Resources:
  MyLambdaFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: nodejs14.x
      CodeUri: ${codeuri}

      AutoPublishAlias: Live

      DeploymentPreference:
        Role:
          Fn::GetAtt: [DeploymentRole, Arn]
        Type: Canary10Percent5Minutes
        Alarms:
        - {Ref: NewVersionErrorsAlarm}
        - {Ref: AliasErrorsAlarm}
        - {Ref: FunctionErrorsAlarm}
#       Hooks:
       # These hooks just hang so we're commenting them out for now or the deployment waits on them forever
#         PreTraffic: {"Ref": "PreTrafficFunction"}
#         PostTraffic: {"Ref": "PostTrafficFunction"}

  DeploymentRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
        - Action:
          - sts:AssumeRole
          Effect: Allow
          Principal:
            Service:
            - codedeploy.amazonaws.com

      Policies:
      - PolicyName: root
        PolicyDocument:
          Version: '2012-10-17'
          Statement:
          - Effect: Allow
            Resource: '*'
            Action:
            - cloudwatch:DescribeAlarms
            - lambda:UpdateAlias
            - lambda:GetAlias
            - lambda:InvokeFunction
            - s3:Get*
            - sns:Publish

  FunctionErrorsAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      Namespace: AWS/Lambda
      MetricName: Error

      Dimensions:
      - Name: FunctionName
        Value:
          Fn::GetAtt: [MyLambdaFunction, Arn]

      Statistic: Maximum
      Period: 60
      EvaluationPeriods: 5
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Threshold: 1.0

  AliasErrorsAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      Namespace: AWS/Lambda
      MetricName: Error

      Dimensions:
      - Name: FunctionName
        Value:
          Fn::GetAtt: [MyLambdaFunction, Arn]
      - Name: Alias
        Value: Live

      Statistic: Maximum
      Period: 60
      EvaluationPeriods: 5
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Threshold: 1.0

 # Alarm pointing to the Errors metric on "latest" executed function version
 # When the deployment is happening, this alarm will point to the new version that ie being deployed
  NewVersionErrorsAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      Namespace: AWS/Lambda
      MetricName: Error

      Dimensions:
      - Name: FunctionName
        Value:
          Fn::GetAtt: [MyLambdaFunction, Arn]

      - Name: Alias
        Value: Live

      - Name: ExecutedVersion
        Value:
          Fn::GetAtt: [MyLambdaFunction.Version, Version]

      Statistic: Maximum
      Period: 60
      EvaluationPeriods: 5
      ComparisonOperator: GreaterThanOrEqualToThreshold
      Threshold: 1.0

  PreTrafficFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: nodejs14.x
      CodeUri: ${codeuri}

  PostTrafficFunction:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      Runtime: nodejs14.x
      CodeUri: ${codeuri}
Metadata:
  SamTransformTest: true