COPY file . after WORKDIR (now always created)

Signed-off-by: John Howard <jhoward@microsoft.com>

builder/builder.go

@@ -129,6 +129,8 @@ type Backend interface {
 	ContainerWait(containerID string, timeout time.Duration) (int, error)
 	// ContainerUpdateCmdOnBuild updates container.Path and container.Args
 	ContainerUpdateCmdOnBuild(containerID string, cmd []string) error
+	// ContainerCreateWorkdir creates the workdir (currently only used on Windows)
+	ContainerCreateWorkdir(containerID string) error
 
 	// ContainerCopy copies/extracts a source FileInfo to a destination path inside a container
 	// specified by a container object.

builder/dockerfile/dispatchers.go

@@ -18,6 +18,7 @@ import (
 
 	"github.com/Sirupsen/logrus"
 	"github.com/docker/docker/api"
+	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
 	"github.com/docker/docker/api/types/strslice"
 	"github.com/docker/docker/builder"
@@ -279,12 +280,26 @@ func workdir(b *Builder, args []string, attributes map[string]bool, original str
 		return err
 	}
 
-	// NOTE: You won't find the "mkdir" for the directory in here. Rather we
-	// just set the value in the image's runConfig.WorkingDir property
-	// and container.SetupWorkingDirectory() will create it automatically
-	// for us the next time the image is used to create a container.
+	// For performance reasons, we explicitly do a create/mkdir now
+	// This avoids having an unnecessary expensive mount/unmount calls
+	// (on Windows in particular) during each container create.
+	// Prior to 1.13, the mkdir was deferred and not executed at this step.
+	if b.disableCommit {
+		// Don't call back into the daemon if we're going through docker commit --change "WORKDIR /foo".
+		// We've already updated the runConfig and that's enough.
+		return nil
+	}
+	b.runConfig.Image = b.image
+	container, err := b.docker.ContainerCreate(types.ContainerCreateConfig{Config: b.runConfig}, true)
+	if err != nil {
+		return err
+	}
+	b.tmpContainers[container.ID] = struct{}{}
+	if err := b.docker.ContainerCreateWorkdir(container.ID); err != nil {
+		return err
+	}
 
-	return b.commit("", b.runConfig.Cmd, fmt.Sprintf("WORKDIR %v", b.runConfig.WorkingDir))
+	return b.commit(container.ID, b.runConfig.Cmd, "WORKDIR "+b.runConfig.WorkingDir)
 }
 
 // RUN some command yo

daemon/workdir.go

@@ -0,0 +1,21 @@
+package daemon
+
+// ContainerCreateWorkdir creates the working directory. This is solves the
+// issue arising from https://github.com/docker/docker/issues/27545,
+// which was initially fixed by https://github.com/docker/docker/pull/27884. But that fix
+// was too expensive in terms of performance on Windows. Instead,
+// https://github.com/docker/docker/pull/28514 introduces this new functionality
+// where the builder calls into the backend here to create the working directory.
+func (daemon *Daemon) ContainerCreateWorkdir(cID string) error {
+	container, err := daemon.GetContainer(cID)
+	if err != nil {
+		return err
+	}
+	err = daemon.Mount(container)
+	if err != nil {
+		return err
+	}
+	defer daemon.Unmount(container)
+	rootUID, rootGID := daemon.GetRemappedUIDGID()
+	return container.SetupWorkingDirectory(rootUID, rootGID)
+}

integration-cli/docker_cli_build_test.go

@@ -1878,8 +1878,8 @@ func (s *DockerSuite) TestBuildWindowsAddCopyPathProcessing(c *check.C) {
 			WORKDIR /wc2
 			ADD wc2 c:/wc2
 			WORKDIR c:/
-			RUN sh -c "[ $(cat c:/wc1) = 'hellowc1' ]"
-			RUN sh -c "[ $(cat c:/wc2) = 'worldwc2' ]"
+			RUN sh -c "[ $(cat c:/wc1/wc1) = 'hellowc1' ]"
+			RUN sh -c "[ $(cat c:/wc2/wc2) = 'worldwc2' ]"
 
 			# Trailing slash on COPY/ADD, Windows-style path.
 			WORKDIR /wd1
@@ -7283,3 +7283,31 @@ func (s *DockerSuite) TestBuildWindowsUser(c *check.C) {
 	}
 	c.Assert(strings.ToLower(out), checker.Contains, "username=user")
 }
+
+// Verifies if COPY file . when WORKDIR is set to a non-existing directory,
+// the directory is created and the file is copied into the directory,
+// as opposed to the file being copied as a file with the name of the
+// directory. Fix for 27545 (found on Windows, but regression good for Linux too).
+// Note 27545 was reverted in 28505, but a new fix was added subsequently in 28514.
+func (s *DockerSuite) TestBuildCopyFileDotWithWorkdir(c *check.C) {
+	name := "testbuildcopyfiledotwithworkdir"
+	ctx, err := fakeContext(`FROM busybox 
+WORKDIR /foo 
+COPY file . 
+RUN ["cat", "/foo/file"] 
+`,
+		map[string]string{})
+
+	if err != nil {
+		c.Fatal(err)
+	}
+	defer ctx.Close()
+
+	if err := ctx.Add("file", "content"); err != nil {
+		c.Fatal(err)
+	}
+
+	if _, err = buildImageFromContext(name, ctx, true); err != nil {
+		c.Fatal(err)
+	}
+}

integration-cli/docker_cli_commit_test.go

@@ -104,7 +104,6 @@ func (s *DockerSuite) TestCommitWithHostBindMount(c *check.C) {
 }
 
 func (s *DockerSuite) TestCommitChange(c *check.C) {
-	testRequires(c, DaemonIsLinux)
 	dockerCmd(c, "run", "--name", "test", "busybox", "true")
 
 	imageID, _ := dockerCmd(c, "commit",
@@ -122,12 +121,14 @@ func (s *DockerSuite) TestCommitChange(c *check.C) {
 		"test", "test-commit")
 	imageID = strings.TrimSpace(imageID)
 
+	prefix, slash := getPrefixAndSlashFromDaemonPlatform()
+	prefix = strings.ToUpper(prefix) // Force C: as that's how WORKDIR is normalised on Windows
 	expected := map[string]string{
 		"Config.ExposedPorts": "map[8080/tcp:{}]",
 		"Config.Env":          "[DEBUG=true test=1 PATH=/foo]",
 		"Config.Labels":       "map[foo:bar]",
 		"Config.Cmd":          "[/bin/sh]",
-		"Config.WorkingDir":   "/opt",
+		"Config.WorkingDir":   prefix + slash + "opt",
 		"Config.Entrypoint":   "[/bin/sh]",
 		"Config.User":         "testuser",
 		"Config.Volumes":      "map[/var/lib/docker:{}]",