Creating a custom Amazon AppConfig extension - Amazon AppConfig
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Creating a custom Amazon AppConfig extension

An extension defines one or more actions that it performs during an Amazon AppConfig workflow. For example, the Amazon authored Amazon AppConfig deployment events to Amazon SNS extension includes an action to send a notification to an Amazon SNS topic. Each action is invoked either when you interact with Amazon AppConfig or when Amazon AppConfig is performing a process on your behalf. These are called action points. Amazon AppConfig extensions support the following action points:

  • PRE_CREATE_HOSTED_CONFIGURATION_VERSION

  • PRE_START_DEPLOYMENT

  • ON_DEPLOYMENT_START

  • ON_DEPLOYMENT_STEP

  • ON_DEPLOYMENT_BAKING

  • ON_DEPLOYMENT_COMPLETE

  • ON_DEPLOYMENT_ROLLED_BACK

Extension actions configured on PRE_* action points are applied after request validation, but before Amazon AppConfig performs the activity that corresponds to the action point name. These action invocations are processed at the same time as a request. If more than one request is made, action invocations run sequentially. Also note that PRE_* action points receive and can change the contents of a configuration. PRE_* action points can also respond to an error and prevent an action from happening.

An extension can also run in parallel with an Amazon AppConfig workflow by using an ON_* action point. ON_* action points are invoked asynchronously. ON_* action points don't receive the contents of a configuration. If an extension experiences an error during an ON_* action point, the service ignores the error and continues the workflow.

The following sample extension defines one action that calls the PRE_CREATE_HOSTED_CONFIGURATION_VERSION action point. In the Uri field, the action specifies the Amazon Resource Name (ARN) of the MyS3ConfigurationBackUpExtension Lambda function created earlier in this walkthrough. The action also specifies the Amazon Identity and Access Management (IAM) assume role ARN created earlier in this walkthrough.

Sample Amazon AppConfig extension

{
    "Name": "MySampleExtension",
    "Description": "A sample extension that backs up configurations to an S3 bucket.",
    "Actions": {
        "PRE_CREATE_HOSTED_CONFIGURATION_VERSION": [
            {
                "Name": "PreCreateHostedConfigVersionActionForS3Backup",
                "Uri": "arn:aws-cn:lambda:aws-region:111122223333:function:MyS3ConfigurationBackUpExtension",
                "RoleArn": "arn:aws-cn:iam::111122223333:role/ExtensionsTestRole"
            }
        ]
    },
    "Parameters" : {
        "S3_BUCKET": {
            "Required": false
        }
    }
}
Note

To view request syntax and field descriptions when creating an extension, see the CreateExtension topic in the Amazon AppConfig API Reference.

To create an extension (console)

  1. Open the Amazon Systems Manager console at https://console.amazonaws.cn/systems-manager/appconfig/.

  2. In the navigation pane, choose Amazon AppConfig.

  3. On the Extensions tab, choose Create extension.

  4. For Extension name, enter a unique name. For the purposes of this walkthrough, enter MyS3ConfigurationBackUpExtension. Optionally, enter a description.

  5. In the Actions section, choose Add new action.

  6. For Action name, enter a unique name. For the purposes of this walkthrough, enter PreCreateHostedConfigVersionActionForS3Backup. This name describes the action point used by the action and the extension purpose.

  7. In the Action point list, choose PRE_CREATE_HOSTED_CONFIGURATION_VERSION.

  8. For Uri, choose Lambda function and then choose the function in the Lambda function list. If you don't see your function, verify that you are in the same Amazon Web Services Region where you created the function.

  9. For IAM Role, choose the role you created earlier in this walkthrough.

  10. In the Extension parameters (optional) section, choose Add new parameter.

  11. For Parameter name, enter a name. For the purposes of this walkthrough, enter S3_BUCKET.

  12. Repeat steps 5–11 to create a second action for the PRE_START_DEPLOYMENT action point.

  13. Choose Create extension.