canary-deployment.yaml

AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: >
  This template creates the lambda functions, Step Functions, and CloudWatch Events Streams 
  required to trigger and execute the switch from one ECS service to another. It also creates
  the blue ECS service - so upon completion the trigger should fire and the canary switch should start.
  
Parameters:
  SetupStackName:
    Type: String
    Default: "canary-setup"
  TemplateBucket:
    Type: String
    Default: "nbrand-code"

Resources:
  handleECSEvents:
    Type: 'AWS::Serverless::Function'
    DependsOn: StepFunction
    Properties:
      Handler: index.lambda_handler
      Runtime: python2.7
      CodeUri: # CodeUri: 's3://my-code-bucket/my-function.zip'
        Bucket: #!Ref TemplateBucket
          Fn::ImportValue:
            !Sub "${SetupStackName}-Bucket"
        Key: lambdafunctions/handleECSEvents.zip
      Description: Handles ECS Events even if there are duplicates or timing issues
      Environment:
        Variables:
          TRIGGER_CONTAINERS: 'green-app'
          STEP_FUNCTION: !GetAtt StepFunction.Outputs.StepArn
      MemorySize: 128
      Timeout: 3
      Policies:
        - "AWSLambdaFullAccess"
        - "AWSStepFunctionsFullAccess"
      Events:
        ECSStream:
          Description: "Sending ECS events to a Lambda function for processing"
          Type: CloudWatchEvent
          Properties:
            Pattern:
              source: 
                - 'aws.ecs'
              detail-type: 
                - 'ECS Task State Change'
              detail:
                lastStatus: 
                  - 'RUNNING'
                desiredStatus: 
                  - 'RUNNING'

  Service:
    Type: AWS::CloudFormation::Stack
    DependsOn: handleECSEvents          # Make sure that lambda function is ready
    DependsOn: handleECSEventsECSStream # Make sure that the Event Stream is ready first
    Properties:
      TemplateURL: !Sub https://s3.amazonaws.com/${TemplateBucket}/templates/greenService.yaml
      Parameters:
        Cluster: 
          Fn::ImportValue: 
            !Sub "${SetupStackName}-Cluster" #!GetAtt Cluster.Outputs.ClusterName
        TargetGroup: 
          Fn::ImportValue:
            !Sub "${SetupStackName}-TG"      #!GetAtt LoadBalancer.Outputs.TargetGroup
            
  StepFunction:
    Type: AWS::CloudFormation::Stack
    Properties:
      TemplateURL: !Sub https://s3.amazonaws.com/${TemplateBucket}/templates/stepfunction.yaml
      Parameters:
        TemplateBucket: 
          Fn::ImportValue: 
            !Sub "${SetupStackName}-Bucket"