template.yaml

AWSTemplateFormatVersion : '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Description: An example SAM template for Lambda Safe Deployments.

Resources:

  returnS3Buckets:
    Type: AWS::Serverless::Function
    Properties:
      Handler: returnS3Buckets.handler
      Runtime: nodejs6.10
      AutoPublishAlias: live
      Policies:
        - Version: "2012-10-17"
          Statement: 
          - Effect: "Allow"
            Action: 
              - "s3:ListAllMyBuckets"
            Resource: '*'
      DeploymentPreference:
          Type: Linear10PercentEvery1Minute
          Hooks:
            PreTraffic: !Ref preTrafficHook
      Events:
        Api:
          Type: Api
          Properties:
            Path: /test
            Method: get

  preTrafficHook:
    Type: AWS::Serverless::Function
    Properties:
      Handler: preTrafficHook.handler
      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 returnS3Buckets.Version
      Runtime: nodejs6.10
      FunctionName: 'CodeDeployHook_preTrafficHook'
      DeploymentPreference:
        Enabled: false
      Timeout: 5
      Environment:
        Variables:
          NewVersion: !Ref returnS3Buckets.Version