builder/docker: support custom communicators

builder/docker/builder.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/common"
+	"github.com/mitchellh/packer/helper/communicator"
 	"github.com/mitchellh/packer/packer"
 )
 
@@ -42,7 +43,15 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		&StepTempDir{},
 		&StepPull{},
 		&StepRun{},
-		&StepProvision{},
+		&communicator.StepConnect{
+			Config:    &b.config.Comm,
+			Host:      commHost,
+			SSHConfig: sshConfig(&b.config.Comm),
+			CustomConnect: map[string]multistep.Step{
+				"docker": &StepConnectDocker{},
+			},
+		},
+		&common.StepProvision{},
 	}
 
 	if b.config.Commit {

builder/docker/comm.go

@@ -0,0 +1,52 @@
+package docker
+
+import (
+	"fmt"
+	"io/ioutil"
+
+	"github.com/mitchellh/multistep"
+	"github.com/mitchellh/packer/communicator/ssh"
+	"github.com/mitchellh/packer/helper/communicator"
+	gossh "golang.org/x/crypto/ssh"
+)
+
+func commHost(state multistep.StateBag) (string, error) {
+	containerId := state.Get("container_id").(string)
+	driver := state.Get("driver").(Driver)
+	return driver.IPAddress(containerId)
+}
+
+func sshConfig(comm *communicator.Config) func(state multistep.StateBag) (*gossh.ClientConfig, error) {
+	return func(state multistep.StateBag) (*gossh.ClientConfig, error) {
+		if comm.SSHPrivateKey != "" {
+			// key based auth
+			bytes, err := ioutil.ReadFile(comm.SSHPrivateKey)
+			if err != nil {
+				return nil, fmt.Errorf("Error setting up SSH config: %s", err)
+			}
+			privateKey := string(bytes)
+
+			signer, err := gossh.ParsePrivateKey([]byte(privateKey))
+			if err != nil {
+				return nil, fmt.Errorf("Error setting up SSH config: %s", err)
+			}
+
+			return &gossh.ClientConfig{
+				User: comm.SSHUsername,
+				Auth: []gossh.AuthMethod{
+					gossh.PublicKeys(signer),
+				},
+			}, nil
+		} else {
+			// password based auth
+			return &gossh.ClientConfig{
+				User: comm.SSHUsername,
+				Auth: []gossh.AuthMethod{
+					gossh.Password(comm.SSHPassword),
+					gossh.KeyboardInteractive(
+						ssh.PasswordKeyboardInteractive(comm.SSHPassword)),
+				},
+			}, nil
+		}
+	}
+}

builder/docker/config.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/mitchellh/mapstructure"
 	"github.com/mitchellh/packer/common"
+	"github.com/mitchellh/packer/helper/communicator"
 	"github.com/mitchellh/packer/helper/config"
 	"github.com/mitchellh/packer/packer"
 	"github.com/mitchellh/packer/template/interpolate"
@@ -13,6 +14,7 @@ import (
 
 type Config struct {
 	common.PackerConfig `mapstructure:",squash"`
+	Comm                communicator.Config `mapstructure:",squash"`
 
 	Commit     bool
 	ExportPath string `mapstructure:"export_path"`
@@ -69,7 +71,15 @@ func NewConfig(raws ...interface{}) (*Config, []string, error) {
 		c.Pull = true
 	}
 
+	// Default to the normal Docker type
+	if c.Comm.Type == "" {
+		c.Comm.Type = "docker"
+	}
+
 	var errs *packer.MultiError
+	if es := c.Comm.Prepare(&c.ctx); len(es) > 0 {
+		errs = packer.MultiErrorAppend(errs, es...)
+	}
 	if c.Image == "" {
 		errs = packer.MultiErrorAppend(errs,
 			fmt.Errorf("image must be specified"))

builder/docker/driver.go

@@ -22,6 +22,10 @@ type Driver interface {
 	// Import imports a container from a tar file
 	Import(path, repo string) (string, error)
 
+	// IPAddress returns the address of the container that can be used
+	// for external access.
+	IPAddress(id string) (string, error)
+
 	// Login. This will lock the driver from performing another Login
 	// until Logout is called. Therefore, any users MUST call Logout.
 	Login(repo, email, username, password string) error

builder/docker/driver_docker.go

@@ -116,6 +116,23 @@ func (d *DockerDriver) Import(path string, repo string) (string, error) {
 	return strings.TrimSpace(stdout.String()), nil
 }
 
+func (d *DockerDriver) IPAddress(id string) (string, error) {
+	var stderr, stdout bytes.Buffer
+	cmd := exec.Command(
+		"docker",
+		"inspect",
+		"--format",
+		"{{ .NetworkSettings.IPAddress }}",
+		id)
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+	if err := cmd.Run(); err != nil {
+		return "", fmt.Errorf("Error: %s\n\nStderr: %s", err, stderr.String())
+	}
+
+	return strings.TrimSpace(stdout.String()), nil
+}
+
 func (d *DockerDriver) Login(repo, email, user, pass string) error {
 	d.l.Lock()
 

builder/docker/driver_mock.go

@@ -23,6 +23,11 @@ type MockDriver struct {
 	ImportId     string
 	ImportErr    error
 
+	IPAddressCalled bool
+	IPAddressID     string
+	IPAddressResult string
+	IPAddressErr    error
+
 	LoginCalled   bool
 	LoginEmail    string
 	LoginUsername string
@@ -104,6 +109,12 @@ func (d *MockDriver) Import(path, repo string) (string, error) {
 	return d.ImportId, d.ImportErr
 }
 
+func (d *MockDriver) IPAddress(id string) (string, error) {
+	d.IPAddressCalled = true
+	d.IPAddressID = id
+	return d.IPAddressResult, d.IPAddressErr
+}
+
 func (d *MockDriver) Login(r, e, u, p string) error {
 	d.LoginCalled = true
 	d.LoginRepo = r

builder/docker/step_connect_docker.go

@@ -2,12 +2,11 @@ package docker
 
 import (
 	"github.com/mitchellh/multistep"
-	"github.com/mitchellh/packer/common"
 )
 
-type StepProvision struct{}
+type StepConnectDocker struct{}
 
-func (s *StepProvision) Run(state multistep.StateBag) multistep.StepAction {
+func (s *StepConnectDocker) Run(state multistep.StateBag) multistep.StepAction {
 	containerId := state.Get("container_id").(string)
 	driver := state.Get("driver").(Driver)
 	tempDir := state.Get("temp_dir").(string)
@@ -28,8 +27,8 @@ func (s *StepProvision) Run(state multistep.StateBag) multistep.StepAction {
 		Version:      version,
 	}
 
-	prov := common.StepProvision{Comm: comm}
+	state.Put("communicator", comm)
-	return prov.Run(state)
+	return multistep.ActionContinue
 }
 
-func (s *StepProvision) Cleanup(state multistep.StateBag) {}
+func (s *StepConnectDocker) Cleanup(state multistep.StateBag) {}

helper/communicator/step_connect.go

@@ -32,6 +32,11 @@ type StepConnect struct {
 	// connecting via WinRM.
 	WinRMConfig func(multistep.StateBag) (*WinRMConfig, error)
 
+	// CustomConnect can be set to have custom connectors for specific
+	// types. These take highest precedence so you can also override
+	// existing types.
+	CustomConnect map[string]multistep.Step
+
 	substep multistep.Step
 }
 
@@ -50,6 +55,9 @@ func (s *StepConnect) Run(state multistep.StateBag) multistep.StepAction {
 			WinRMConfig: s.WinRMConfig,
 		},
 	}
+	for k, v := range s.CustomConnect {
+		typeMap[k] = v
+	}
 
 	step, ok := typeMap[s.Config.Type]
 	if !ok {