+				Dockerfile: dockerfilePathP,
 				Labels:     s.Build.Labels,
 				Args:       toMap(s.Build.Args),
 				CacheFrom:  s.Build.CacheFrom,

bake/compose_test.go

@@ -32,10 +32,10 @@ services:
 	require.Equal(t, []string{"db", "webapp"}, c.Group["default"].Targets)
 
 	require.Equal(t, 2, len(c.Target))
-	require.Equal(t, "./db", c.Target["db"].Context)
+	require.Equal(t, "./db", *c.Target["db"].Context)
 
-	require.Equal(t, "./dir", c.Target["webapp"].Context)
-	require.Equal(t, "Dockerfile-alternate", c.Target["webapp"].Dockerfile)
+	require.Equal(t, "./dir", *c.Target["webapp"].Context)
+	require.Equal(t, "Dockerfile-alternate", *c.Target["webapp"].Dockerfile)
 	require.Equal(t, 1, len(c.Target["webapp"].Args))
 	require.Equal(t, "123", c.Target["webapp"].Args["buildno"])
 }

bake/hcl_test.go

@@ -47,7 +47,7 @@ func TestParseHCL(t *testing.T) {
 	require.Equal(t, []string{"db", "webapp"}, c.Group["default"].Targets)
 
 	require.Equal(t, 4, len(c.Target))
-	require.Equal(t, "./db", c.Target["db"].Context)
+	require.Equal(t, "./db", *c.Target["db"].Context)
 
 	require.Equal(t, 1, len(c.Target["webapp"].Args))
 	require.Equal(t, "123", c.Target["webapp"].Args["buildno"])

build/build.go

@@ -420,7 +420,7 @@ func LoadInputs(inp Inputs, target *client.SolveOpt) (func(), error) {
 }
 
 func notSupported(d driver.Driver, f driver.Feature) error {
-	return errors.Errorf("%s feature is currently not supported for %s driver. Please switch to a different driver (eg. \"docker buildx create\")", f, d.Factory().Name())
+	return errors.Errorf("%s feature is currently not supported for %s driver. Please switch to a different driver (eg. \"docker buildx create --use\")", f, d.Factory().Name())
 }
 
 func newDockerLoader(ctx context.Context, d DockerAPI, name string, mw *progress.MultiWriter) (io.WriteCloser, func(), error) {