Merge pull request #22508 from Microsoft/jjh/arg

Windows: Support ARG in builder

builder/dockerfile/evaluator_windows.go

@@ -6,7 +6,7 @@ import "fmt"
 // a command not supported on the platform.
 func platformSupports(command string) error {
 	switch command {
-	case "user", "stopsignal", "arg":
+	case "user", "stopsignal":
 		return fmt.Errorf("The daemon on this platform does not support the command '%s'", command)
 	}
 	return nil

container/container_windows.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/docker/docker/utils"
 	"github.com/docker/docker/volume"
 	containertypes "github.com/docker/engine-api/types/container"
 )
@@ -30,8 +31,10 @@ type ExitStatus struct {
 
 // CreateDaemonEnvironment creates a new environment variable slice for this container.
 func (container *Container) CreateDaemonEnvironment(linkedEnv []string) []string {
-	// On Windows, nothing to link. Just return the container environment.
-	return container.Config.Env
+	// because the env on the container can override certain default values
+	// we need to replace the 'env' keys where they match and append anything
+	// else.
+	return utils.ReplaceOrAppendEnvValues(linkedEnv, container.Config.Env)
 }
 
 // UnmountIpcMounts unmount Ipc related mounts.

integration-cli/docker_cli_build_test.go

@@ -6171,17 +6171,24 @@ func (s *DockerSuite) TestBuildStopSignal(c *check.C) {
 }
 
 func (s *DockerSuite) TestBuildBuildTimeArg(c *check.C) {
-	testRequires(c, DaemonIsLinux) // Windows does not support ARG
 	imgName := "bldargtest"
 	envKey := "foo"
 	envVal := "bar"
-	args := []string{
-		"--build-arg", fmt.Sprintf("%s=%s", envKey, envVal),
+	args := []string{"--build-arg", fmt.Sprintf("%s=%s", envKey, envVal)}
+	var dockerfile string
+	if daemonPlatform == "windows" {
+		// Bugs in Windows busybox port - use the default base image and native cmd stuff
+		dockerfile = fmt.Sprintf(`FROM `+minimalBaseImage()+`
+			ARG %s
+			RUN echo %%%s%%
+			CMD setlocal enableextensions && if defined %s (echo %%%s%%)`, envKey, envKey, envKey, envKey)
+	} else {
+		dockerfile = fmt.Sprintf(`FROM busybox
+			ARG %s
+			RUN echo $%s
+			CMD echo $%s`, envKey, envKey, envKey)
+
 	}
-	dockerfile := fmt.Sprintf(`FROM busybox
-		ARG %s
-		RUN echo $%s
-		CMD echo $%s`, envKey, envKey, envKey)
 
 	if _, out, err := buildImageWithOut(imgName, dockerfile, true, args...); err != nil || !strings.Contains(out, envVal) {
 		if err != nil {
@@ -6191,7 +6198,9 @@ func (s *DockerSuite) TestBuildBuildTimeArg(c *check.C) {
 	}
 
 	containerName := "bldargCont"
-	if out, _ := dockerCmd(c, "run", "--name", containerName, imgName); out != "\n" {
+	out, _ := dockerCmd(c, "run", "--name", containerName, imgName)
+	out = strings.Trim(out, " \r\n'")
+	if out != "" {
 		c.Fatalf("run produced invalid output: %q, expected empty string", out)
 	}
 }