---
AWSTemplateFormatVersion: '2010-09-09'
Parameters:
  SlackChannel:
    Type: String
    Description: 'Please enter your Slack channel name:'
  HookURL:
    Type: String
    Description: 'Please enter the web hook url from Slack:'
    NoEcho: true
Resources:
  LambdaFunctionRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
        - Effect: Allow
          Principal:
            Service:
            - lambda.amazonaws.com
          Action:
          - sts:AssumeRole
      Path: "/"
  LambdaRolePolicies:
    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: LambdaFunctionRole
  SlackNotifierLambdaFn:
    Type: AWS::Lambda::Function
    Properties:
      Description: 'AWS PHD Slack Notifier'
      Handler: index.handler
      Role:
        Fn::GetAtt:
        - LambdaFunctionRole
        - Arn
      Code:
        ZipFile:
          Fn::Sub: |
            # Sample Lambda Function to post notifications to a slack channel when an AWS Health event happens
            from __future__ import print_function
            import boto3
            import json
            import logging
            import os
            from urllib.request import Request, urlopen, URLError, HTTPError
            from urllib.parse import urlencode
            # Setting up logging
            logger = logging.getLogger()
            logger.setLevel(logging.INFO)
            # main function
            def handler(event, context):
                message =  str(
                    event['detail']['eventDescription'][0]['latestDescription']  +
                    "\n\n<https://phd.aws.amazon.com/phd/home?region=us-east-1#/event-log?eventID=" +
                    event['detail']['eventArn'] +
                    "|Click here> for details."
                )
                json.dumps(message)
                slack_message = {
                  "channel": "${SlackChannel}",
                  "text": message,
                  "username": "AWS - Personal Health Updates"
                }
                logger.info(str(slack_message))
                req = Request(
                  "${HookURL}",
                  data=json.dumps(slack_message).encode("utf-8"),
                  headers={"content-type": "application/json"}
                )
                try:
                  response = urlopen(req)
                  response.read()
                  logger.info("Message posted to: %s", slack_message['channel'])
                except HTTPError as e:
                   logger.error("Request failed : %d %s", e.code, e.reason)
                except URLError as e:
                   logger.error("Server connection failed: %s", e.reason)
      Runtime: python3.7
      Timeout: '60'
  LambdaInvokePermission:
    Type: AWS::Lambda::Permission
    Properties:
      FunctionName:
        Fn::GetAtt:
        - SlackNotifierLambdaFn
        - Arn
      Action: lambda:InvokeFunction
      Principal: events.amazonaws.com
      SourceArn:
        Fn::GetAtt:
        - CloudWatchEventRule
        - Arn
  CloudWatchEventRule:
    Type: AWS::Events::Rule
    Properties:
      Description: EventRule
      EventPattern:
        source:
        - aws.health
      State: ENABLED
      Targets:
      - Arn:
          Fn::GetAtt:
          - SlackNotifierLambdaFn
          - Arn
        Id: SlackNotifierLambdaFn