---
AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::Serverless-2016-10-31
Description: An Lambda function with a monitoring alarm, DLQ & PreTraffic Test
Metadata:
  License: magnet:?xt=urn:btih:1f739d935676111cfff4b4693e3816e664797050&dn=gpl-3.0.txt GPL-v3-or-Later
  cfn-lint:
    config:
      ignore_checks:
        - W3011  # UpdatePolicy generated by SAM

Parameters:
  NotificationEmail:
    Type: String
  TestData:
    Type: String
  TestExpected:
    Type: String

Resources:
  Function:
    Type: AWS::Serverless::Function
    Properties:
      Handler: lambda_function.handler
      Runtime: python3.7
      CodeUri: src/lambda_function.py
      DeadLetterQueue:
        TargetArn: !GetAtt DeadLetterQueue.Arn
        Type: SQS
      AutoPublishAlias: live
      DeploymentPreference:
        Type: CodeDeployDefault.LambdaAllAtOnce
        Alarms:
          - !Ref Alarm
        Hooks:
          PreTraffic: !Ref TestFunction


  Alarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      ActionsEnabled: true
      AlarmActions:
        - !Ref NotificationTopic
      AlarmDescription: Notify on failures of cloud-interest-rate-calculator function
      AlarmName: !Sub ${AWS::StackName}-errors
      MetricName: Errors
      Namespace: AWS/Lambda
      Statistic: Sum
      Dimensions:
        - Name: FunctionName
          Value: !Select [6, !Split [':', !GetAtt Function.Arn]]
        - Name: Resource
          Value: !Select [6, !Split [':', !GetAtt Function.Arn]]
      Period: 300
      EvaluationPeriods: 1
      DatapointsToAlarm: 1
      Threshold: 0
      ComparisonOperator: GreaterThanThreshold

  NotificationTopic:
    Type: AWS::SNS::Topic
    Properties:
      DisplayName: !Sub ${AWS::StackName}-errors
      Subscription:
        - Endpoint: !Ref NotificationEmail
          Protocol: email
      Tags:
        - Key: Type
          Value: Monitoring

  DeadLetterQueue:
    Type: AWS::SQS::Queue
    Properties:
      Tags:
        - Key: Type
          Value: DeadLetterQueue

  TestFunction:
    Type: AWS::Serverless::Function
    Properties:
      FunctionName: !Sub CodeDeployHook_PreHook_${AWS::StackName}
      Handler: lambda_verification.handler
      Runtime: python3.7
      CodeUri: src/lambda_verification.py
      Environment:
        Variables:
          CurrentVersion: !Ref Function.Version
          TestData: !Ref TestData
          TestExpected: !Ref TestExpected
      Policies:
        - Version: 2012-10-17
          Statement:
            - Effect: Allow
              Action: codedeploy:PutLifecycleEventHookExecutionStatus
              Resource: "*"
            - Effect: Allow
              Action: lambda:InvokeFunction
              Resource: !Sub "${Function.Arn}:*"

Outputs:
  LambdaArn:
    Value: !GetAtt Function.Arn