builder/amazon/chroot: boilerplate

builder/amazon/chroot/builder.go

+// The chroot package is able to create an Amazon AMI without requiring
+// the launch of a new instance for every build. It does this by attaching
+// and mounting the root volume of another AMI and chrooting into that
+// directory. It then creates an AMI from that attached drive.
+package chroot
+
+import (
+	"github.com/mitchellh/goamz/ec2"
+	"github.com/mitchellh/multistep"
+	awscommon "github.com/mitchellh/packer/builder/amazon/common"
+	"github.com/mitchellh/packer/builder/common"
+	"github.com/mitchellh/packer/packer"
+	"log"
+)
+
+// The unique ID for this builder
+const BuilderId = "mitchellh.amazon.chroot"
+
+// Config is the configuration that is chained through the steps and
+// settable from the template.
+type Config struct {
+	common.PackerConfig    `mapstructure:",squash"`
+	awscommon.AccessConfig `mapstructure:",squash"`
+}
+
+type Builder struct {
+	config Config
+	runner multistep.Runner
+}
+
+func (b *Builder) Prepare(raws ...interface{}) error {
+	md, err := common.DecodeConfig(&b.config, raws...)
+	if err != nil {
+		return err
+	}
+
+	// Defaults
+
+	// Accumulate any errors
+	errs := common.CheckUnusedConfig(md)
+	errs = packer.MultiErrorAppend(errs, b.config.AccessConfig.Prepare()...)
+
+	if errs != nil && len(errs.Errors) > 0 {
+		return errs
+	}
+
+	log.Printf("Config: %+v", b.config)
+	return nil
+}
+
+func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) {
+	region, err := b.config.Region()
+	if err != nil {
+		return nil, err
+	}
+
+	auth, err := b.config.AccessConfig.Auth()
+	if err != nil {
+		return nil, err
+	}
+
+	ec2conn := ec2.New(auth, region)
+
+	// Setup the state bag and initial state for the steps
+	state := make(map[string]interface{})
+	state["config"] = &b.config
+	state["ec2"] = ec2conn
+	state["hook"] = hook
+	state["ui"] = ui
+
+	// Build the steps
+	steps := []multistep.Step{}
+
+	// Run!
+	if b.config.PackerDebug {
+		b.runner = &multistep.DebugRunner{
+			Steps:   steps,
+			PauseFn: common.MultistepDebugFn(ui),
+		}
+	} else {
+		b.runner = &multistep.BasicRunner{Steps: steps}
+	}
+
+	b.runner.Run(state)
+
+	// If there was an error, return that
+	if rawErr, ok := state["error"]; ok {
+		return nil, rawErr.(error)
+	}
+
+	// If there are no AMIs, then just return
+	if _, ok := state["amis"]; !ok {
+		return nil, nil
+	}
+
+	// Build the artifact and return it
+	artifact := &awscommon.Artifact{
+		Amis:           state["amis"].(map[string]string),
+		BuilderIdValue: BuilderId,
+		Conn:           ec2conn,
+	}
+
+	return artifact, nil
+}
+
+func (b *Builder) Cancel() {
+	if b.runner != nil {
+		log.Println("Cancelling the step runner...")
+		b.runner.Cancel()
+	}
+}

builder/amazon/chroot/builder_test.go

+package chroot
+
+import (
+	"github.com/mitchellh/packer/packer"
+	"testing"
+)
+
+func testConfig() map[string]interface{} {
+	return map[string]interface{}{}
+}
+
+func TestBuilder_ImplementsBuilder(t *testing.T) {
+	var raw interface{}
+	raw = &Builder{}
+	if _, ok := raw.(packer.Builder); !ok {
+		t.Fatalf("Builder should be a builder")
+	}
+}

builder/amazon/common/access_config.go

 package common
 
 import (
+	"fmt"
 	"github.com/mitchellh/goamz/aws"
+	"strings"
+	"unicode"
 )
 
 // AccessConfig is for common configuration related to AWS access
 type AccessConfig struct {
 	AccessKey string `mapstructure:"access_key"`
 	SecretKey string `mapstructure:"secret_key"`
+	RawRegion string `mapstructure:"region"`
 }
 
 // Auth returns a valid aws.Auth object for access to AWS services, or
@@ -16,6 +20,28 @@ func (c *AccessConfig) Auth() (aws.Auth, error) {
 	return aws.GetAuth(c.AccessKey, c.SecretKey)
 }
 
+// Region returns the aws.Region object for access to AWS services, requesting
+// the region from the instance metadata if possible.
+func (c *AccessConfig) Region() (aws.Region, error) {
+	if c.RawRegion != "" {
+		return aws.Regions[c.RawRegion], nil
+	}
+
+	md, err := aws.GetMetaData("placement/availability-zone")
+	if err != nil {
+		return aws.Region{}, err
+	}
+
+	region := strings.TrimRightFunc(string(md), unicode.IsLetter)
+	return aws.Regions[region], nil
+}
+
 func (c *AccessConfig) Prepare() []error {
+	if c.RawRegion != "" {
+		if _, ok := aws.Regions[c.RawRegion]; !ok {
+			return []error{fmt.Errorf("Unknown region: %s", c.RawRegion)}
+		}
+	}
+
 	return nil
 }

builder/amazon/common/access_config_test.go

+package common
+
+import (
+	"testing"
+)
+
+func testAccessConfig() *AccessConfig {
+	return &AccessConfig{}
+}
+
+func TestAccessConfigPrepare_Region(t *testing.T) {
+	c := testAccessConfig()
+	c.RawRegion = ""
+	if err := c.Prepare(); err != nil {
+		t.Fatalf("shouldn't have err: %s", err)
+	}
+
+	c.RawRegion = "us-east-12"
+	if err := c.Prepare(); err == nil {
+		t.Fatal("should have error")
+	}
+
+	c.RawRegion = "us-east-1"
+	if err := c.Prepare(); err != nil {
+		t.Fatalf("shouldn't have err: %s", err)
+	}
+}

builder/amazon/common/run_config.go

@@ -3,14 +3,12 @@ package common
 import (
 	"errors"
 	"fmt"
-	"github.com/mitchellh/goamz/aws"
 	"time"
 )
 
 // RunConfig contains configuration for running an instance from a source
 // AMI and details on how to access that launched image.
 type RunConfig struct {
-	Region          string
 	SourceAmi       string `mapstructure:"source_ami"`
 	InstanceType    string `mapstructure:"instance_type"`
 	RawSSHTimeout   string `mapstructure:"ssh_timeout"`
@@ -45,12 +43,6 @@ func (c *RunConfig) Prepare() []error {
 		errs = append(errs, errors.New("An instance_type must be specified"))
 	}
 
-	if c.Region == "" {
-		errs = append(errs, errors.New("A region must be specified"))
-	} else if _, ok := aws.Regions[c.Region]; !ok {
-		errs = append(errs, fmt.Errorf("Unknown region: %s", c.Region))
-	}
-
 	if c.SSHUsername == "" {
 		errs = append(errs, errors.New("An ssh_username must be specified"))
 	}

builder/amazon/common/run_config_test.go

@@ -16,7 +16,6 @@ func init() {
 
 func testConfig() *RunConfig {
 	return &RunConfig{
-		Region:       "us-east-1",
 		SourceAmi:    "abcd",
 		InstanceType: "m1.small",
 		SSHUsername:  "root",
@@ -39,24 +38,6 @@ func TestRunConfigPrepare_InstanceType(t *testing.T) {
 	}
 }
 
-func TestRunConfigPrepare_Region(t *testing.T) {
-	c := testConfig()
-	c.Region = ""
-	if err := c.Prepare(); len(err) != 1 {
-		t.Fatalf("err: %s", err)
-	}
-
-	c.Region = "us-east-12"
-	if err := c.Prepare(); len(err) != 1 {
-		t.Fatalf("err: %s", err)
-	}
-
-	c.Region = "us-east-1"
-	if err := c.Prepare(); len(err) != 0 {
-		t.Fatalf("err: %s", err)
-	}
-}
-
 func TestRunConfigPrepare_SourceAmi(t *testing.T) {
 	c := testConfig()
 	c.SourceAmi = ""

builder/amazon/ebs/builder.go

@@ -8,7 +8,6 @@ package ebs
 import (
 	"errors"
 	"fmt"
-	"github.com/mitchellh/goamz/aws"
 	"github.com/mitchellh/goamz/ec2"
 	"github.com/mitchellh/multistep"
 	awscommon "github.com/mitchellh/packer/builder/amazon/common"
@@ -67,9 +66,9 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 }
 
 func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) {
-	region, ok := aws.Regions[b.config.Region]
-	if !ok {
-		panic("region not found")
+	region, err := b.config.Region()
+	if err != nil {
+		return nil, err
 	}
 
 	auth, err := b.config.AccessConfig.Auth()

builder/amazon/ebs/step_create_ami.go

@@ -52,7 +52,7 @@ func (s *stepCreateAMI) Run(state map[string]interface{}) multistep.StepAction {
 	// Set the AMI ID in the state
 	ui.Say(fmt.Sprintf("AMI: %s", createResp.ImageId))
 	amis := make(map[string]string)
-	amis[config.Region] = createResp.ImageId
+	amis[ec2conn.Region.Name] = createResp.ImageId
 	state["amis"] = amis
 
 	// Wait for the image to become ready

builder/amazon/instance/builder.go

@@ -5,7 +5,6 @@ package instance
 import (
 	"errors"
 	"fmt"
-	"github.com/mitchellh/goamz/aws"
 	"github.com/mitchellh/goamz/ec2"
 	"github.com/mitchellh/multistep"
 	awscommon "github.com/mitchellh/packer/builder/amazon/common"
@@ -134,9 +133,9 @@ func (b *Builder) Prepare(raws ...interface{}) error {
 }
 
 func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packer.Artifact, error) {
-	region, ok := aws.Regions[b.config.Region]
-	if !ok {
-		panic("region not found")
+	region, err := b.config.Region()
+	if err != nil {
+		return nil, err
 	}
 
 	auth, err := b.config.AccessConfig.Auth()

builder/amazon/instance/step_register_ami.go

@@ -50,7 +50,7 @@ func (s *StepRegisterAMI) Run(state map[string]interface{}) multistep.StepAction
 	// Set the AMI ID in the state
 	ui.Say(fmt.Sprintf("AMI: %s", registerResp.ImageId))
 	amis := make(map[string]string)
-	amis[config.Region] = registerResp.ImageId
+	amis[ec2conn.Region.Name] = registerResp.ImageId
 	state["amis"] = amis
 
 	// Wait for the image to become ready

plugin/builder-amazon-ebs-chroot/main.go

+package main
+
+import (
+	"github.com/mitchellh/packer/builder/amazon/chroot"
+	"github.com/mitchellh/packer/packer/plugin"
+)
+
+func main() {
+	plugin.ServeBuilder(new(chroot.Builder))
+}