builder: fix copy —from conflict with force pull

components/engine/daemon/build.go

@@ -1,6 +1,8 @@
 package daemon
 
 import (
+	"io"
+
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/distribution/reference"
 	"github.com/docker/docker/api/types"
@@ -12,7 +14,6 @@ import (
 	"github.com/docker/docker/registry"
 	"github.com/pkg/errors"
 	"golang.org/x/net/context"
-	"io"
 )
 
 type releaseableLayer struct {
@@ -104,13 +105,19 @@ func (daemon *Daemon) pullForBuilder(ctx context.Context, name string, authConfi
 // Every call to GetImageAndReleasableLayer MUST call releasableLayer.Release() to prevent
 // leaking of layers.
 func (daemon *Daemon) GetImageAndReleasableLayer(ctx context.Context, refOrID string, opts backend.GetImageAndLayerOptions) (builder.Image, builder.ReleaseableLayer, error) {
-	if !opts.ForcePull {
-		image, _ := daemon.GetImage(refOrID)
+	id, _ := daemon.GetImageID(refOrID)
+	refIsID := id.String() == refOrID // detect if ref is an ID to skip pulling
+
+	if refIsID || !opts.ForcePull {
+		image, err := daemon.GetImage(refOrID)
 		// TODO: shouldn't we error out if error is different from "not found" ?
 		if image != nil {
 			layer, err := newReleasableLayerForImage(image, daemon.layerStore)
 			return image, layer, err
 		}
+		if refIsID {
+			return nil, nil, err
+		}
 	}
 
 	image, err := daemon.pullForBuilder(ctx, refOrID, opts.AuthConfig, opts.Output)

components/engine/integration-cli/docker_api_build_test.go

@@ -5,11 +5,13 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"net/http"
 	"regexp"
 	"strings"
 
+	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/integration-cli/checker"
 	"github.com/docker/docker/integration-cli/cli/build/fakecontext"
 	"github.com/docker/docker/integration-cli/cli/build/fakegit"
@@ -367,6 +369,44 @@ func (s *DockerSuite) TestBuildAddRemoteNoDecompress(c *check.C) {
 	assert.Contains(c, string(out), "Successfully built")
 }
 
+func (s *DockerRegistrySuite) TestBuildCopyFromForcePull(c *check.C) {
+	client, err := request.NewClient()
+	require.NoError(c, err)
+
+	repoName := fmt.Sprintf("%v/dockercli/busybox", privateRegistryURL)
+	// tag the image to upload it to the private registry
+	err = client.ImageTag(context.TODO(), "busybox", repoName)
+	assert.Nil(c, err)
+	// push the image to the registry
+	rc, err := client.ImagePush(context.TODO(), repoName, types.ImagePushOptions{RegistryAuth: "{}"})
+	assert.Nil(c, err)
+	_, err = io.Copy(ioutil.Discard, rc)
+	assert.Nil(c, err)
+
+	dockerfile := fmt.Sprintf(`
+		FROM %s AS foo
+		RUN touch abc
+		FROM %s
+		COPY --from=foo /abc /
+		`, repoName, repoName)
+
+	ctx := fakecontext.New(c, "",
+		fakecontext.WithDockerfile(dockerfile),
+	)
+	defer ctx.Close()
+
+	res, body, err := request.Post(
+		"/build?pull=1",
+		request.RawContent(ctx.AsTarReader(c)),
+		request.ContentType("application/x-tar"))
+	require.NoError(c, err)
+	assert.Equal(c, http.StatusOK, res.StatusCode)
+
+	out, err := testutil.ReadBody(body)
+	require.NoError(c, err)
+	assert.Contains(c, string(out), "Successfully built")
+}
+
 type buildLine struct {
 	Stream string
 	Aux    struct {