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

Parameters:
  ApiStageName:
    Type: String
    Default: dev
    Description: "The API Gateway Stage name (e.g. dev, prod, etc.)"
  FirehoseS3Prefix:
    Type: String
    Default: firehose/
    Description: "The S3 Key prefix for Kinesis Firehose."
  FirehoseCompressionFormat:
    Type: String
    Default: GZIP
    AllowedValues: [UNCOMPRESSED, GZIP, Snappy]
    Description: "Compression format used by Kinesis Firehose"
  FirehoseBufferingInterval:
    Type: Number
    Default: 60
    MinValue: 60
    MaxValue: 900
    Description: "How long Firehose will wait before writing a new batch into S3"
  FirehoseBufferingSize:
    Type: Number
    Default: 10
    MinValue: 1
    MaxValue: 128
    Description: "Maximum batch size in MB"
  LambdaTimeout:
    Type: Number
    Default: 30
    MinValue: 5
    MaxValue: 300
    Description: "Maximum Lambda execution time in seconds"
  LambdaMemorySize:
    Type: String
    Default: 1024
    AllowedValues: [128,192,256,320,384,448,512,576,640,704,768,832,896,960,1024,1088,1152,1216,1280,1344,1408,1472,1536]
  AthenaDatabaseName:
    Type: String
    Default: serverless_data_pipeline
    Description: "The Athena database name"
  AthenaTableName:
    Type: String
    Default: records
    Description: "The Athena table name"
  ProjectId:
    Type: String
    Description: CodeStar projectId used to associate new resources to team members
    Default: atum

Resources:
  DeliveryBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: !Sub '${ProjectId}-firehose'

  # StreamProcessFunction:
  #   Type: AWS::Serverless::Function
  #   Properties:
  #     Handler: handler.lambda_handler
  #     Runtime: python2.7
  #     Timeout: !Ref LambdaTimeout
  #     MemorySize: !Ref LambdaMemorySize

  StreamProcessFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: !Sub '${ProjectId}-cw-subscription-filter'
      CodeUri: function
      Handler: lambda_function.lambda_handler
      Runtime: python3.8
      Policies:
        - CloudWatchPutMetricPolicy: {}
  PostWeightSubscriptionFilter:
    Type: AWS::Logs::SubscriptionFilter
    Properties:
      DestinationArn: !GetAtt StreamProcessFunction.Arn
        # !Join
        #   - ''
        #   - - !Sub arn:aws:lambda:${AWS::Region}:${AWS::AccountId}:function:
        #   - - !Ref StreamProcessFunction
      FilterPattern: ""
      LogGroupName: !Sub /aws/lambda/${ProjectId}-post-weight
        # !Join
        #   - ''
        #   - - /aws/lambda/
        #     - !Ref StreamProcessFunction
  LambdaPermission:
    Type: AWS::Lambda::Permission
    Properties: 
      Action: lambda:InvokeFunction
      FunctionName: !GetAtt StreamProcessFunction.Arn
      Principal: logs.ap-northeast-1.amazonaws.com
      SourceArn: 
        !Join
          - ''
          - - !Sub arn:aws:logs:${AWS::Region}:${AWS::AccountId}:log-group:*:* #/aws/lambda/${ProjectId}-post-weight
            # - :live

  DeliveryStream:
    Type: AWS::KinesisFirehose::DeliveryStream
    DependsOn:
      - DeliveryStreamPolicy
    Properties:
      DeliveryStreamType: DirectPut
      ExtendedS3DestinationConfiguration:
        Prefix: !Ref FirehoseS3Prefix
        BucketARN: !GetAtt DeliveryBucket.Arn
        BufferingHints:
          IntervalInSeconds: !Ref FirehoseBufferingInterval
          SizeInMBs: !Ref FirehoseBufferingSize
        CompressionFormat: !Ref FirehoseCompressionFormat
        #EncryptionConfiguration: 
        #  KMSEncryptionConfig:
        #    AWSKMSKeyARN: ARN
        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: ''
            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: !Sub ${ProjectId}-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

import boto3
import gzip
import json
import logging
import os
import base64
# from StringIO import StringIO
from io import StringIO

firehose = boto3.client('firehose')


def lambda_handler(event, context):
    print(event)

    # encodedLogsData = event['awslogs']['data']
    # print(encodedLogsData)
    # print(type(encodedLogsData))
    # print(encodedLogsData.decode('base64'))
    # decodedLogsData = gzip.GzipFile(fileobj=StringIO(encodedLogsData.decode('base64', 'strict'))).read()
    # allEvents = json.loads(decodedLogsData)
    decoded_data = base64.b64decode(event['awslogs']['data'])
    json_data = json.loads(gzip.decompress(decoded_data))
    print(json_data)

    records = []

    for event in allEvents['logEvents']:

        logEvent = {
            'Data': str(event['message']) + "\n"
        }

        records.insert(len(records), logEvent)

        if len(records) > 499:
            firehose.put_record_batch(
                DeliveryStreamName=os.environ['DELIVERY_STREAM_NAME'],
                Records=records
            )

            records = []

    if len(records) > 0:
        firehose.put_record_batch(
            DeliveryStreamName=os.environ['DELIVERY_STREAM_NAME'],
            Records=records
        )

PostWeightSubscriptionFilter:
    Type: AWS::Logs::SubscriptionFilter
    Properties:
      DestinationArn: !GetAtt DeliveryStream.Arn # StreamProcessFunction.Arn
        # !Join
        #   - ''
        #   - - !Sub arn:aws:lambda:${AWS::Region}:${AWS::AccountId}:function:
        #   - - !Ref StreamProcessFunction
      FilterPattern: ""
      LogGroupName: !Sub /aws/lambda/${ProjectId}-post-weight
        # !Join
        #   - ''
        #   - - /aws/lambda/
        #     - !Ref StreamProcessFunction
      RoleArn: !GetAtt CWLRole.Arn
  CWLRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Sid: 'aaaaaaaaaaaaaa'
            Effect: Allow
            Principal:
              Service: logs.ap-northeast-1.amazonaws.com
            Action: 'sts:AssumeRole'
            # Condition:
            #   StringEquals:
            #     'sts:ExternalId': !Sub ${AWS::AccountId}

  CWLPolicy:
    Type: AWS::IAM::Policy
    Properties:
      Roles:
        - !Ref CWLRole
      PolicyName: !Sub ${ProjectId}-cwl-subscription-policy
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - 'firehose:*'
              - 'kinesis:*'
            Resource: !GetAtt DeliveryStream.Arn