support `changes` in commit job

In addition to config env, `commit` now will also accepts a `changes` env which
is a string contains new-line separated Dockerfile instructions.
`commit` will evaluate `changes` into `runconfig.Config` and merge it with
`config` env, and then finally commit a new image with the changed config

Docker-DCO-1.1-Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com> (github: dqminh)

Docker-DCO-1.1-Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com> (github: rhatdan)

daemon/commit.go

@@ -1,6 +1,9 @@
 package daemon
 
 import (
+	"bytes"
+	"encoding/json"
+
 	"github.com/docker/docker/engine"
 	"github.com/docker/docker/image"
 	"github.com/docker/docker/runconfig"
@@ -18,11 +21,21 @@ func (daemon *Daemon) ContainerCommit(job *engine.Job) engine.Status {
 	}
 
 	var (
-		config    = container.Config
-		newConfig runconfig.Config
+		config       = container.Config
+		stdoutBuffer = bytes.NewBuffer(nil)
+		newConfig    runconfig.Config
 	)
 
-	if err := job.GetenvJson("config", &newConfig); err != nil {
+	buildConfigJob := daemon.eng.Job("build_config")
+	buildConfigJob.Stdout.Add(stdoutBuffer)
+	buildConfigJob.Setenv("changes", job.Getenv("changes"))
+	// FIXME this should be remove when we remove deprecated config param
+	buildConfigJob.Setenv("config", job.Getenv("config"))
+
+	if err := buildConfigJob.Run(); err != nil {
+		return job.Error(err)
+	}
+	if err := json.NewDecoder(stdoutBuffer).Decode(&newConfig); err != nil {
 		return job.Error(err)
 	}
 

integration-cli/docker_cli_commit_test.go

@@ -202,3 +202,36 @@ func TestCommitWithHostBindMount(t *testing.T) {
 
 	logDone("commit - commit bind mounted file")
 }
+
+func TestCommitChange(t *testing.T) {
+	defer deleteAllContainers()
+	cmd(t, "run", "--name", "test", "busybox", "true")
+
+	cmd := exec.Command(dockerBinary, "commit",
+		"--change", "EXPOSE 8080",
+		"--change", "ENV DEBUG true",
+		"test", "test-commit")
+	imageId, _, err := runCommandWithOutput(cmd)
+	if err != nil {
+		t.Fatal(imageId, err)
+	}
+	imageId = strings.Trim(imageId, "\r\n")
+	defer deleteImages(imageId)
+
+	expected := map[string]string{
+		"Config.ExposedPorts": "map[8080/tcp:map[]]",
+		"Config.Env":          "[DEBUG=true PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin]",
+	}
+
+	for conf, value := range expected {
+		res, err := inspectField(imageId, conf)
+		if err != nil {
+			t.Errorf("failed to get value %s, error: %s", conf, err)
+		}
+		if res != value {
+			t.Errorf("%s('%s'), expected %s", conf, res, value)
+		}
+	}
+
+	logDone("commit - commit --change")
+}