osbuild-service-maintenance: implement removal of launch templates

Launch templates of instances that are terminated should be removed.
HMS-3632

cmd/osbuild-service-maintenance/aws.go

@@ -122,6 +122,14 @@ func AWSCleanup(maxConcurrentRequests int, dryRun bool, accessKeyID, accessKey s
 		}
 	}
 
+	errLaunchTemplates := searchLTAndCleanup(ctx, a, dryRun)
+	if errLaunchTemplates != nil {
+		logrus.Errorf("Error in cleaning up launch templates: %v", errLaunchTemplates)
+		if err != nil {
+			err = fmt.Errorf("Multiple errors while processing AWSCleanup: %w and %w.", err, errLaunchTemplates)
+		}
+	}
+
 	return err
 }
 
@@ -268,3 +276,39 @@ func allTerminated(reservations []ec2types.Reservation) bool {
 	return true
 }
 
+func searchLTAndCleanup(ctx context.Context, a *awscloud.AWS, dryRun bool) error {
+	launchTemplates, err := a.DescribeLaunchTemplatesByPrefix(ctx, "launch-template-for-i-")
+	if err != nil {
+		return err
+	}
+
+	for _, lt := range launchTemplates {
+		if lt.LaunchTemplateName == nil || lt.LaunchTemplateId == nil {
+			logrus.Errorf(
+				"Launch template needs to have a LaunchTemplateName (%v) and a LaunchTemplateId (%v).",
+				lt.LaunchTemplateName,
+				lt.LaunchTemplateId)
+			continue
+		}
+
+		reservations, err := a.DescribeInstancesByLaunchTemplateID(*lt.LaunchTemplateId)
+		if err != nil {
+			logrus.Errorf("Failed to describe launch template %s: %v", *lt.LaunchTemplateId, err)
+			continue
+		}
+
+		if allTerminated(reservations) {
+			logrus.Infof("Deleting launch template: %s (%s)\n", *lt.LaunchTemplateName, *lt.LaunchTemplateId)
+			if !dryRun {
+				err := a.DeleteLaunchTemplateById(ctx, lt.LaunchTemplateId)
+
+				if err != nil {
+					logrus.Errorf("Failed to delete launch template %s: %v", *lt.LaunchTemplateId, err)
+				}
+			}
+		} else {
+			fmt.Printf("Launch template %s has non terminated instances associated with it.\n", *lt.LaunchTemplateId)
+		}
+	}
+	return nil
+}

internal/cloud/awscloud/maintenance.go

@@ -93,6 +93,10 @@ func (a *AWS) DescribeInstancesBySecurityGroupID(securityGroupID string) ([]ec2t
 	return a.describeInstancesByKeyValue("instance.group-id", securityGroupID)
 }
 
+func (a *AWS) DescribeInstancesByLaunchTemplateID(launchTemplateID string) ([]ec2types.Reservation, error) {
+	return a.describeInstancesByKeyValue("tag:aws:ec2launchtemplate:id", launchTemplateID)
+}
+
 func (a *AWS) DescribeInstancesByInstanceID(instanceID string) ([]ec2types.Reservation, error) {
 	res, err := a.ec2.DescribeInstances(
 		context.Background(),
@@ -132,6 +136,22 @@ func (a *AWS) DescribeSecurityGroupsByPrefix(ctx context.Context, prefix string)
 	return securityGroups, nil
 }
 
+func (a *AWS) DescribeLaunchTemplatesByPrefix(ctx context.Context, prefix string) ([]ec2types.LaunchTemplate, error) {
+	var launchTemplates []ec2types.LaunchTemplate
+
+	ltOutput, err := a.ec2.DescribeLaunchTemplates(ctx, &ec2.DescribeLaunchTemplatesInput{})
+	if err != nil {
+		return launchTemplates, fmt.Errorf("failed to describe security groups: %w", err)
+	}
+
+	for _, lt := range ltOutput.LaunchTemplates {
+		if lt.LaunchTemplateName != nil && strings.HasPrefix(*lt.LaunchTemplateName, prefix) {
+			launchTemplates = append(launchTemplates, lt)
+		}
+	}
+	return launchTemplates, nil
+}
+
 func (a *AWS) DeleteSecurityGroupById(ctx context.Context, sgID *string) error {
 	_, err := a.ec2.DeleteSecurityGroup(
 		ctx,
@@ -141,3 +161,13 @@ func (a *AWS) DeleteSecurityGroupById(ctx context.Context, sgID *string) error {
 	)
 	return err
 }
+
+func (a *AWS) DeleteLaunchTemplateById(ctx context.Context, ltID *string) error {
+	_, err := a.ec2.DeleteLaunchTemplate(
+		ctx,
+		&ec2.DeleteLaunchTemplateInput{
+			LaunchTemplateId: ltID,
+		},
+	)
+	return err
+}