cloud-formation.yaml

AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::Serverless-2016-10-31


Resources:
  # --------------Lambda Layer containing the Atlas binary --------------- #
  AtlasLayer:
    Type: AWS::Serverless::LayerVersion
    Properties:
      Description: Lambda layer to contain the Atlas binary for DB schema migration
      ContentUri: atlas_layer
      CompatibleRuntimes:
        - python3.11

  # --------------Schema Migration Lambda triggered by Custom Resource--------------- #
  SchemaMigrationLambda:
    Type: AWS::Serverless::Function
    Properties:
      Description: Lambda triggered by custom resource to run DB schema migrations
      CodeUri: ../src/
      Handler: migration_lambda.aws.lambda_handler
      Runtime: python3.12
      Layers:
        - !Ref AtlasLayer
      MemorySize: 256
      Tracing: Active
      AutoPublishAlias: live
      Timeout: 900
      Environment:
        Variables:
          DB_HOST: <SET VALUE>
          DB_PORT: <SET VALUE>
          DB_NAME: <SET VALUE>
          DB_USER: <SET VALUE>
      Policies:
        - <ARN of policy for allowing RDS proxy connection>
      VpcConfig:
        SecurityGroupIds:
          - <ID of security group to allow connection to DB>
        SubnetIds: <List of subnet IDs that DB exists in>

  # A custom resource which triggers the Lambda to run the schema migrations
  MigrationTrigger:
    Type: AWS::CloudFormation::CustomResource
    Properties:
      ServiceToken: !GetAtt SchemaMigrationLambda.Arn
      # 15 minute timeout to correspond with maximum Lambda duration
      ServiceTimeout: 900
      # When this value changes, it will cause an update to this custom resource and therefore cause migrations to run
      MigrationHash: 4M4XVqDlARAEnO10mHon8QQh4yKV5rYIHk+OGarK5Qk=
      ForceUpdate: 1  # Change this value to force apply migrations, even if the migration files have not changed

  LambdaLogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub '/aws/lambda/${SchemaMigrationLambda}'
      RetentionInDays: 30