func terminateASG(api *autoscaling.AutoScaling, instance *autoscaling.Group, wg *sync.WaitGroup) error {
defer wg.Done()
// 1. set the number of instances to 0
_, err := api.UpdateAutoScalingGroup(&autoscaling.UpdateAutoScalingGroupInput{
AutoScalingGroupName: instance.AutoScalingGroupName,
DesiredCapacity: aws.Int64(0),
MaxSize: aws.Int64(0),
MinSize: aws.Int64(0),
})
if err != nil {
return err
}
// 2. wait until the instance count is 0
for {
instances, err := api.DescribeAutoScalingGroups(&autoscaling.DescribeAutoScalingGroupsInput{
AutoScalingGroupNames: []*string{instance.AutoScalingGroupName},
})
if err != nil {
return err
}
// instance already deleted? we're done
if len(instances.AutoScalingGroups) == 0 {
return nil
}
// no instances remaining in asg? break
if v := instances.AutoScalingGroups[0]; len(v.Instances) == 0 {
break
}
time.Sleep(15 * time.Second)
}
// 3. terminate the asg
log.Printf("deleting autoscaling group, %s\n", *instance.AutoScalingGroupName)
_, err = api.DeleteAutoScalingGroup(&autoscaling.DeleteAutoScalingGroupInput{
AutoScalingGroupName: instance.AutoScalingGroupName,
ForceDelete: aws.Bool(true),
})
if err != nil {
return err
}
log.Printf("deleting launch configuration, %s\n", *instance.LaunchConfigurationName)
_, err = api.DeleteLaunchConfiguration(&autoscaling.DeleteLaunchConfigurationInput{
LaunchConfigurationName: instance.LaunchConfigurationName,
})
if err != nil {
return err
}
return nil
}
