To use a custom AMI as a template

1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.
2. On the navigation bar at the top of the screen, the current AWS Region is displayed. Select a Region in which to launch your Auto Scaling group.
3. In the navigation pane, choose Instances.
4. Choose Launch instance, and then do the following:
   1. Under Name and tags, leave Name blank. The name isn’t part of the data that’s used to create a launch template.
   2. Under Application and OS Images (Amazon Machine Image), choose Browse more AMIs to browse the full AMI catalog.
   3. Choose My AMIs, find the AMI that you created, and then choose Select.
   4. Under Instance type, choose an instance type.

      Note

      Choose the same instance type that you used when you created the AMI or a more powerful one.

   5. On the right side of the screen, under Summary, for Number of instances, enter any number. The number that you enter here isn’t important. You will specify the number of instances that you want to launch when you create the Auto Scaling group.

      Under the Number of instances field, a message displays that says When launching more than 1 instance, consider EC2 Auto Scaling.

   6. Choose the consider EC2 Auto Scaling hyperlink text.
   7. On the Launch into Auto Scaling Group confirmation dialogue, choose Continue to go to the Create launch template page with the AMI and instance type you selected in the launch instance wizard already populated.

To create a launch template

1. Under Launch template name and description, enter a name and description for the new launch template.
2. (Optional) Under Key pair (login), for Key pair name, choose the name of the previously created key pair to use when connecting to instances, for example, using SSH.
3. (Optional) Under Network settings, for Security groups, choose one or more previously created security groups.
4. (Optional) Under Configure storage, update the storage configuration. The default storage configuration is determined by the AMI and the instance type.
5. When you are done configuring the launch template, choose Create launch template.
6. On the confirmation page, choose Create Auto Scaling group.

To create an Auto Scaling group

1. On the Choose launch template or configuration page, enter a name for the Auto Scaling group.
2. The launch template that you created is already selected for you.

   For Launch template version, choose whether the Auto Scaling group uses the default, the latest, or a specific version of the launch template when scaling out.

3. Choose Next to continue to the next step.
4. On the Choose instance launch options page, if you’re not using multiple instance types, you can skip the Instance type requirements section to use the EC2 instance type that is specified in the launch template.

   To use multiple instance types, see Auto Scaling groups with multiple instance types and purchase options.

5. Under Network, for VPC, choose a VPC. The Auto Scaling group must be created in the same VPC as the security group you specified in your launch template.

   Tip

   If you didn’t specify a security group in your launch template, your instances are launched with a default security group from the VPC that you specify. By default, this security group doesn’t allow inbound traffic from external networks.

6. For Availability Zones and subnets, choose one or more subnets in the specified VPC.
7. Choose Next twice to go to the Configure group size and scaling policies page.
8. Under Group size, define the Desired capacity (initial number of instances to launch immediately after the Auto Scaling group is created).
9. In the Scaling section, under Scaling limits, if your new value for Desired capacity is greater than Min desired capacity and Max desired capacity, the Max desired capacity is automatically increased to the new desired capacity value. You can change these limits as needed. For more information, see Set scaling limits for your Auto Scaling group.
10. Choose Skip to review.
11. On the Review page, choose Create Auto Scaling group.