// SendMessage sends an SNS message to an SNS region.
// See http://docs.aws.amazon.com/sdk-for-go/api/service/sns.html#type-PublishInput
func SendMessage(region string, topic string, subject string, message string) {
if region == "" {
log.Fatal("SNS region is required")
}
if topic == "" {
log.Fatal("SNS topic is required")
}
if subject == "" {
log.Fatal("SNS subject is required")
}
if message == "" {
log.Fatal("SNS message is required")
}
params := &sns.PublishInput{
Subject: aws.String(subject),
Message: aws.String(message),
TargetArn: aws.String(topic),
}
sns := sns.New(session.New(), aws.NewConfig().WithRegion(region))
_, err := sns.Publish(params)
awserror.HandleError(err)
}
// DestroySnapshots deletes snapshots greater than SnapshotManager's NumSnapshotsToRetain for a given volume
func (mgr *SnapshotManager) DestroySnapshots(volume *ec2.Volume) (snapshotsDestroyed int) {
if mgr.NumSnapshotsToRetain < 1 {
log.Fatal("NumSnapshotsToRetain should be great than 0")
}
params := &ec2.DescribeSnapshotsInput{
Filters: []*ec2.Filter{
{
Name: aws.String("volume-id"),
Values: []*string{
aws.String(*volume.VolumeId),
},
},
},
}
resp, err := mgr.ec2.DescribeSnapshots(params)
awserror.HandleError(err)
snapshots := resp.Snapshots
sort.Sort(ByStartTime(snapshots))
numberSnapshotsToDelete := len(snapshots) - mgr.NumSnapshotsToRetain
for numberSnapshotsToDelete > 0 {
params := &ec2.DeleteSnapshotInput{
SnapshotId: aws.String(*resp.Snapshots[numberSnapshotsToDelete-1].SnapshotId),
}
_, err := mgr.ec2.DeleteSnapshot(params)
if err != nil && err.(awserr.Error).Code() != "InvalidSnapshot.InUse" {
awserror.HandleError(err)
}
numberSnapshotsToDelete--
snapshotsDestroyed++
}
return snapshotsDestroyed
}
// TagResource creates tags for an EBS snapshot
func (mgr *SnapshotManager) TagResource(id *string, tags []*ec2.Tag) {
// remove tags containing "aws:", as these are reserved by AWS
// and cannot be duplicated for other resources
filteredTags := tags[:0]
for _, tag := range tags {
if !strings.Contains(*tag.Key, "aws:") {
filteredTags = append(filteredTags, tag)
}
}
params := &ec2.CreateTagsInput{
Resources: []*string{
aws.String(*id),
},
Tags: filteredTags,
}
_, err := mgr.ec2.CreateTags(params)
awserror.HandleError(err)
}
// CreateSnapshot creates an EBS snapshot for a specific EBS volume, optionally copying
// any volume tags depending on SnapshotManager's CopyVolumeTags. If the volume has a Name tag,
// it is used as the snapshot's description.
func (mgr *SnapshotManager) CreateSnapshot(volume *ec2.Volume) {
description := fmt.Sprintf("Snapshot for volume %s", *volume.VolumeId)
for _, tag := range volume.Tags {
if *tag.Key == "Name" {
description = *tag.Value
}
}
params := &ec2.CreateSnapshotInput{
Description: aws.String(description),
VolumeId: aws.String(*volume.VolumeId),
}
log.Printf("Starting snapshot for %s in region %s", *volume.VolumeId, mgr.Region)
snapshot, err := mgr.ec2.CreateSnapshot(params)
awserror.HandleError(err)
if mgr.CopyVolumeTags && len(volume.Tags) > 0 {
mgr.TagResource(snapshot.SnapshotId, volume.Tags)
}
}
// SnapshotVolumes is a helper method that wraps several operations. It queries for attached
// EBS volumes in the SnapshotManager's region, generates new snapshots, optionally
// copying any volume tags, and keeps the last X snapshots as specified by retainCount.
func (mgr *SnapshotManager) SnapshotVolumes() (snapshotsGenerated int) {
params := &ec2.DescribeVolumesInput{
Filters: []*ec2.Filter{
{
Name: aws.String("attachment.status"),
Values: []*string{
aws.String("attached"),
},
},
},
}
resp, err := mgr.ec2.DescribeVolumes(params)
awserror.HandleError(err)
for _, volume := range resp.Volumes {
mgr.CreateSnapshot(volume)
mgr.DestroySnapshots(volume)
snapshotsGenerated++
}
return snapshotsGenerated
}