github.com/kaixiang/packer@v0.5.2-0.20140114230416-1f5786b0d7f1/builder/amazon/chroot/step_attach_volume.go (about)

     1  package chroot
     2  
     3  import (
     4  	"errors"
     5  	"fmt"
     6  	"github.com/mitchellh/goamz/ec2"
     7  	"github.com/mitchellh/multistep"
     8  	awscommon "github.com/mitchellh/packer/builder/amazon/common"
     9  	"github.com/mitchellh/packer/packer"
    10  	"strings"
    11  )
    12  
    13  // StepAttachVolume attaches the previously created volume to an
    14  // available device location.
    15  //
    16  // Produces:
    17  //   device string - The location where the volume was attached.
    18  //   attach_cleanup CleanupFunc
    19  type StepAttachVolume struct {
    20  	attached bool
    21  	volumeId string
    22  }
    23  
    24  func (s *StepAttachVolume) Run(state multistep.StateBag) multistep.StepAction {
    25  	ec2conn := state.Get("ec2").(*ec2.EC2)
    26  	device := state.Get("device").(string)
    27  	instance := state.Get("instance").(*ec2.Instance)
    28  	ui := state.Get("ui").(packer.Ui)
    29  	volumeId := state.Get("volume_id").(string)
    30  
    31  	// For the API call, it expects "sd" prefixed devices.
    32  	attachVolume := strings.Replace(device, "/xvd", "/sd", 1)
    33  
    34  	ui.Say(fmt.Sprintf("Attaching the root volume to %s", attachVolume))
    35  	_, err := ec2conn.AttachVolume(volumeId, instance.InstanceId, attachVolume)
    36  	if err != nil {
    37  		err := fmt.Errorf("Error attaching volume: %s", err)
    38  		state.Put("error", err)
    39  		ui.Error(err.Error())
    40  		return multistep.ActionHalt
    41  	}
    42  
    43  	// Mark that we attached it so we can detach it later
    44  	s.attached = true
    45  	s.volumeId = volumeId
    46  
    47  	// Wait for the volume to become attached
    48  	stateChange := awscommon.StateChangeConf{
    49  		Pending:   []string{"attaching"},
    50  		StepState: state,
    51  		Target:    "attached",
    52  		Refresh: func() (interface{}, string, error) {
    53  			resp, err := ec2conn.Volumes([]string{volumeId}, ec2.NewFilter())
    54  			if err != nil {
    55  				return nil, "", err
    56  			}
    57  
    58  			if len(resp.Volumes[0].Attachments) == 0 {
    59  				return nil, "", errors.New("No attachments on volume.")
    60  			}
    61  
    62  			a := resp.Volumes[0].Attachments[0]
    63  			return a, a.Status, nil
    64  		},
    65  	}
    66  
    67  	_, err = awscommon.WaitForState(&stateChange)
    68  	if err != nil {
    69  		err := fmt.Errorf("Error waiting for volume: %s", err)
    70  		state.Put("error", err)
    71  		ui.Error(err.Error())
    72  		return multistep.ActionHalt
    73  	}
    74  
    75  	state.Put("attach_cleanup", s)
    76  	return multistep.ActionContinue
    77  }
    78  
    79  func (s *StepAttachVolume) Cleanup(state multistep.StateBag) {
    80  	ui := state.Get("ui").(packer.Ui)
    81  	if err := s.CleanupFunc(state); err != nil {
    82  		ui.Error(err.Error())
    83  	}
    84  }
    85  
    86  func (s *StepAttachVolume) CleanupFunc(state multistep.StateBag) error {
    87  	if !s.attached {
    88  		return nil
    89  	}
    90  
    91  	ec2conn := state.Get("ec2").(*ec2.EC2)
    92  	ui := state.Get("ui").(packer.Ui)
    93  
    94  	ui.Say("Detaching EBS volume...")
    95  	_, err := ec2conn.DetachVolume(s.volumeId)
    96  	if err != nil {
    97  		return fmt.Errorf("Error detaching EBS volume: %s", err)
    98  	}
    99  
   100  	s.attached = false
   101  
   102  	// Wait for the volume to detach
   103  	stateChange := awscommon.StateChangeConf{
   104  		Pending:   []string{"attaching", "attached", "detaching"},
   105  		StepState: state,
   106  		Target:    "detached",
   107  		Refresh: func() (interface{}, string, error) {
   108  			resp, err := ec2conn.Volumes([]string{s.volumeId}, ec2.NewFilter())
   109  			if err != nil {
   110  				return nil, "", err
   111  			}
   112  
   113  			v := resp.Volumes[0]
   114  			if len(v.Attachments) > 0 {
   115  				return v, v.Attachments[0].Status, nil
   116  			} else {
   117  				return v, "detached", nil
   118  			}
   119  		},
   120  	}
   121  
   122  	_, err = awscommon.WaitForState(&stateChange)
   123  	if err != nil {
   124  		return fmt.Errorf("Error waiting for volume: %s", err)
   125  	}
   126  
   127  	return nil
   128  }