package chroot import ( "errors" "fmt" "strings" "time" "github.com/aws/aws-sdk-go/service/ec2" "github.com/mitchellh/multistep" awscommon "github.com/mitchellh/packer/builder/amazon/common" "github.com/mitchellh/packer/packer" ) // StepAttachVolume attaches the previously created volume to an // available device location. // // Produces: // device string - The location where the volume was attached. // attach_cleanup CleanupFunc type StepAttachVolume struct { attached bool volumeId string } func (s *StepAttachVolume) Run(state multistep.StateBag) multistep.StepAction { ec2conn := state.Get("ec2").(*ec2.EC2) device := state.Get("device").(string) instance := state.Get("instance").(*ec2.Instance) ui := state.Get("ui").(packer.Ui) volumeId := state.Get("volume_id").(string) // For the API call, it expects "sd" prefixed devices. attachVolume := strings.Replace(device, "/xvd", "/sd", 1) ui.Say(fmt.Sprintf("Attaching the root volume to %s", attachVolume)) _, err := ec2conn.AttachVolume(&ec2.AttachVolumeInput{ InstanceId: instance.InstanceId, VolumeId: &volumeId, Device: &attachVolume, }) if err != nil { err := fmt.Errorf("Error attaching volume: %s", err) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } // Mark that we attached it so we can detach it later s.attached = true s.volumeId = volumeId // Wait for the volume to become attached stateChange := awscommon.StateChangeConf{ Pending: []string{"attaching"}, StepState: state, Target: "attached", Refresh: func() (interface{}, string, error) { attempts := 0 for attempts < 30 { resp, err := ec2conn.DescribeVolumes(&ec2.DescribeVolumesInput{VolumeIds: []*string{&volumeId}}) if err != nil { return nil, "", err } if len(resp.Volumes[0].Attachments) > 0 { a := resp.Volumes[0].Attachments[0] return a, *a.State, nil } // When Attachment on volume is not present sleep for 2s and retry attempts += 1 ui.Say(fmt.Sprintf( "Volume %s show no attachments. Attempt %d/30. Sleeping for 2s and will retry.", volumeId, attempts)) time.Sleep(2 * time.Second) } // Attachment on volume is not present after all attempts return nil, "", errors.New("No attachments on volume.") }, } _, err = awscommon.WaitForState(&stateChange) if err != nil { err := fmt.Errorf("Error waiting for volume: %s", err) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } state.Put("attach_cleanup", s) return multistep.ActionContinue } func (s *StepAttachVolume) Cleanup(state multistep.StateBag) { ui := state.Get("ui").(packer.Ui) if err := s.CleanupFunc(state); err != nil { ui.Error(err.Error()) } } func (s *StepAttachVolume) CleanupFunc(state multistep.StateBag) error { if !s.attached { return nil } ec2conn := state.Get("ec2").(*ec2.EC2) ui := state.Get("ui").(packer.Ui) ui.Say("Detaching EBS volume...") _, err := ec2conn.DetachVolume(&ec2.DetachVolumeInput{VolumeId: &s.volumeId}) if err != nil { return fmt.Errorf("Error detaching EBS volume: %s", err) } s.attached = false // Wait for the volume to detach stateChange := awscommon.StateChangeConf{ Pending: []string{"attaching", "attached", "detaching"}, StepState: state, Target: "detached", Refresh: func() (interface{}, string, error) { resp, err := ec2conn.DescribeVolumes(&ec2.DescribeVolumesInput{VolumeIds: []*string{&s.volumeId}}) if err != nil { return nil, "", err } v := resp.Volumes[0] if len(v.Attachments) > 0 { return v, *v.Attachments[0].State, nil } else { return v, "detached", nil } }, } _, err = awscommon.WaitForState(&stateChange) if err != nil { return fmt.Errorf("Error waiting for volume: %s", err) } return nil }