@@ -77,7 +77,11 @@ func (b *BuilderClient) CmdRun(args string) error {

 	if err != nil {

 		return err

 	}

+

+	cmd, env := b.config.Cmd, b.config.Env

+	b.config.Cmd = nil

 	MergeConfig(b.config, config)

+

 	body, statusCode, err := b.cli.call("POST", "/images/getCache", &ApiImageConfig{Id: b.image, Config: b.config})

 	if err != nil {

 		if statusCode != 404 {

@@ -89,11 +93,16 @@ func (b *BuilderClient) CmdRun(args string) error {

 		if err := json.Unmarshal(body, apiId); err != nil {

 			return err

 		}

+		utils.Debugf("Use cached version")

 		b.image = apiId.Id

 		return nil

 	}

-	b.commit()

-	return nil

+	cid, err := b.run()

+	if err != nil {

+		return err

+	}

+	b.config.Cmd, b.config.Env = cmd, env

+	return b.commit(cid)

 }

 func (b *BuilderClient) CmdEnv(args string) error {

@@ -133,54 +142,80 @@ func (b *BuilderClient) CmdInsert(args string) error {

 	return fmt.Errorf("INSERT not implemented")

 }

-func (b *BuilderClient) commit() error {

-	if b.config.Cmd == nil || len(b.config.Cmd) < 1 {

-		b.config.Cmd = []string{"echo"}

+func (b *BuilderClient) run() (string, error) {

+	if b.image == "" {

+		return "", fmt.Errorf("Please provide a source image with `from` prior to run")

 	}

-

+	b.config.Image = b.image

 	body, _, err := b.cli.call("POST", "/containers/create", b.config)

 	if err != nil {

-		return err

+		return "", err

 	}

-	out := &ApiRun{}

-	err = json.Unmarshal(body, out)

-	if err != nil {

-		return err

+	apiRun := &ApiRun{}

+	if err := json.Unmarshal(body, apiRun); err != nil {

+		return "", err

 	}

-

-	for _, warning := range out.Warnings {

+	for _, warning := range apiRun.Warnings {

 		fmt.Fprintln(os.Stderr, "WARNING: ", warning)

 	}

 	//start the container

-	_, _, err = b.cli.call("POST", "/containers/"+out.Id+"/start", nil)

+	_, _, err = b.cli.call("POST", "/containers/"+apiRun.Id+"/start", nil)

 	if err != nil {

-		return err

+		return "", err

 	}

-	b.tmpContainers[out.Id] = struct{}{}

+	b.tmpContainers[apiRun.Id] = struct{}{}

 	// Wait for it to finish

-	_, _, err = b.cli.call("POST", "/containers/"+out.Id+"/wait", nil)

+	body, _, err = b.cli.call("POST", "/containers/"+apiRun.Id+"/wait", nil)

 	if err != nil {

-		return err

+		return "", err

+	}

+	apiWait := &ApiWait{}

+	if err := json.Unmarshal(body, apiWait); err != nil {

+		return "", err

+	}

+	if apiWait.StatusCode != 0 {

+		return "", fmt.Errorf("The command %v returned a non-zero code: %d", b.config.Cmd, apiWait.StatusCode)

+	}

+

+	return apiRun.Id, nil

+}

+

+func (b *BuilderClient) commit(id string) error {

+	if b.image == "" {

+		return fmt.Errorf("Please provide a source image with `from` prior to run")

+	}

+	b.config.Image = b.image

+

+	if id == "" {

+		cmd := b.config.Cmd

+		b.config.Cmd = []string{"true"}

+		if cid, err := b.run(); err != nil {

+			return err

+		} else {

+			id = cid

+		}

+		b.config.Cmd = cmd

 	}

 	// Commit the container

 	v := url.Values{}

-	v.Set("container", out.Id)

+	v.Set("container", id)

 	v.Set("author", b.maintainer)

-	body, _, err = b.cli.call("POST", "/commit?"+v.Encode(), b.config)

+

+	body, _, err := b.cli.call("POST", "/commit?"+v.Encode(), b.config)

 	if err != nil {

 		return err

 	}

 	apiId := &ApiId{}

-	err = json.Unmarshal(body, apiId)

-	if err != nil {

+	if err := json.Unmarshal(body, apiId); err != nil {

 		return err

 	}

 	b.tmpImages[apiId.Id] = struct{}{}

 	b.image = apiId.Id

+	b.needCommit = false

 	return nil

 }

@@ -221,7 +256,9 @@ func (b *BuilderClient) Build(dockerfile io.Reader) (string, error) {

 		fmt.Printf("===> %v\n", b.image)

 	}

 	if b.needCommit {

-		b.commit()

+		if err := b.commit(""); err != nil {

+			return "", err

+		}

 	}

 	if b.image != "" {

 		// The build is successful, keep the temporary containers and images