Add the support of launching spot instances in "amazon-ebs" AMI

builder/amazon/common/run_config.go

@@ -17,6 +17,7 @@ type RunConfig struct {
 	InstanceType             string            `mapstructure:"instance_type"`
 	RunTags                  map[string]string `mapstructure:"run_tags"`
 	SourceAmi                string            `mapstructure:"source_ami"`
+	SpotPrice                string            `mapstructure:"spot_price"`
 	RawSSHTimeout            string            `mapstructure:"ssh_timeout"`
 	SSHUsername              string            `mapstructure:"ssh_username"`
 	SSHPrivateKeyFile        string            `mapstructure:"ssh_private_key_file"`

builder/amazon/common/state.go

@@ -81,6 +81,32 @@ func InstanceStateRefreshFunc(conn *ec2.EC2, i *ec2.Instance) StateRefreshFunc {
 	}
 }
 
+// SpotRequestStateRefreshFunc returns a StateRefreshFunc that is used to watch
+// a spot request for state changes.
+func SpotRequestStateRefreshFunc(conn *ec2.EC2, spotRequestId string) StateRefreshFunc {
+	return func() (interface{}, string, error) {
+		resp, err := conn.DescribeSpotRequests([]string{spotRequestId}, ec2.NewFilter())
+		if err != nil {
+			if ec2err, ok := err.(*ec2.Error); ok && ec2err.Code == "InvalidSpotInstanceRequestID.NotFound" {
+				// Set this to nil as if we didn't find anything.
+				resp = nil
+			} else {
+				log.Printf("Error on SpotRequestStateRefresh: %s", err)
+				return nil, "", err
+			}
+		}
+
+		if resp == nil || len(resp.SpotRequestResults) == 0 {
+			// Sometimes AWS has consistency issues and doesn't see the
+			// SpotRequest. Return an empty state.
+			return nil, "", nil
+		}
+
+		i := resp.SpotRequestResults[0]
+		return i, i.State, nil
+	}
+}
+
 // WaitForState watches an object and waits for it to achieve a certain
 // state.
 func WaitForState(conf *StateChangeConf) (i interface{}, err error) {

builder/amazon/common/step_run_source_instance.go

@@ -10,6 +10,7 @@ import (
 
 type StepRunSourceInstance struct {
 	AssociatePublicIpAddress bool
+	SpotPrice                string
 	AvailabilityZone         string
 	BlockDevices             BlockDevices
 	Debug                    bool
@@ -47,21 +48,6 @@ func (s *StepRunSourceInstance) Run(state multistep.StateBag) multistep.StepActi
 		securityGroups[n] = ec2.SecurityGroup{Id: securityGroupId}
 	}
 
-	runOpts := &ec2.RunInstances{
-		KeyName:                  keyName,
-		ImageId:                  s.SourceAMI,
-		InstanceType:             s.InstanceType,
-		UserData:                 []byte(userData),
-		MinCount:                 0,
-		MaxCount:                 0,
-		SecurityGroups:           securityGroups,
-		IamInstanceProfile:       s.IamInstanceProfile,
-		SubnetId:                 s.SubnetId,
-		AssociatePublicIpAddress: s.AssociatePublicIpAddress,
-		BlockDevices:             s.BlockDevices.BuildLaunchDevices(),
-		AvailZone:                s.AvailabilityZone,
-	}
-
 	ui.Say("Launching a source AWS instance...")
 	imageResp, err := ec2conn.Images([]string{s.SourceAMI}, ec2.NewFilter())
 	if err != nil {
@@ -82,15 +68,85 @@ func (s *StepRunSourceInstance) Run(state multistep.StateBag) multistep.StepActi
 		return multistep.ActionHalt
 	}
 
-	runResp, err := ec2conn.RunInstances(runOpts)
+	var instanceId []string
+	if s.SpotPrice == "" {
+		runOpts := &ec2.RunInstances{
+			KeyName:                  keyName,
+			ImageId:                  s.SourceAMI,
+			InstanceType:             s.InstanceType,
+			UserData:                 []byte(userData),
+			MinCount:                 0,
+			MaxCount:                 0,
+			SecurityGroups:           securityGroups,
+			IamInstanceProfile:       s.IamInstanceProfile,
+			SubnetId:                 s.SubnetId,
+			AssociatePublicIpAddress: s.AssociatePublicIpAddress,
+			BlockDevices:             s.BlockDevices.BuildLaunchDevices(),
+			AvailZone:                s.AvailabilityZone,
+		}
+		runResp, err := ec2conn.RunInstances(runOpts)
+		if err != nil {
+			err := fmt.Errorf("Error launching source instance: %s", err)
+			state.Put("error", err)
+			ui.Error(err.Error())
+			return multistep.ActionHalt
+		}
+		instanceId = []string{runResp.Instances[0].InstanceId}
+
+	} else {
+		runOpts := &ec2.RequestSpotInstances{
+			SpotPrice:                s.SpotPrice,
+			KeyName:                  keyName,
+			ImageId:                  s.SourceAMI,
+			InstanceType:             s.InstanceType,
+			UserData:                 []byte(userData),
+			SecurityGroups:           securityGroups,
+			IamInstanceProfile:       s.IamInstanceProfile,
+			SubnetId:                 s.SubnetId,
+			AssociatePublicIpAddress: s.AssociatePublicIpAddress,
+			BlockDevices:             s.BlockDevices.BuildLaunchDevices(),
+			AvailZone:                s.AvailabilityZone,
+		}
+		runSpotResp, err := ec2conn.RequestSpotInstances(runOpts)
+		if err != nil {
+			err := fmt.Errorf("Error launching source spot instance: %s", err)
+			state.Put("error", err)
+			ui.Error(err.Error())
+			return multistep.ActionHalt
+		}
+		spotRequestId := runSpotResp.SpotRequestResults[0].SpotRequestId
+		ui.Say(fmt.Sprintf("Waiting for spot request (%s) to become ready...", spotRequestId))
+		stateChange := StateChangeConf{
+			Pending:   []string{"open"},
+			Target:    "active",
+			Refresh:   SpotRequestStateRefreshFunc(ec2conn, spotRequestId),
+			StepState: state,
+		}
+		_, err = WaitForState(&stateChange)
+		if err != nil {
+			err := fmt.Errorf("Error waiting for spot request (%s) to become ready: %s", spotRequestId, err)
+			state.Put("error", err)
+			ui.Error(err.Error())
+			return multistep.ActionHalt
+		}
+		spotResp, err := ec2conn.DescribeSpotRequests([]string{spotRequestId}, nil)
+		if err != nil {
+			err := fmt.Errorf("Error finding spot request (%s): %s", spotRequestId, err)
+			state.Put("error", err)
+			ui.Error(err.Error())
+			return multistep.ActionHalt
+		}
+		instanceId = []string{spotResp.SpotRequestResults[0].InstanceId}
+	}
+
+	instanceResp, err := ec2conn.Instances(instanceId, nil)
 	if err != nil {
-		err := fmt.Errorf("Error launching source instance: %s", err)
+		err := fmt.Errorf("Error finding source instance (%s): %s", instanceId, err)
 		state.Put("error", err)
 		ui.Error(err.Error())
 		return multistep.ActionHalt
 	}
-
-	s.instance = &runResp.Instances[0]
+	s.instance = &instanceResp.Reservations[0].Instances[0]
 	ui.Message(fmt.Sprintf("Instance ID: %s", s.instance.InstanceId))
 
 	ec2Tags := make([]ec2.Tag, 1, len(s.Tags)+1)

builder/amazon/ebs/builder.go

@@ -96,6 +96,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 		&awscommon.StepRunSourceInstance{
 			Debug:                    b.config.PackerDebug,
 			ExpectedRootDevice:       "ebs",
+			SpotPrice:                b.config.SpotPrice,
 			InstanceType:             b.config.InstanceType,
 			UserData:                 b.config.UserData,
 			UserDataFile:             b.config.UserDataFile,
@@ -113,7 +114,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			SSHWaitTimeout: b.config.SSHTimeout(),
 		},
 		&common.StepProvision{},
-		&stepStopInstance{},
+		&stepStopInstance{SpotPrice: b.config.SpotPrice},
 		&stepCreateAMI{},
 		&awscommon.StepAMIRegionCopy{
 			Regions: b.config.AMIRegions,

builder/amazon/ebs/step_stop_instance.go

@@ -8,13 +8,21 @@ import (
 	"github.com/mitchellh/packer/packer"
 )
 
-type stepStopInstance struct{}
+type stepStopInstance struct{
+    SpotPrice string
+}
 
 func (s *stepStopInstance) Run(state multistep.StateBag) multistep.StepAction {
 	ec2conn := state.Get("ec2").(*ec2.EC2)
 	instance := state.Get("instance").(*ec2.Instance)
 	ui := state.Get("ui").(packer.Ui)
 
+        // Skip when it is a spot instance
+        if s.SpotPrice != "" {
+		ui.Say(fmt.Sprintf("This is a spot instance, no need to stop for the AMI"))
+	        return multistep.ActionContinue
+        }
+
 	// Stop the instance so we can create an AMI from it
 	ui.Say("Stopping the source instance...")
 	_, err := ec2conn.StopInstances(instance.InstanceId)