Amazon Kinesis Data Firehose - AWS Lambda data transformation app (YAML)

template.yml

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

Resources:
  DeliveryBucket:
    Type: AWS::S3::Bucket

  StreamProcessFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: handler.lambda_handler
      Runtime: python2.7
      # ... 
      # all the other properties here
      # ... 

  DeliveryStream:
    Type: AWS::KinesisFirehose::DeliveryStream
    DependsOn:
      - DeliveryStreamPolicy
    Properties:
      DeliveryStreamType: DirectPut
      ExtendedS3DestinationConfiguration:
        Prefix: firehose/
        BucketARN: !GetAtt DeliveryBucket.Arn
        BufferingHints:
          IntervalInSeconds: 60
          SizeInMBs: 10
        CompressionFormat: GZIP
        RoleARN: !GetAtt DeliveryStreamRole.Arn
        ProcessingConfiguration:
          Enabled: true
          Processors:
            - Type: Lambda
              Parameters:
                - ParameterName: LambdaArn
                  ParameterValue: !GetAtt StreamProcessFunction.Arn

  DeliveryStreamRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Sid: 'firehose-assume-role'
            Effect: Allow
            Principal:
              Service: firehose.amazonaws.com
            Action: 'sts:AssumeRole'
            Condition:
              StringEquals:
                'sts:ExternalId': !Ref 'AWS::AccountId'

  DeliveryStreamPolicy:
    Type: AWS::IAM::Policy
    Properties:
      Roles:
        - !Ref DeliveryStreamRole
      PolicyName: firehose_delivery_policy
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - 's3:AbortMultipartUpload'
              - 's3:GetBucketLocation'
              - 's3:GetObject'
              - 's3:ListBucket'
              - 's3:ListBucketMultipartUploads'
              - 's3:PutObject'
            Resource:
              - !GetAtt DeliveryBucket.Arn
              - !Join 
                - ''
                - - 'arn:aws:s3:::'
                  - !Ref DeliveryBucket
                  - '*'
          - Effect: Allow
            Action:
              - 'lambda:InvokeFunction'
              - 'lambda:GetFunctionConfiguration'
            Resource: !GetAtt StreamProcessFunction.Arn