// 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
}