Golang EC2.Images方法代碼示例

// AMIStateRefreshFunc returns a StateRefreshFunc that is used to watch
// an AMI for state changes.
func AMIStateRefreshFunc(conn *ec2.EC2, imageId string) StateRefreshFunc {
	return func() (interface{}, string, error) {
		resp, err := conn.Images([]string{imageId}, ec2.NewFilter())
		if err != nil {
			if ec2err, ok := err.(*ec2.Error); ok && ec2err.Code == "InvalidAMIID.NotFound" {
				// Set this to nil as if we didn't find anything.
				resp = nil
			} else if isTransientNetworkError(err) {
				// Transient network error, treat it as if we didn't find anything
				resp = nil
			} else {
				log.Printf("Error on AMIStateRefresh: %s", err)
				return nil, "", err
			}
		}

		if resp == nil || len(resp.Images) == 0 {
			// Sometimes AWS has consistency issues and doesn't see the
			// AMI. Return an empty state.
			return nil, "", nil
		}

		i := resp.Images[0]
		return i, i.State, nil
	}
}

// findSnapshots returns a map of snapshots associated with an AMI
func findSnapshots(amiid string, awsec2 *ec2.EC2) (map[string]string, error) {
	snaps := make(map[string]string)
	resp, err := awsec2.Images([]string{amiid}, nil)
	if err != nil {
		return snaps, fmt.Errorf("EC2 API DescribeImages failed: %s", err.Error())
	}
	for _, image := range resp.Images {
		for _, bd := range image.BlockDevices {
			if len(bd.SnapshotId) > 0 {
				snaps[bd.SnapshotId] = bd.DeviceName
			}
		}
	}
	return snaps, nil
}

// WaitForAMI waits for the given AMI ID to become ready.
func WaitForAMI(c *ec2.EC2, imageId string) error {
	for {
		imageResp, err := c.Images([]string{imageId}, ec2.NewFilter())
		if err != nil {
			return err
		}

		if imageResp.Images[0].State == "available" {
			return nil
		}

		log.Printf("Image in state %s, sleeping 2s before checking again",
			imageResp.Images[0].State)
		time.Sleep(2 * time.Second)
	}
}

// WaitForAMI waits for the given AMI ID to become ready.
func WaitForAMI(c *ec2.EC2, imageId string) error {
	for {
		imageResp, err := c.Images([]string{imageId}, ec2.NewFilter())
		if err != nil {
			if ec2err, ok := err.(*ec2.Error); ok && ec2err.Code == "InvalidAMIID.NotFound" {
				log.Println("AMI not found, probably state issues on AWS side. Trying again.")
				continue
			}

			return err
		}

		if imageResp.Images[0].State == "available" {
			return nil
		}

		log.Printf("Image in state %s, sleeping 2s before checking again",
			imageResp.Images[0].State)
		time.Sleep(2 * time.Second)
	}
}

// purgeAMIs purges AMIs based on specified windows
func purgeAMIs(awsec2 *ec2.EC2, instanceNameTag string, windows []window, s *session) error {
	filter := ec2.NewFilter()
	filter.Add("tag:hostname", instanceNameTag)
	imageList, err := awsec2.Images(nil, filter)
	if err != nil {
		return fmt.Errorf("EC2 API Images failed: %s", err.Error())
	}
	s.debug(fmt.Sprintf("Found %d total images for %s in %s", len(imageList.Images), instanceNameTag, awsec2.Region.Name))
	images := map[string]time.Time{}
	for _, image := range imageList.Images {
		timestampTag := ""
		for _, tag := range image.Tags {
			if tag.Key == "timestamp" {
				timestampTag = tag.Value
			}
		}
		if len(timestampTag) < 1 {
			s.debug(fmt.Sprintf("AMI is missing timestamp tag - skipping: %s", image.Id))
			continue
		}
		timestamp, err := strconv.ParseInt(timestampTag, 10, 64)
		if err != nil {
			s.debug(fmt.Sprintf("AMI timestamp tag is corrupt - skipping: %s", image.Id))
			continue
		}
		images[image.Id] = time.Unix(timestamp, 0)
	}
	for _, window := range windows {
		s.debug(fmt.Sprintf("Window: 1 per %s from %s-%s", window.interval.String(), window.start, window.stop))
		for cursor := window.start; cursor.Before(window.stop); cursor = cursor.Add(window.interval) {
			imagesInThisInterval := []string{}
			imagesTimes := make(map[string]time.Time)
			oldestImage := ""
			oldestImageTime := time.Now()
			for id, when := range images {
				if when.After(cursor) && when.Before(cursor.Add(window.interval)) {
					imagesInThisInterval = append(imagesInThisInterval, id)
					imagesTimes[id] = when
					if when.Before(oldestImageTime) {
						oldestImageTime = when
						oldestImage = id
					}
				}
			}
			if len(imagesInThisInterval) > 1 {
				for _, id := range imagesInThisInterval {
					if id == oldestImage { // keep the oldest one
						s.debug(fmt.Sprintf("Keeping oldest AMI in this window: %s @ %s (%s->%s)", id, imagesTimes[id].Format(timeShortFormat), window.start.Format(timeShortFormat), window.stop.Format(timeShortFormat)))
						continue
					}
					// find snapshots associated with this AMI.
					snaps, err := findSnapshots(id, awsec2)
					if err != nil {
						return fmt.Errorf("EC2 API findSnapshots failed for %s: %s", id, err.Error())
					}
					// deregister the AMI.
					resp, err := awsec2.DeregisterImage(id)
					if err != nil {
						return fmt.Errorf("EC2 API DeregisterImage failed for %s: %s", id, err.Error())
					}
					if resp.Return != true {
						return fmt.Errorf("EC2 API DeregisterImage error for %s", id)
					}
					// delete snapshots associated with this AMI.
					for snap, _ := range snaps {
						if _, err := awsec2.DeleteSnapshots([]string{snap}); err != nil {
							return fmt.Errorf("EC2 API DeleteSnapshot failed: %s", err.Error())
						}
					}
					s.debug(fmt.Sprintf("Purged old AMI %s @ %s (%s->%s)", id, imagesTimes[id].Format(timeShortFormat), window.start.Format(timeShortFormat), window.stop.Format(timeShortFormat)))
				}
			}
		}
	}
	return nil
}

// createAMIs actually creates the AMI(s)
func createAMIs(awsec2 *ec2.EC2, instances []ec2.Instance, s *session) map[string]string {
	newAMIs := make(map[string]string)
	pendingAMIs := make(map[string]bool)
	for _, instance := range instances {
		backupAmiName := fmt.Sprintf("%s-%s-%s", s.instanceNameTag, timeStamp, instance.InstanceId)
		backupDesc := fmt.Sprintf("%s %s %s", s.instanceNameTag, timeString, instance.InstanceId)
		blockDevices := []ec2.BlockDeviceMapping{}
		for _, i := range s.ignoreVolumes {
			blockDevices = append(blockDevices, ec2.BlockDeviceMapping{DeviceName: i, NoDevice: true})
		}
		createOpts := ec2.CreateImage{
			InstanceId:   instance.InstanceId,
			Name:         backupAmiName,
			Description:  backupDesc,
			NoReboot:     true,
			BlockDevices: blockDevices,
		}
		resp, err := awsec2.CreateImage(&createOpts)
		if err != nil {
			s.fatal(fmt.Sprintf("Error creating new AMI: %s", err.Error()))
		}
		_, err = awsec2.CreateTags([]string{resp.ImageId}, []ec2.Tag{
			{"hostname", s.instanceNameTag},
			{"instance", instance.InstanceId},
			{"date", timeString},
			{"timestamp", timeSecs},
		})
		if err != nil {
			s.fatal(fmt.Sprintf("Error tagging new AMI: %s", err.Error()))
		}
		newAMIs[resp.ImageId] = instance.InstanceId
		pendingAMIs[resp.ImageId] = true
		s.debug(fmt.Sprintf("Creating new AMI %s for %s (%s)", resp.ImageId, s.instanceNameTag, instance.InstanceId))
	}

	// wait for AMIs to be ready
	done := make(chan bool)
	go func() {
		for len(pendingAMIs) > 0 {
			s.debug(fmt.Sprintf("Sleeping for %d pending AMIs", len(pendingAMIs)))
			time.Sleep(apiPollInterval)
			list := []string{}
			for k, _ := range pendingAMIs {
				list = append(list, k)
			}
			images, err := awsec2.Images(list, nil)
			if err != nil {
				s.fatal("EC2 API Images failed")
			}
			for _, image := range images.Images {
				if image.State == "available" {
					delete(pendingAMIs, image.Id)
					s.ok(fmt.Sprintf("Created new AMI %s", image.Id))
				}
			}
		}
		done <- true
	}()
	select {
	case <-done:
	case <-time.After(s.timeout):
		list := []string{}
		for k, _ := range pendingAMIs {
			list = append(list, k)
		}
		s.fatal(fmt.Sprintf("Timeout waiting for AMIs in region %s: %s", s.sourceRegion.Name, strings.Join(list, " ,")))
	}
	return newAMIs
}