AWS Custom Resources

This repo contains collection of custom resources for using in CloudFormation templates.

Usage

1. Deploy particular stack from the collection into your account in region where you are going to use this custom resource.
2. Add custom resource with required configuration (see examples) into your target stack.

Stacks

AMI Info

src/ami-info-stack.yaml

This stack contains basic components for custom resource which allows you to find the newest ami image by specified filter parameters. It contains lambda function and a role for the lambda. To start you should deploy this stack to the region and the account where you want to use it, then add custom resource with desired search parameters into you stack:

AMIInfo:
  Type: Custom::AMIInfo
  Properties:
    ServiceToken: !ImportValue Custom--AMIInfoFunction--Arn
    Region: !Ref "AWS::Region"
    # 'DescribeParameters' contains named arguments for ec2.describe_images function
    DescribeParameters:
      Filters:
        - Name: name
          Values:
            - ami-name*

After that, you can get image id as follows: !GetAtt AMIInfo.ImageId. Full list of available attributes see in the docs for describe_images.

Aurora Cluster Info

src/aurora-cluster-info-stack.yaml

This stack contains basic components for custom resource which allows you to retrieve information about rds cluster by specified pattern for DBClusterIdentifier. It contains lambda function and a role for the lambda. To start you should deploy this stack to the region and the account where you want to use it, then add custom resource with desired search parameters into you stack:

AuroraClusterInfo:
  Type: Custom::AuroraClusterInfo
  Properties:
    ServiceToken: !ImportValue Custom--AuroraClusterInfoFunction--Arn
    Region: !Ref "AWS::Region"
    DBClusterIdentifierPattern: ^pre-stage-cluster.*

After that, you can get information as follows: !GetAtt AuroraClusterInfo.Endpoint. Full list of available attributes see in the docs for describe_db_clusters.

Lambda Configurator

src/lambda-configurator-stack.yaml

This stack contains basic components for custom resource which allows you to configure lambda concurrency limit during stack creation. It contains lambda function and a role for the lambda. To start you should deploy this stack to the region and the account where you want to use it, then add custom resource with two parameters (LambdaArn and ReservedConcurrentExecutions) into you stack:

LambdaConfigurator:
  Type: Custom::LambdaConfigurator
  Properties:
    ServiceToken: !ImportValue Custom--LambdaConfiguratorFunction--Arn
    Region: !Ref "AWS::Region"
    LambdaArn: !GetAtt TargetLambda.Arn
    ReservedConcurrentExecutions: 10