serverless.yml

resources:
  Resources:
    IamRoleLambda:
      Type: 'AWS::IAM::Role'
      Properties:
        AssumeRolePolicyDocument:
          Version: '2012-10-17'
          Statement:
            -
              Effect: Allow
              Principal:
                Service: [lambda.amazonaws.com]
              Action:
                - 'sts:AssumeRole'
        Path: /
    IamPolicyLambda:
      Type: 'AWS::IAM::Policy'
      Properties:
        PolicyName: '${stage}-${service}-lambda'
        PolicyDocument:
          Version: '2012-10-17'
          Statement:
            -
              Effect: Allow
              Action:
                - 'logs:CreateLogGroup'
                - 'logs:CreateLogStream'
                - 'logs:PutLogEvents'
              Resource: 'arn:aws:logs:${region}:*:*'
            -
              Effect: Allow
              Action:
                - '*'
              Resource: 'arn:aws:dynamodb:*'
        Roles:
          -
            Ref: IamRoleLambda
    IamPolicyLambdaInvocationDynamoDB:
      Type: 'AWS::IAM::Policy'
      Properties:
        PolicyName: '${stage}-${service}-dynamo-stream-lambda'
        PolicyDocument:
          Version: '2012-10-17'
          Statement:
            -
              Effect: Allow
              Action:
                - 'lambda:InvokeFunction'
              Resource: '*'
            -
              Effect: Allow
              Action:
                - 'dynamodb:DescribeStream'
                - 'dynamodb:GetRecords'
                - 'dynamodb:GetShardIterator'
                - 'dynamodb:ListStreams'
                - 'dynamodb:PutItem'
                - 'dynamodb:GetItem'
              Resource: 'arn:aws:dynamodb:*'
        Roles:
          -
            Ref: IamRoleLambda
    dynamoDBTable:
      Type: AWS::DynamoDB::Table
      Properties:
        TableName: '${service}-tableName-${stage}'
        AttributeDefinitions:
          -
            AttributeName: Id
            AttributeType: S
        KeySchema:
          -
            AttributeName: Id
            KeyType: HASH
        ProvisionedThroughput:
          ReadCapacityUnits: 5
          WriteCapacityUnits: 5
        StreamSpecification:
          StreamViewType: NEW_IMAGE
    mapping:
      Type: AWS::Lambda::EventSourceMapping
      Properties:
        BatchSize: 10
        EventSourceArn:
          Fn::GetAtt:
            - dynamoDBTable
            - StreamArn
        FunctionName: '<lambda function ARN>'
        StartingPosition: TRIM_HORIZON