Auto Scaling With Email Notifications

We walk you through the steps of the basic scenario using the command line tools. You can also use the API actions that correspond to the command line calls. For more information, go to the Auto Scaling API Reference.

You will be using the following command line tool commands.

After you've created your Amazon SNS topic and you have the ARN, you are ready to set up the notification configuration. To configure your Auto Scaling group to send notifications when specified events take place, use as-put-notification-configuration.

The as-put-notification-configuration command takes the following arguments:

as-put-notification-configuration AutoScalingGroupName --notification-types value --topic-arn topic-ARN [General Options]

You need to specify the Auto Scaling group name, the ARN, and the notification types.

For this example, specify:

Open a command prompt and enter the as-put-notification-configuration command.

as-put-notification-configuration MyGroup --topic-arn arn:placeholder:MyTopic --notification-types autoscaling:EC2_INSTANCE_LAUNCH, autoscaling:EC2_INSTANCE_TERMINATE

Auto Scaling returns the following:

OK-Put Notification Configuration

You now have a notification configuration that sends a notification to the endpoint subscribed in the arn:placeholder:MyTopic ARN whenever instances are launched or terminated.

To verify the notification actions associated with your Auto Scaling group when specified events take place, use as-describe-notification-configurations.

The as-describe-notification-configurations command takes the following arguments:

as-describe-notification-configurations [--auto-scaling-groups value[,value...]] [--maxrecords value] [General Options]

If you specify the Auto Scaling group, this command returns a full list of all notification configuration for the Auto Scaling group listed. If you don't provide an Auto Scaling group name, the service returns the full details of all Auto Scaling groups. The command also returns a token if there are more pages to retrieve. To get the next page, call this action again with the returned token as the next-token argument. For this example, specify:

Open a command prompt and enter the as-describe-notification-configurations command.

as-describe-notification-configurations --auto-scaling-groups MyGroup -headers

Auto Scaling returns the following:

NOTIFICATION-CONFIG  GROUP-NAME  TOPIC-ARN  NOTIFICATION-TYPE-NAME
NOTIFICATION-CONFIG  MyGroup  arn:placeholder:MyTopic  autoscaling:EC2_INSTANCE_LAUNCH
NOTIFICATION-CONFIG  MyGroup  arn:placeholder:MyTopic  autoscaling:EC2_INSTANCE_TERMINATE

You have confirmed that you have a notification configuration set up for the MyGroup Auto Scaling group.

To cause the changes that will generate notifications, let's update the Auto Scaling group by changing the desired capacity of the MyGroup Auto Scaling group from 1 instance to 5 instances. When Auto Scaling launches the EC2 instances to the new desired capacity, SNS will send an email notification.

For this example, you will use as-set-desired-capacity command to change the desired capacity of the Auto Scaling group, and the as-describe-auto-scaling-groups to verify the instances of your Auto Scaling group.

The as-set-desired-capacity command takes the following arguments:

as-set-desired-capacity AutoScalingGroupName --desired-capacity value [--honor-cooldown|no-honor-cooldown] [General Options]

To use as-set-desired-capacity, you must specify the Auto Scaling group name (MyGroup) and the new number of instances as the desired capacity (5).

Open a command prompt and enter the commands.

as-set-desired-capacity MyGroup --desired-capacity 5

Auto Scaling returns the following:

OK-Desired Capacity Set

Within a few minutes of calling as-set-desired-capacity, you should get an email notification that instances for MyGroup were launched. When you receive this notification, you can confirm it by using as-describe-auto-scaling-groups and specifying MyGroup as the Auto Scaling group name.

Here's how you clean up when you're done: Delete the notification configuration, which we discuss in this section, and then delete the Auto Scaling group, which we discuss in the next section.

To delete the notification configuration, use as-delete-notification-configuration. The as-delete-notification-configuration command takes the following arguments:

as-delete-notification-configuration AutoScalingGroupNames --topic-ARN value [General Options]

Both the Auto Scaling group name and ARN are required. For this example, specify:

Open a command prompt and enter the command:

as-delete-notification-configuration MyGroup --topic-ARN arn:placeholder:MyTopic 

After confirming that you want to delete the notification configuration, Auto Scaling returns the following:

OK-Deleted Notification Configuration

To delete the Auto Scaling group, use as-delete-auto-scaling-group. Starting with API version 2011-01-01, you can use the new --force-delete argument to delete the Auto Scaling group and terminate all instances associated with it with one call. Previously, you would perform these two tasks by setting the desired capacity to zero (0), waiting until all instances are deleted, and then deleting the Auto Scaling group.

The as-delete-auto-scaling-group command takes the following arguments:

as-delete-auto-scaling-group AutoScalingGroupNames [--force-delete] [General Options]

In this example, we will use the optional --force-delete argument, so specify:

Open a command prompt and enter the commands:

as-delete-auto-scaling-group MyGroup --force-delete

After confirming that you want to delete the Auto Scaling group, Auto Scaling returns the following:

OK-Deleted Auto Scaling group

You have just deleted your notification configuration, instances, and Auto Scaling group. All that's left is the launch configuration you created in the Create a Launch Configuration section. To delete launch configurations, use the as-delete-launch-config CLI command with the launch configuration name.

The command looks like this:

as-delete-launch-config MyLC

For information on how to delete the SNS topic, go to DeleteTopic in the Amazon Simple Notification Service Getting Started Guide.

You just performed the following tasks:

Following is the complete snippet used to perform these tasks. You can copy the snippet, replace the values with your own, and use the code to get started.

as-put-notification-configuration MyGroup --topic-arn arn:placeholder:MyTopic --notification-types autoscaling:EC2_INSTANCE_LAUNCH, autoscaling:EC2_INSTANCE_TERMINATE
as-describe-notification-configurations MyGroup -headers
as-set-desired-capacity MyGroup --desired-capacity 5  
as-describe-auto-scaling-groups MyGroup
as-delete-notification-configuration MyGroup --topic-ARN arn:placeholder:MyTopic 
as-delete-auto-scaling-group MyGroup --force-delete