How do I create a subscription between my Amazon SQS queue and an Amazon SNS topic in CloudFormation?

Resolution

Choose one of the following solutions based on your use case:

• You have an SNS topic and SQS queue in the same stack. To resolve, use a CloudFormation template to create a topic that sends messages to SQS queues.
• Your SNS topic is in one stack and the SQS queue that will subscribe to that topic is in another stack. Both stacks are in the same AWS Region. To resolve, create a cross-stack reference.
  Note: When you create a cross-stack reference, export the Amazon Resource Name (ARN) of the SQS queue in one stack. Then, import that SQS queue ARN in the subscription endpoint property of the SNS topic in the other stack.
• Your SNS topic and SQS queue are in separate Regions. To resolve, follow the steps in the Use the AWS::SNS::Subscription resource to set up a cross-Region subscription section.
• Your SNS topic and SQS queue are in separate AWS accounts. To resolve, follow the steps in the Use the AWS::SNS::Subscription resource to set up a cross-account subscription section.

Use the AWS::SNS::Subscription resource to set up a cross-Region subscription

1.    In the CloudFormation template for the stack in one AWS Region, declare the SNS topic in that Region. Then, create an output resource to annotate the SNS topic ARN.

See the following JSON and YAML example templates.

JSON:

{
 "Resources": {
  "SnsTopic": {
   "Type": "AWS::SNS::Topic"
  }
 },
 "Outputs": {
  "SnsTopicArn": {
   "Value": {
     "Ref": "SnsTopic"
   }
  }
 }
}

YAML:

Resources:
  SnsTopic:
    Type: AWS::SNS::Topic
Outputs:
  SnsTopicArn:
    Value: !Ref SnsTopic

2.    In a CloudFormation template for the other stack in the other Region, define the AWS::SNS::Subscription resource and the SQS queue.

Note: In Parameters, replace awsSNSTopicArnExample with your SNS topic ARN. Replace us-east-1 with the Region of the stack from step 1.

See the following JSON and YAML example templates.

JSON:

{
 "Parameters": {
  "SNSTopicARN": {
   "Type": "String",
   "Default": "awsSNSTopicArnExample"
  },
  "TopicRegion": {
   "Type": "String",
   "Default": "us-east-1"
  }
 },
 "Resources": {
  "Queue": {
   "Type": "AWS::SQS::Queue"
  },
  "SnsSubscription": {
   "Type": "AWS::SNS::Subscription",
   "Properties": {
    "Protocol": "sqs",
    "Endpoint": {
     "Fn::GetAtt": [
      "Queue",
      "Arn"
     ]
    },
    "Region": {
     "Ref": "TopicRegion"
    },
    "TopicArn": {
     "Ref": "SNSTopicARN"
    }
   }
  }
 }
}

YAML:

Parameters:
  SNSTopicARN:
    Type: String
    Default: awsSNSTopicArnExample 
  TopicRegion:
    Type: String
    Default: us-east-1

Resources:
  Queue:
    Type: AWS::SQS::Queue

  SnsSubscription:
    Type: AWS::SNS::Subscription
    Properties:
      Protocol: sqs
      Endpoint: !GetAtt Queue.Arn
      Region: !Ref TopicRegion
      TopicArn: !Ref SNSTopicARN

Your cross-Region subscription is now set up.

Use the AWS::SNS::Subscription resource to set up a cross-account subscription

1.    In the CloudFormation template for the stack in one AWS source account, declare the SNS topic and AWS::SNS::TopicPolicy. Then, create an output resource to annotate the SNS topic ARN and provide your destination AWS account as a parameter.

See the following JSON and YAML example templates.

JSON:

{
  "Parameters": {
    "CrossAccountNumber": {
      "AllowedPattern": "[0-9]+",
      "Description": "The 12 digit AWS account number to grant access to.",
      "MaxLength": "12",
      "MinLength": "12",
      "Type": "String",
      "Default": 123456789101
    }
  },
  "Resources": {
    "SnsTopic": {
      "Type": "AWS::SNS::Topic"
    },
    "SnsTopicPolicy": {
      "Type": "AWS::SNS::TopicPolicy",
      "DependsOn": "SnsTopic",
      "Properties": {
        "PolicyDocument": {
          "Version": "2012-10-17",
          "Statement": [
            {
              "Sid": "SnsTopicPolicy",
              "Effect": "Allow",
              "Principal": {
                "AWS": {
                  "Fn::Sub": "arn:aws:iam::${CrossAccountNumber}:root"
                }
              },
              "Action": [
                "sns:Subscribe"
              ],
              "Resource": {
                "Ref": "SnsTopic"
              }
            }
          ]
        },
        "Topics": [
          {
            "Ref": "SnsTopic"
          }
        ]
      }
    }
  },
  "Outputs": {
    "SnsTopicArn": {
      "Value": {
        "Ref": "SnsTopic"
      }
    }
  }
}

YAML:

Parameters:
 CrossAccountNumber:
  AllowedPattern: '[0-9]+'
  Description: The 12 digit AWS account number to grant access to.
  MaxLength: '12'
  MinLength: '12'
  Type: String
  Default: 123456789101
Resources:
 SnsTopic:
  Type: AWS::SNS::Topic
 SnsTopicPolicy:
  Type: AWS::SNS::TopicPolicy
  DependsOn: SnsTopic
  Properties:
   PolicyDocument:
    Version: '2012-10-17'
    Statement:
    - Sid: SnsTopicPolicy
      Effect: Allow
      Principal:
       AWS: !Sub arn:aws:iam::${CrossAccountNumber}:root
      Action:
       - sns:Subscribe
      Resource: !Ref SnsTopic
   Topics:
    - !Ref SnsTopic
Outputs:
 SnsTopicArn:
  Value: !Ref SnsTopic

2.    In the CloudFormation template for the stack in the AWS account where you want to extend your subscription, define the AWS::SNS::Subscription resource. Also, define the SQS queue and AWS::SQS::QueuePolicy policy.

Note: In Parameters, replace awsSNSTopicArn with your SNS topic ARN. Replace us-east-1 with the Region of the stack from step 1.

See the following JSON and YAML example templates.

JSON:

{
 "Parameters": {
  "SNSTopicARN": {
   "Type": "String",
   "Default": "awsSNSTopicArn"
  },
  "TopicRegion": {
   "Type": "String",
   "Default": "us-east-1"
  }
 },
 "Resources": {
  "Queue": {
   "Type": "AWS::SQS::Queue"
  },
  "SqsQueuePolicy": {
   "Type": "AWS::SQS::QueuePolicy",
   "Properties": {
    "PolicyDocument": {
     "Version": "2012-10-17",
     "Id": "MyQueuePolicy",
     "Statement": [
      {
       "Sid": "Allow-SNS-SendMessage",
       "Effect": "Allow",
       "Principal": "*",
       "Action": [
        "sqs:SendMessage"
       ],
       "Resource": {
        "Fn::GetAtt": [
         "Queue",
         "Arn"
        ]
       },
       "Condition": {
        "ArnEquals": {
         "aws:SourceArn": {
          "Ref": "SNSTopicARN"
         }
        }
       }
      }
     ]
    },
    "Queues" : [
     {
      "Ref" : "Queue"
     }
    ]
   }
  },
  "SnsSubscription": {
   "Type": "AWS::SNS::Subscription",
   "Properties": {
    "Protocol": "sqs",
    "Endpoint": {
     "Fn::GetAtt": [
      "Queue",
      "Arn"
     ]
    },
    "Region": {
     "Ref": "TopicRegion"
    },
    "TopicArn": {
     "Ref": "SNSTopicARN"
    }
   }
  }
 }
}

YAML:

Parameters:
 SNSTopicARN:
  Type: String
  Default: awsSNSTopicArn
 TopicRegion:
  Type: String
  Default: us-east-1
Resources:
 Queue:
  Type: AWS::SQS::Queue
 SqsQueuePolicy:
  Type: AWS::SQS::QueuePolicy
  Properties:
   PolicyDocument:
    Version: '2012-10-17'
    Id: MyQueuePolicy
    Statement:
    - Sid: Allow-SNS-SendMessage
      Effect: Allow
      Principal: "*"
      Action:
      - sqs:SendMessage
      Resource: !GetAtt Queue.Arn
      Condition:
       ArnEquals:
        aws:SourceArn: !Ref SNSTopicARN
   Queues:
    - !Ref Queue
 SnsSubscription:
  Type: AWS::SNS::Subscription
  Properties:
   Protocol: sqs
   Endpoint: !GetAtt Queue.Arn
   Region: !Ref TopicRegion
   TopicArn: !Ref SNSTopicARN