template.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Description: CD Demo Lambda

Resources:

  HelloWorld:
    Type: 'AWS::Serverless::Function'
    Properties:
      Handler: helloWorld.handler
      CodeUri: ./Lambda
      Runtime: nodejs10.x
      AutoPublishAlias: live
      Description: 'Lambda function for CD Demo'
      MemorySize: 128
      Timeout: 30
      DeploymentPreference:
          Type: Linear10PercentEvery1Minute
          Alarms:
            - !Ref AliasErrorMetricGreaterThanZeroAlarm
            - !Ref LatestVersionErrorMetricGreaterThanZeroAlarm
          Hooks:
            PreTraffic: !Ref PreTrafficHook
            PostTraffic: !Ref PostTrafficHook
      Events:
        HelloWorldAPI:
          Type: Api
          Properties:
            Path: /
            Method: get
      Environment:
        Variables:
          REGION: us-west-1
          
  AliasErrorMetricGreaterThanZeroAlarm:
    Type: "AWS::CloudWatch::Alarm"
    Properties:
      AlarmDescription: Lambda Function Error > 0
      ComparisonOperator: GreaterThanThreshold
      Dimensions:
        - Name: Resource
          Value: !Sub "${HelloWorld}:live"
        - Name: FunctionName
          Value: !Ref HelloWorld
      EvaluationPeriods: 2
      MetricName: Errors
      Namespace: AWS/Lambda
      Period: 60
      Statistic: Sum
      Threshold: 0

  LatestVersionErrorMetricGreaterThanZeroAlarm:
    Type: "AWS::CloudWatch::Alarm"
    Properties:
      AlarmDescription: Lambda Function Error > 0
      ComparisonOperator: GreaterThanThreshold
      Dimensions:
        - Name: Resource
          Value: !Sub "${HelloWorld}:live"
        - Name: FunctionName
          Value: !Ref HelloWorld
        - Name: ExecutedVersion
          Value: !GetAtt HelloWorld.Version.Version
      EvaluationPeriods: 2
      MetricName: Errors
      Namespace: AWS/Lambda
      Period: 60
      Statistic: Sum
      Threshold: 0


  PreTrafficHook:
    Type: AWS::Serverless::Function
    Properties:
      Handler: preTrafficHook.handler
      Runtime: nodejs10.x
      CodeUri: ./Lambda
      FunctionName: 'CodeDeployHook_PreTrafficHook'
      Policies:
        - Version: "2012-10-17"
          Statement: 
          - Effect: "Allow"
            Action: 
              - "codedeploy:PutLifecycleEventHookExecutionStatus"
            Resource:
              !Sub 'arn:aws:codedeploy:${AWS::Region}:${AWS::AccountId}:deploymentgroup:${ServerlessDeploymentApplication}/*'
        - Version: "2012-10-17"
          Statement: 
          - Effect: "Allow"
            Action: 
              - "lambda:InvokeFunction"
            Resource: !Ref HelloWorld.Version
      DeploymentPreference:
        Enabled: false
      Timeout: 5
      Environment:
        Variables:
          NewVersion: !Ref HelloWorld.Version

  PostTrafficHook:
    Type: AWS::Serverless::Function
    Properties:
      Handler: postTrafficHook.handler
      Runtime: nodejs10.x
      CodeUri: ./Lambda
      FunctionName: 'CodeDeployHook_PostTrafficHook'
      Policies:
        - Version: "2012-10-17"
          Statement: 
          - Effect: "Allow"
            Action: 
              - "codedeploy:PutLifecycleEventHookExecutionStatus"
            Resource:
              !Sub 'arn:aws:codedeploy:${AWS::Region}:${AWS::AccountId}:deploymentgroup:${ServerlessDeploymentApplication}/*'
        - Version: "2012-10-17"
          Statement: 
          - Effect: "Allow"
            Action: 
              - "lambda:InvokeFunction"
            Resource: !Ref HelloWorld.Version
      DeploymentPreference:
        Enabled: false
      Timeout: 5
      Environment:
        Variables:
          NewVersion: !Ref HelloWorld.Version