Amazon EventBridge Policies for AWS Services as targets using CF/SAM

Question

I'm using AWS CloudFormation to setup an EventBridge Bus + Rules + Targets (say SNS). For SNS as a target, per the doc at https://docs.aws.amazon.com/eventbridge/latest/userguide/resource-based-policies-eventbridge.html#sns-permissions, I need to apply resource policies outside of CloudFormation and I don't think CF supports this yet?
For CW Logs Group as a target, Im using the aws logs put-resource-policy to set this up in a script. Is there a better way to automate this?

cloud jockey · Answer

Here is a snippet from my SAM:

{
  "MyDevQueue": {
    "Properties": {
      "QueueName": "my-dev-queue",
      "ReceiveMessageWaitTimeSeconds": 20,
      "Tags": [
        {
          "Key": "env",
          "Value": "dev"
        }
      ],
      "VisibilityTimeout": 300
    },
    "Type": "AWS::SQS::Queue"
  },
  "MyDevQueuePolicy": {
    "Properties": {
      "PolicyDocument": {
        "Statement": [
          {
            "Action": [
              "SQS:SendMessage"
            ],
            "Condition": {
              "ArnEquals": {
                "aws:SourceArn": "arn:aws:events:<region>:<AccountID>:rule/my-dev-queue/my-dev-queue"
              }
            },
            "Effect": "Allow",
            "Principal": {
              "Service": [
                "events.amazonaws.com"
              ]
            },
            "Resource": [
              {
                "Fn::GetAtt": [
                  "MyDevQueue",
                  "Arn"
                ]
              }
            ]
          }
        ]
      },
      "Queues": [
        "MyDevQueue"
      ]
    },
    "Type": "AWS::SQS::QueuePolicy"
  }
}

Answered by cloud jockey on December 20, 2021

Marcin · Answer

The link you've provided refers to setting up permissions for SNS topic. Setting such permissions is supported by the CloudFormation by means of AWS::SNS::TopicPolicy.
However, you also state that you want to set resource-based policies on the CloudWatch Logs (aws logs put-resource-policy). If this is the  case, then you are correct and it is not supported in CloudFormation.
You would have to use custom resource based on a lambda function to add such functionality to your templates.

Amazon EventBridge Policies for AWS Services as targets using CF/SAM

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