AWSTemplateFormatVersion: 2010-09-09
Description: A SQL only IoT republish rule that sends Hello, World messages from the Greengrass group to a shared topic

Parameters:
  AWSIOTTHINGNAME:
    Type: String

  GROUPID:
    Type: String

  AWSIOTTHINGARN:
    Type: String

  AWSGREENGRASSGROUPNAME:
    Type: String

Resources:
  HelloWorldRepublishTopicRule:
    Type: AWS::IoT::TopicRule
    Properties:
      RuleName: !Join [ "", [ !Ref "AWSIOTTHINGNAME", "_HelloWorldRepublishRule" ] ]
      TopicRulePayload:
        RuleDisabled: false
        Sql: !Join [ "", [ "SELECT 'Hello World received from ", !Ref "AWSGREENGRASSGROUPNAME", "' AS message FROM '", !Ref "AWSIOTTHINGNAME", "/python/hello/world'" ] ]
        Actions:
          - Republish:
              Topic: !Join [ "/", [ "hello", "world" ] ]
              RoleArn: !GetAtt HelloWorldRepublishRole.Arn
  HelloWorldRepublishRole:
    Type: AWS::IAM::Role
    Properties:
      RoleName: !Join [ "", [ !Ref "AWSIOTTHINGNAME", "_HelloWorldRepublishRole" ] ]
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Action:
              - sts:AssumeRole
            Principal:
              Service:
                - iot.amazonaws.com
      Policies:
        - PolicyName: root
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action: iot:Publish
                Resource: !Join [ "", [ "arn:aws:iot:", !Ref "AWS::Region", ":", !Ref "AWS::AccountId", ":topic/hello/world" ] ]