AWS CodeDeploy - Lambda pre-traffic hook (YAML)

template.yml

AWSTemplateFormatVersion : '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Resources:
  myFunctionToBeDeployed:
    Type: AWS::Serverless::Function
    Properties:
      Handler: index.handler
      AutoPublishAlias: live
      DeploymentPreference:
          Type: Linear10PercentEvery1Minute
          Hooks:
            PreTraffic: !Ref preTrafficHook
      # ... 
      # all the other properties here
      # ... 

  preTrafficHook:
    Type: AWS::Serverless::Function
    Properties:
      Handler: preTrafficHook.handler
      Runtime: nodejs8.10
      DeploymentPreference:
        Enabled: false
      Environment:
        Variables:
          NewVersion: !Ref myFunctionToBeDeployed.Version
      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 myFunctionToBeDeployed.Version