# Using the Amazon AppConfig deployment events to Amazon SNS extension
<a name="working-with-appconfig-extensions-about-predefined-notification-sns"></a>

The `Amazon AppConfig deployment events to Amazon SNS` extension is an Amazon authored extension that helps you monitor and act on the Amazon AppConfig configuration deployment workflow. The extension publishes messages to an Amazon SNS topic whenever a configuration is deployed. After you associate the extension to one of your Amazon AppConfig applications, environments, or configuration profiles, Amazon AppConfig publishes a message to the topic after every configuration deployment start, end, and rollback.

If you want more control over which action points send Amazon SNS notifications, you can create a custom extension and enter an Amazon SNS topic Amazon Resource Name (ARN) for the URI field. For information about creating an extension, see [Walkthrough: Creating custom Amazon AppConfig extensions](working-with-appconfig-extensions-creating-custom.md).

## Using the extension
<a name="working-with-appconfig-extensions-about-predefined-notification-sns-using"></a>

This section describes how to use the `Amazon AppConfig deployment events to Amazon SNS` extension.

**Step 1: Configure Amazon AppConfig to publish messages to a topic**  
Add an access control policy to your Amazon SNS topic granting Amazon AppConfig (`appconfig.amazonaws.com`) publish permissions (`sns:Publish`). For more information, see [Example cases for Amazon SNS access control](https://docs.amazonaws.cn/sns/latest/dg/sns-access-policy-use-cases.html).

**Step 2: Create an extension association**  
Attach the extension to one of your Amazon AppConfig resources by creating an extension association. You create the association by using the Amazon AppConfig console or the [CreateExtensionAssociation](https://docs.amazonaws.cn/appconfig/2019-10-09/APIReference/API_CreateExtensionAssociation.html) API action. When you create the association, you specify the ARN of an Amazon AppConfig application, environment, or configuration profile. If you associate the extension to an application or an environment, a notification is sent for any configuration profile contained within the specified application or environment. When you create the association, you must enter a value for the `topicArn` parameter that contains the ARN of the Amazon SNS topic you want to use.

After you create the association, when a configuration for the specified Amazon AppConfig resource is deployed, Amazon AppConfig invokes the extension and sends notifications according to the action points specified in the extension.

**Note**  
This extension is invoked by the following action points:  
`ON_DEPLOYMENT_START`
`ON_DEPLOYMENT_COMPLETE`
`ON_DEPLOYMENT_ROLLED_BACK`
You can't customize the actions points for this extension. To invoke different action points, you can create your own extension. For more information, see [Walkthrough: Creating custom Amazon AppConfig extensions](working-with-appconfig-extensions-creating-custom.md).

Use the following procedures to create an Amazon AppConfig extension association by using either the Amazon Systems Manager console or the Amazon CLI.

**To create an extension association (console)**

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

1. In the navigation pane, choose **Amazon AppConfig**.

1. On the **Extensions** tab, choose **Add to resource**.

1. In the **Extension resource details** section, for **Resource type**, choose an Amazon AppConfig resource type. Depending on the resource you choose, Amazon AppConfig prompts you to choose other resources.

1. Choose **Create association to resource**.

Here's a sample of the message sent to the Amazon SNS topic when the extension is invoked.

```
{
    "Type": "Notification",
    "MessageId": "ae9d702f-9a66-51b3-8586-2b17932a9f28",
    "TopicArn": "arn:aws:sns:us-east-1:111122223333:MySNSTopic",
    "Message": {
        "InvocationId": "7itcaxp",
        "Parameters": {
            "topicArn": "arn:aws:sns:us-east-1:111122223333:MySNSTopic"
        },
        "Application": {
            "Id": "1a2b3c4d",
            "Name": MyApp
        },
        "Environment": {
            "Id": "1a2b3c4d",
            "Name": MyEnv
        },
        "ConfigurationProfile": {
            "Id": "1a2b3c4d",
            "Name": "MyConfigProfile"
        },
        "Description": null,
        "DeploymentNumber": "3",
        "ConfigurationVersion": "1",
        "Type": "OnDeploymentComplete"
    },
    "Timestamp": "2022-06-30T20:26:52.067Z",
    "SignatureVersion": "1",
    "Signature": "<...>",
    "SigningCertURL": "<...>",
    "UnsubscribeURL": "<...>",
    "MessageAttributes": {
        "MessageType": {
            "Type": "String",
            "Value": "OnDeploymentStart"
        }
    }
}
```