Custom post-launch actions - Application Migration Service

Custom post-launch actions

AWS Application Migration Service (AWS MGN) allows you to execute any SSM document that you like – public SSM document or ones you created and uploaded to your account.

You can configure a custom action to execute any SSM document that is available in your account.

Create action

To add a new customer action, go to the Post-launch actions settings and click Create action.

The page includes the following parameters:

  • Action name – The name of the action in AWS MGN, which should be intuitive and meaningful to your migration users.

  • Activate this action – Use this checkbox to activate or deactivate the custom action.

  • This action must be completed successfully before finalizing cutover – This checkbox will dictate whether or not the script will prevent the cutover.

  • System Manager document name – Select any Systems Manager document that is available for the specific account.

  • View in Systems Manager – Click to open System Managers and view additional information about the document.

  • Description – Add a description or keep the default.

  • Document version – Select which SSM document version to run. AWS MGN can run a default version, the latest version, or a specific version, according to your preferences.

  • Category – Select from various available categories including disaster recovery, security, validation, and more.

  • Order – Specify the order in which the actions will be executed. The lower the number, the earlier the action will be executed. 1–1,000 are reserved for predefined actions and 1,001–10,000 for custom actions. The numbers must be unique but don’t need to be consecutive.

  • Operating system – Select the source server's operating systems for which the custom action can be configured for. Note that if you associate a script with the wrong operating system, it will be skipped.

  • Creator – Who created the action. For custom actions, the default is always Me.

The Action parameters change according to the specific SSM document that is selected.

Note that for the instance ID parameter, you can choose to use the launch instance ID, in which case, AWS MGN will dynamically populate the value.


Only trusted, authorized users should have access to the parameter store. For enhanced security, ensure that users who do not have permissions to execute SSM documents / commands, do not have access to parameter store. Learn more about restricting access to Systems Manager parameters. Action parameters are stored in the SSM parameter store as regular strings. Changing parameters in the SSM Parameter store may impact the post launch action execution on target instances. We recommend you consider security implications, when choosing to use parameters that contain scripts or sensitive information, such as API keys and database passwords.

Edit each setting as required and then click Add action.

Edit action

Use this page to edit the parameters detailed in the Create action section.

Edit each setting as required and then click Save action.