CloudFormation Custom Resource Experiments

no_physical_resource_id.yml

---
AWSTemplateFormatVersion: 2010-09-09
Parameters:
  Param:
    Type: String
    Default: v1
Resources:
  MyCustomResource:
    Type: Custom::MyResouce
    Properties:
      ServiceToken: !Sub |-
        ${MyLambdaFunction.Arn}
      Param: !Sub |-
        ${Param}
  MyLambdaFunction:
    Type: AWS::Lambda::Function
    Properties:
      Code:
        ZipFile: >
          var response = require('cfn-response');
          exports.handler = function(event, context) {
            response.send(event, context, response.SUCCESS, {});
          };
      Handler: index.handler
      Role: !Sub |-
        ${MyRole.Arn}
      Runtime: nodejs4.3
  MyRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: CloudWatchLogs
          PolicyDocument:
            Statement:
              - Action:
                - logs:CreateLogGroup
                - logs:CreateLogStream
                - logs:PutLogEvents
                Effect: Allow
                Resource: arn:aws:logs:*:*:*

specify_physical_resource_id.yml

---
AWSTemplateFormatVersion: 2010-09-09
Parameters:
  Param:
    Type: String
    Default: v1
Resources:
  MyCustomResource:
    Type: Custom::MyResouce
    Properties:
      ServiceToken: !Sub |-
        ${MyLambdaFunction.Arn}
      Param: !Sub |-
        ${Param}
  MyLambdaFunction:
    Type: AWS::Lambda::Function
    Properties:
      Code:
        ZipFile: >
          var response = require('cfn-response');
          exports.handler = function(event, context) {
            response.send(event, context, response.SUCCESS, {}, 'PhysicalResourceID');
          };
      Handler: index.handler
      Role: !Sub |-
        ${MyRole.Arn}
      Runtime: nodejs4.3
  MyRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: CloudWatchLogs
          PolicyDocument:
            Statement:
              - Action:
                - logs:CreateLogGroup
                - logs:CreateLogStream
                - logs:PutLogEvents
                Effect: Allow
                Resource: arn:aws:logs:*:*:*