func()

in updater/aws.go [246:278]

• 32 lines of code
• 6 McCabe index (conditional complexity)

func (u *updater) drainInstance(containerInstance string) error {
	log.Printf("Starting drain on container instance %q", containerInstance)
	resp, err := u.ecs.UpdateContainerInstancesState(&ecs.UpdateContainerInstancesStateInput{
		Cluster:            &u.cluster,
		ContainerInstances: aws.StringSlice([]string{containerInstance}),
		Status:             aws.String("DRAINING"),
	})
	if err != nil {
		return fmt.Errorf("failed to change instance state to DRAINING: %w", err)
	}
	if len(resp.Failures) != 0 {
		log.Printf("There are API failures in draining the container instance %q, therefore attempting to"+
			" re-activate", containerInstance)
		err = u.activateInstance(containerInstance)
		if err != nil {
			log.Printf("Instance failed to re-activate after failing to change state to DRAINING: %v", err)
		}
		return fmt.Errorf("failures in API call: %v", resp.Failures)
	}
	log.Printf("Container instance state changed to DRAINING")

	err = u.waitUntilDrained(containerInstance)
	if err != nil {
		log.Printf("Container instance %q failed to drain, therefore attempting to re-activate", containerInstance)
		err2 := u.activateInstance(containerInstance)
		if err2 != nil {
			log.Printf("Instance failed to re-activate after failing to wait for drain to complete: %v", err2)
		}
		return fmt.Errorf("error while waiting to drain: %w", err)
	}
	log.Printf("Container instance %q drained successfully!", containerInstance)
	return nil
}