AWSTemplateFormatVersion: 2010-09-09
Parameters:
  CoralogixLogURL:
    Type: String
    Description: 'Please enter the Coralogix log URL endpoint:'
  PrivateKey:
    Type: String
    Description: |-
      A private key which is used to validate your authenticity
      Please enter your private key:
  AppName:
    Type: String
    Description: |-
      The name of your main application
      Please enter your app name:
  SubSystem:
    Type: String
    Description: |-
      Your application probably has multiple subsystems
      Please enter your sub system name:
Resources:
  CxNotifierLambdaRole:
    Type: 'AWS::IAM::Role'
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
            Action:
              - 'sts:AssumeRole'
      Path: /
  CxLambdaRolePolicies:
    Type: 'AWS::IAM::Policy'
    Properties:
      PolicyName: LambdaPolicy
      PolicyDocument:
        Version: 2012-10-17
        Statement:
          - Sid: Stmt12349896368829
            Action:
              - 'logs:CreateLogGroup'
              - 'logs:CreateLogStream'
              - 'logs:PutLogEvents'
            Effect: Allow
            Resource: 'arn:aws:logs:*:*:*'
      Roles:
        - !Ref CxNotifierLambdaRole
  CoralogixNotifierLambda:
    Type: 'AWS::Lambda::Function'
    Properties:
      Handler: index.lambda_handler
      Role: !GetAtt 
        - CxNotifierLambdaRole
        - Arn
      Code:
        ZipFile:
          Fn::Sub: |
            # Sample Lambda Function to post notifications to a slack channel when an AWS Health event happens
            import os
            import time
            import logging
            import json
            import urllib.error
            from urllib.request import Request, urlopen
            
            CORALOGIX_LOG_URL = os.getenv('CORALOGIX_LOG_URL')
            PRIVATE_KEY = os.getenv('PRIVATE_KEY')
            APP_NAME = os.getenv('APP_NAME')
            SUB_SYSTEM = os.getenv('SUB_SYSTEM')
            
            WARN = 4
            TIMEOUT = os.getenv('CORALOGIX_TIMEOUT_HTTP', 30)
            RETRIES = os.getenv('CORALOGIX_RETRIES_HTTP', 2)
            
            logger = logging.getLogger()
            logger.setLevel(logging.INFO)
            
            def lambda_handler(event, context):
                def send(e):
                    message = {
                        "privateKey": str(PRIVATE_KEY),
                        "applicationName": str(APP_NAME),
                        "subsystemName": str(SUB_SYSTEM),
                        "logEntries": [{"timestamp": (time.time() * 1000), "severity": WARN, "text": event}]
                    }
                    jsondata = json.dumps(message).encode('utf-8')
                    for attempt in range(int(RETRIES)):
                        try:
                            req = Request(CORALOGIX_LOG_URL)
                            req.add_header('Content-Type', 'application/json; charset=utf-8')
                            req.add_header('Content-Length', len(jsondata))
                            response = urlopen(req, data=jsondata,timeout=TIMEOUT)
                            if response.getcode() == 200:
                                logger.info("Health log published to Coralogix successfully 200 OK")
                                return True
                            else:
                                logger.error("health log publish failed, status code %d, %b", response.getcode(), response.read)
                        except urllib.error.URLError as e:
                            logger.error("URL Error %s", e)
                        except urllib.error.HTTPError as e:
                            logger.error("HTTP Error %s", e)
                        logger.info("attempt number %d", attempt + 1)
                        time.sleep(5)
            
                entities = event.get("detail", {}).get("affectedEntities")
                resources = event.get("resources")
                if(type(entities) == list and type(resources) == list and sorted(list(map(lambda x: x["entityValue"], entities)))  == sorted(resources) ):
                    event["detail"].pop("affectedEntities", None)
                    event.pop("resources", None)
                    for entity in entities:
                        event["detail"]["affectedEntity"] = entity
                        event["resource"] = entity.get("entityValue")
                        send(event)
                else:
                    send(event)
      Environment:
        Variables:
          CORALOGIX_LOG_URL: !Ref CoralogixLogURL
          PRIVATE_KEY: !Ref PrivateKey
          APP_NAME: !Ref AppName
          SUB_SYSTEM: !Ref SubSystem
      Tags:
        - Key: coralogix.com/monitor
          Value: 'true'
      Runtime: python3.8
      Timeout: '60'
  CxLambdaInvokePermission:
    Type: 'AWS::Lambda::Permission'
    Properties:
      FunctionName: !GetAtt 
        - CoralogixNotifierLambda
        - Arn
      Action: 'lambda:InvokeFunction'
      Principal: events.amazonaws.com
      SourceArn: !GetAtt 
        - CloudWatchRuleHealth
        - Arn
  CloudWatchRuleHealth:
    Type: 'AWS::Events::Rule'
    Properties:
      Description: EventRule for Coralogix
      EventPattern:
        source:
          - aws.health
      State: ENABLED
      Targets:
        - Arn: !GetAtt 
            - CoralogixNotifierLambda
            - Arn
          Id: CoralogixNotifierLambda