builder/amazonebs: extract multistep, use that

builder/amazonebs/builder.go

@@ -9,6 +9,7 @@ import (
 	"github.com/mitchellh/goamz/aws"
 	"github.com/mitchellh/goamz/ec2"
 	"github.com/mitchellh/mapstructure"
+	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
 	"log"
 )
@@ -87,7 +88,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook) packer.Artifact {
 	state["ui"] = ui
 
 	// Build the steps
-	steps := []Step{
+	steps := []multistep.Step{
 		&stepKeyPair{},
 		&stepRunSourceInstance{},
 		&stepConnectSSH{},
@@ -97,7 +98,8 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook) packer.Artifact {
 	}
 
 	// Run!
-	RunSteps(state, steps)
+	runner := &multistep.BasicRunner{Steps: steps}
+	runner.Run(state)
 
 	// Build the artifact and return it
 	return &artifact{state["amis"].(map[string]string)}

builder/amazonebs/step.go

-package amazonebs
-
-// A StepAction determines the next step to take regarding multi-step actions.
-type StepAction uint
-
-const (
-	StepContinue StepAction = iota
-	StepHalt
-)
-
-// Step is a single step that is part of a potentially large sequence
-// of other steps, responsible for performing some specific action.
-type Step interface {
-	// Run is called to perform the action. The parameter is a "state bag"
-	// of untyped things. Please be very careful about type-checking the
-	// items in this bag.
-	//
-	// The return value determines whether multi-step sequences continue
-	// or should halt.
-	Run(map[string]interface{}) StepAction
-
-	// Cleanup is called in reverse order of the steps that have run
-	// and allow steps to clean up after themselves.
-	//
-	// The parameter is the same "state bag" as Run.
-	Cleanup(map[string]interface{})
-}
-
-// RunSteps runs a sequence of steps.
-func RunSteps(state map[string]interface{}, steps []Step) {
-	for _, step := range steps {
-		action := step.Run(state)
-		defer step.Cleanup(state)
-
-		if action == StepHalt {
-			break
-		}
-	}
-}

builder/amazonebs/step_connect_ssh.go

@@ -4,6 +4,7 @@ import (
 	gossh "code.google.com/p/go.crypto/ssh"
 	"fmt"
 	"github.com/mitchellh/goamz/ec2"
+	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/communicator/ssh"
 	"github.com/mitchellh/packer/packer"
 	"log"
@@ -15,7 +16,7 @@ type stepConnectSSH struct {
 	conn net.Conn
 }
 
-func (s *stepConnectSSH) Run(state map[string]interface{}) StepAction {
+func (s *stepConnectSSH) Run(state map[string]interface{}) multistep.StepAction {
 	config := state["config"].(config)
 	instance := state["instance"].(*ec2.Instance)
 	privateKey := state["privateKey"].(string)
@@ -27,7 +28,7 @@ func (s *stepConnectSSH) Run(state map[string]interface{}) StepAction {
 	err := keyring.AddPEMKey(privateKey)
 	if err != nil {
 		ui.Say(fmt.Sprintf("Error setting up SSH config: %s", err))
-		return StepHalt
+		return multistep.ActionHalt
 	}
 
 	// Build the actual SSH client configuration
@@ -59,13 +60,13 @@ func (s *stepConnectSSH) Run(state map[string]interface{}) StepAction {
 
 	if err != nil {
 		ui.Error(fmt.Sprintf("Error connecting to SSH: %s", err))
-		return StepHalt
+		return multistep.ActionHalt
 	}
 
 	// Set the communicator on the state bag so it can be used later
 	state["communicator"] = comm
 
-	return StepContinue
+	return multistep.ActionContinue
 }
 
 func (s *stepConnectSSH) Cleanup(map[string]interface{}) {

builder/amazonebs/step_create_ami.go

@@ -3,12 +3,13 @@ package amazonebs
 import (
 	"fmt"
 	"github.com/mitchellh/goamz/ec2"
+	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
 )
 
 type stepCreateAMI struct{}
 
-func (s *stepCreateAMI) Run(state map[string]interface{}) StepAction {
+func (s *stepCreateAMI) Run(state map[string]interface{}) multistep.StepAction {
 	config := state["config"].(config)
 	ec2conn := state["ec2"].(*ec2.EC2)
 	instance := state["instance"].(*ec2.Instance)
@@ -24,7 +25,7 @@ func (s *stepCreateAMI) Run(state map[string]interface{}) StepAction {
 	createResp, err := ec2conn.CreateImage(createOpts)
 	if err != nil {
 		ui.Error(err.Error())
-		return StepHalt
+		return multistep.ActionHalt
 	}
 
 	// Set the AMI ID in the state
@@ -39,7 +40,7 @@ func (s *stepCreateAMI) Run(state map[string]interface{}) StepAction {
 		imageResp, err := ec2conn.Images([]string{createResp.ImageId}, ec2.NewFilter())
 		if err != nil {
 			ui.Error(err.Error())
-			return StepHalt
+			return multistep.ActionHalt
 		}
 
 		if imageResp.Images[0].State == "available" {
@@ -47,7 +48,7 @@ func (s *stepCreateAMI) Run(state map[string]interface{}) StepAction {
 		}
 	}
 
-	return StepContinue
+	return multistep.ActionContinue
 }
 
 func (s *stepCreateAMI) Cleanup(map[string]interface{}) {

builder/amazonebs/step_keypair.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"github.com/mitchellh/goamz/ec2"
+	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
 	"log"
 )
@@ -13,7 +14,7 @@ type stepKeyPair struct {
 	keyName string
 }
 
-func (s *stepKeyPair) Run(state map[string]interface{}) StepAction {
+func (s *stepKeyPair) Run(state map[string]interface{}) multistep.StepAction {
 	ec2conn := state["ec2"].(*ec2.EC2)
 	ui := state["ui"].(packer.Ui)
 
@@ -23,7 +24,7 @@ func (s *stepKeyPair) Run(state map[string]interface{}) StepAction {
 	keyResp, err := ec2conn.CreateKeyPair(keyName)
 	if err != nil {
 		ui.Error(err.Error())
-		return StepHalt
+		return multistep.ActionHalt
 	}
 
 	// Set the keyname so we know to delete it later
@@ -33,7 +34,7 @@ func (s *stepKeyPair) Run(state map[string]interface{}) StepAction {
 	state["keyPair"] = keyName
 	state["privateKey"] = keyResp.KeyMaterial
 
-	return StepContinue
+	return multistep.ActionContinue
 }
 
 func (s *stepKeyPair) Cleanup(state map[string]interface{}) {

builder/amazonebs/step_provision.go

 package amazonebs
 
 import (
+	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
 	"log"
 )
 
 type stepProvision struct{}
 
-func (*stepProvision) Run(state map[string]interface{}) StepAction {
+func (*stepProvision) Run(state map[string]interface{}) multistep.StepAction {
 	comm := state["communicator"].(packer.Communicator)
 	hook := state["hook"].(packer.Hook)
 	ui := state["ui"].(packer.Ui)
@@ -15,7 +16,7 @@ func (*stepProvision) Run(state map[string]interface{}) StepAction {
 	log.Println("Running the provision hook")
 	hook.Run(packer.HookProvision, ui, comm, nil)
 
-	return StepContinue
+	return multistep.ActionContinue
 }
 
 func (*stepProvision) Cleanup(map[string]interface{}) {}

builder/amazonebs/step_run_source_instance.go

@@ -2,6 +2,7 @@ package amazonebs
 
 import (
 	"github.com/mitchellh/goamz/ec2"
+	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
 	"log"
 )
@@ -10,7 +11,7 @@ type stepRunSourceInstance struct {
 	instance *ec2.Instance
 }
 
-func (s *stepRunSourceInstance) Run(state map[string]interface{}) StepAction {
+func (s *stepRunSourceInstance) Run(state map[string]interface{}) multistep.StepAction {
 	config := state["config"].(config)
 	ec2conn := state["ec2"].(*ec2.EC2)
 	keyName := state["keyPair"].(string)
@@ -28,7 +29,7 @@ func (s *stepRunSourceInstance) Run(state map[string]interface{}) StepAction {
 	runResp, err := ec2conn.RunInstances(runOpts)
 	if err != nil {
 		ui.Error(err.Error())
-		return StepHalt
+		return multistep.ActionHalt
 	}
 
 	s.instance = &runResp.Instances[0]
@@ -38,12 +39,12 @@ func (s *stepRunSourceInstance) Run(state map[string]interface{}) StepAction {
 	s.instance, err = waitForState(ec2conn, s.instance, "running")
 	if err != nil {
 		ui.Error(err.Error())
-		return StepHalt
+		return multistep.ActionHalt
 	}
 
 	state["instance"] = s.instance
 
-	return StepContinue
+	return multistep.ActionContinue
 }
 
 func (s *stepRunSourceInstance) Cleanup(state map[string]interface{}) {

builder/amazonebs/step_stop_instance.go

@@ -2,12 +2,13 @@ package amazonebs
 
 import (
 	"github.com/mitchellh/goamz/ec2"
+	"github.com/mitchellh/multistep"
 	"github.com/mitchellh/packer/packer"
 )
 
 type stepStopInstance struct{}
 
-func (s *stepStopInstance) Run(state map[string]interface{}) StepAction {
+func (s *stepStopInstance) Run(state map[string]interface{}) multistep.StepAction {
 	ec2conn := state["ec2"].(*ec2.EC2)
 	instance := state["instance"].(*ec2.Instance)
 	ui := state["ui"].(packer.Ui)
@@ -17,7 +18,7 @@ func (s *stepStopInstance) Run(state map[string]interface{}) StepAction {
 	_, err := ec2conn.StopInstances(instance.InstanceId)
 	if err != nil {
 		ui.Error(err.Error())
-		return StepHalt
+		return multistep.ActionHalt
 	}
 
 	// Wait for the instance to actual stop
@@ -27,10 +28,10 @@ func (s *stepStopInstance) Run(state map[string]interface{}) StepAction {
 	instance, err = waitForState(ec2conn, instance, "stopped")
 	if err != nil {
 		ui.Error(err.Error())
-		return StepHalt
+		return multistep.ActionHalt
 	}
 
-	return StepContinue
+	return multistep.ActionContinue
 }
 
 func (s *stepStopInstance) Cleanup(map[string]interface{}) {