builder/docker: StepRun tests

builder/docker/driver.go

@@ -6,4 +6,17 @@ package docker
 type Driver interface {
 	// Pull should pull down the given image.
 	Pull(image string) error
+
+	// StartContainer starts a container and returns the ID for that container,
+	// along with a potential error.
+	StartContainer(*ContainerConfig) (string, error)
+
+	// StopContainer forcibly stops a container.
+	StopContainer(id string) error
+}
+
+// ContainerConfig is the configuration used to start a container.
+type ContainerConfig struct {
+	Image   string
+	Volumes map[string]string
 }

builder/docker/driver_docker.go

@@ -1,8 +1,12 @@
 package docker
 
 import (
+	"bytes"
+	"fmt"
 	"github.com/mitchellh/packer/packer"
+	"log"
 	"os/exec"
+	"strings"
 )
 
 type DockerDriver struct {
@@ -13,3 +17,42 @@ func (d *DockerDriver) Pull(image string) error {
 	cmd := exec.Command("docker", "pull", image)
 	return runAndStream(cmd, d.Ui)
 }
+
+func (d *DockerDriver) StartContainer(config *ContainerConfig) (string, error) {
+	// Args that we're going to pass to Docker
+	args := []string{"run", "-d", "-i", "-t"}
+
+	if len(config.Volumes) > 0 {
+		volumes := make([]string, 0, len(config.Volumes))
+		for host, guest := range config.Volumes {
+			volumes = append(volumes, fmt.Sprintf("%s:%s", host, guest))
+		}
+
+		args = append(args, "-v", strings.Join(volumes, ","))
+	}
+
+	args = append(args, config.Image, "/bin/bash")
+
+	// Start the container
+	var stdout, stderr bytes.Buffer
+	cmd := exec.Command("docker", args...)
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	log.Printf("Starting container with args: %v", args)
+	if err := cmd.Start(); err != nil {
+		return "", err
+	}
+
+	log.Println("Waiting for container to finish starting")
+	if err := cmd.Wait(); err != nil {
+		return "", err
+	}
+
+	// Capture the container ID, which is alone on stdout
+	return strings.TrimSpace(stdout.String()), nil
+}
+
+func (d *DockerDriver) StopContainer(id string) error {
+	return exec.Command("docker", "kill", id).Run()
+}

builder/docker/driver_mock.go

@@ -2,10 +2,17 @@ package docker
 
 // MockDriver is a driver implementation that can be used for tests.
 type MockDriver struct {
-	PullError error
+	PullError  error
+	StartID    string
+	StartError error
+	StopError  error
 
-	PullCalled bool
+	PullCalled  bool
-	PullImage  string
+	PullImage   string
+	StartCalled bool
+	StartConfig *ContainerConfig
+	StopCalled  bool
+	StopID      string
 }
 
 func (d *MockDriver) Pull(image string) error {
@@ -13,3 +20,15 @@ func (d *MockDriver) Pull(image string) error {
 	d.PullImage = image
 	return d.PullError
 }
+
+func (d *MockDriver) StartContainer(config *ContainerConfig) (string, error) {
+	d.StartCalled = true
+	d.StartConfig = config
+	return d.StartID, d.StartError
+}
+
+func (d *MockDriver) StopContainer(id string) error {
+	d.StopCalled = true
+	d.StopID = id
+	return d.StopError
+}

builder/docker/driver_mock_test.go

@@ -0,0 +1,7 @@
+package docker
+
+import "testing"
+
+func TestMockDriver_impl(t *testing.T) {
+	var _ Driver = new(MockDriver)
+}

builder/docker/drover_docker_test.go

@@ -0,0 +1,7 @@
+package docker
+
+import "testing"
+
+func TestDockerDriver_impl(t *testing.T) {
+	var _ Driver = new(DockerDriver)
+}

builder/docker/step_run.go

@@ -1,13 +1,9 @@
 package docker
 
 import (
-	"bytes"
 	"fmt"
 	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
-	"log"
-	"os/exec"
-	"strings"
 )
 
 type StepRun struct {
@@ -16,47 +12,30 @@ type StepRun struct {
 
 func (s *StepRun) Run(state multistep.StateBag) multistep.StepAction {
 	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(Driver)
 	tempDir := state.Get("temp_dir").(string)
 	ui := state.Get("ui").(packer.Ui)
 
-	ui.Say("Starting docker container with /bin/bash")
+	runConfig := ContainerConfig{
-
+		Image: config.Image,
-	// Args that we're going to pass to Docker
+		Volumes: map[string]string{
-	args := []string{
+			tempDir: "/packer-files",
-		"run",
+		},
-		"-d", "-i", "-t",
-		"-v", fmt.Sprintf("%s:/packer-files", tempDir),
-		config.Image,
-		"/bin/bash",
 	}
 
-	// Start the container
+	ui.Say("Starting docker container with /bin/bash")
-	var stdout, stderr bytes.Buffer
+	containerId, err := driver.StartContainer(&runConfig)
-	cmd := exec.Command("docker", args...)
+	if err != nil {
-	cmd.Stdout = &stdout
-	cmd.Stderr = &stderr
-
-	log.Printf("Starting container with args: %v", args)
-	if err := cmd.Start(); err != nil {
 		err := fmt.Errorf("Error running container: %s", err)
 		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
 
-	if err := cmd.Wait(); err != nil {
+	// Save the container ID
-		err := fmt.Errorf("Error running container: %s\nStderr: %s",
+	s.containerId = containerId
-			err, stderr.String())
-		state.Put("error", err)
-		ui.Error(err.Error())
-		return multistep.ActionHalt
-	}
-
-	// Capture the container ID, which is alone on stdout
-	s.containerId = strings.TrimSpace(stdout.String())
-	ui.Message(fmt.Sprintf("Container ID: %s", s.containerId))
-
 	state.Put("container_id", s.containerId)
+	ui.Message(fmt.Sprintf("Container ID: %s", s.containerId))
 	return multistep.ActionContinue
 }
 
@@ -68,5 +47,9 @@ func (s *StepRun) Cleanup(state multistep.StateBag) {
 	// Kill the container. We don't handle errors because errors usually
 	// just mean that the container doesn't exist anymore, which isn't a
 	// big deal.
-	exec.Command("docker", "kill", s.containerId).Run()
+	driver := state.Get("driver").(Driver)
+	driver.StopContainer(s.containerId)
+
+	// Reset the container ID so that we're idempotent
+	s.containerId = ""
 }

builder/docker/step_run_test.go

@@ -0,0 +1,95 @@
+package docker
+
+import (
+	"errors"
+	"github.com/mitchellh/multistep"
+	"testing"
+)
+
+func testStepRunState(t *testing.T) multistep.StateBag {
+	state := testState(t)
+	state.Put("temp_dir", "/foo")
+	return state
+}
+
+func TestStepRun_impl(t *testing.T) {
+	var _ multistep.Step = new(StepRun)
+}
+
+func TestStepRun(t *testing.T) {
+	state := testStepRunState(t)
+	step := new(StepRun)
+	defer step.Cleanup(state)
+
+	config := state.Get("config").(*Config)
+	driver := state.Get("driver").(*MockDriver)
+	driver.StartID = "foo"
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionContinue {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// verify we did the right thing
+	if !driver.StartCalled {
+		t.Fatal("should've called")
+	}
+	if driver.StartConfig.Image != config.Image {
+		t.Fatalf("bad: %#v", driver.StartConfig.Image)
+	}
+
+	// verify the ID is saved
+	idRaw, ok := state.GetOk("container_id")
+	if !ok {
+		t.Fatal("should've saved ID")
+	}
+
+	id := idRaw.(string)
+	if id != "foo" {
+		t.Fatalf("bad: %#v", id)
+	}
+
+	// Verify we haven't called stop yet
+	if driver.StopCalled {
+		t.Fatal("should not have stopped")
+	}
+
+	// Cleanup
+	step.Cleanup(state)
+	if !driver.StopCalled {
+		t.Fatal("should've stopped")
+	}
+	if driver.StopID != id {
+		t.Fatalf("bad: %#v", driver.StopID)
+	}
+}
+
+func TestStepRun_error(t *testing.T) {
+	state := testStepRunState(t)
+	step := new(StepRun)
+	defer step.Cleanup(state)
+
+	driver := state.Get("driver").(*MockDriver)
+	driver.StartError = errors.New("foo")
+
+	// run the step
+	if action := step.Run(state); action != multistep.ActionHalt {
+		t.Fatalf("bad action: %#v", action)
+	}
+
+	// verify the ID is not saved
+	if _, ok := state.GetOk("container_id"); ok {
+		t.Fatal("shouldn't save container ID")
+	}
+
+	// Verify we haven't called stop yet
+	if driver.StopCalled {
+		t.Fatal("should not have stopped")
+	}
+
+	// Cleanup
+	step.Cleanup(state)
+	if driver.StopCalled {
+		t.Fatal("should not have stopped")
+	}
+}