osls/docs/events/activemq.md

Open-source alternative to Serverless Framework

# ActiveMQ

An ActiveMQ message broker can be used as an event source for AWS Lambda.

## Simple event definition

In the following example, we specify that the `compute` function should be triggered whenever there are new messages available to consume from defined ActiveMQ `queue`.

In order to configure `activemq` event, you have to provide three required properties:

- `basicAuthArn`, which is a [AWS Secrets Manager](https://aws.amazon.com/secrets-manager/) ARN for credentials required to do basic auth to allow Lambda to connect to your message broker
- `queue` to consume messages from.
- `arn` arn for your Amazon MQ message broker

```yml
functions:
  compute:
    handler: handler.compute
    events:
      - activemq:
          arn: arn:aws:mq:us-east-1:0000:broker:ExampleMQBroker:b-xxx-xxx
          queue: queue-name
          basicAuthArn: arn:aws:secretsmanager:us-east-1:01234567890:secret:MySecret
```

## Enabling and disabling ActiveMQ event

The `activemq` event also supports `enabled` parameter, which is used to control if the event source mapping is active. Setting it to `false` will pause polling for and processing new messages.

In the following example, we specify that the `compute` function's `activemq` event should be disabled.

```yml
functions:
  compute:
    handler: handler.compute
    events:
      - activemq:
          arn: arn:aws:mq:us-east-1:0000:broker:ExampleMQBroker:b-xxx-xxx
          queue: queue-name
          enabled: false
          basicAuthArn: arn:aws:secretsmanager:us-east-1:01234567890:secret:MySecret
```

## Specifying batch size and batch window

You can also specify `batchSize` of number of items to retrieve in a single batch. If not specified, this will default to `100`.
Likewise `maximumBatchingWindow` can be set to determine the amount of time the Lambda spends gathering records before invoking the function. The default is 0, but **if you set `batchSize` to more than 10, you must set `maximumBatchingWindow` to at least 1**. The maximum is 300.

```yml
functions:
  compute:
    handler: handler.compute
    events:
      - activemq:
          arn: arn:aws:mq:us-east-1:0000:broker:ExampleMQBroker:b-xxx-xxx
          queue: queue-name
          batchSize: 5000
          maximumBatchingWindow: 30
          basicAuthArn: arn:aws:secretsmanager:us-east-1:01234567890:secret:MySecret
```

## Setting filter patterns

This configuration allows customers to filter event before lambda invocation. It accepts up to 5 filter criterion by default and up to 10 with quota extension. If one event matches at least 1 pattern, lambda will process it.

For more details and examples of filter patterns, please see the [AWS event filtering documentation](https://docs.aws.amazon.com/lambda/latest/dg/invocation-eventfiltering.html)

Note: Serverless only sets this property if you explicitly add it to the `activemqmsk` configuration (see an example below). The following example will only process records that are published in to Amazon MQ for Apache ActiveMQ where field `a` is equal to 1 or 2.

```yml
functions:
  compute:
    handler: handler.compute
    events:
      - activemq:
          arn: arn:aws:mq:us-east-1:0000:broker:ExampleMQBroker:b-xxx-xxx
          queue: queue-name
          basicAuthArn: arn:aws:secretsmanager:us-east-1:01234567890:secret:MySecret
          filterPatterns:
            - value:
                a: [1]
```

## IAM Permissions

The Serverless Framework will automatically configure the most minimal set of IAM permissions for you. However you can still add additional permissions if you need to. Read the official [AWS documentation](https://docs.aws.amazon.com/lambda/latest/dg/with-mq.html#events-mq-permissions) for more information about IAM Permissions for Amazon MQ events.