ARN as a parameter in Cloud Formation Stack - amazon-web-services

Question

I wanted to use the ARN as parameter input to cloudformation stack resources EventRuleRegion1 - Target as well as EventBridgeIAMrole , but it is not working. when i call with Ref function
Original ARN
arn:aws:events:ap-southeast-2:123456789123:event-bus/central-eventbus-sydney
When i give the arn directly in code its working fine.
Code
AWSTemplateFormatVersion: 2010-09-09
Parameters:
EventBridgeName:
Description: Enter the Event Bridge Name
Type: String
Default: ec2-lifecycle-events
EventBusName:
Description: Enter the Central Event Bus Name
Type: String
Default: central-eventbus-sydney
EventBusArn:
Description: Enter the ARN of Central Event Bus
Type: String
Default: arn:aws:events:ap-southeast-2:123456789123:event-bus/central-eventbus-sydney
Monitoringaccount:
Description: Enter the Monitoring AWS account number
Type: String
Default: 123456789123
Resources:
EventRuleRegion1:
Type: AWS::Events::Rule
Properties:
Description: Event rule to send events to monitoring account event bus
EventBusName: default
EventPattern:
source:
- aws.ec2
detail-type:
- "EC2 Instance State-change Notification"
detail:
state:
- "running"
- "stopped"
- "terminated"
Name: !Ref EventBridgeName
State: ENABLED
Targets:
- Arn: >-
- !Join [ "", [ !Sub "arn:aws:events:${AWS::Region}:123456789123:event-bus/",!Ref EventBusName ] ]
Id: !Ref EventBusName
RoleArn: !GetAtt
- EventBridgeIAMrole
- Arn
EventBridgeIAMrole:
Type: 'AWS::IAM::Role'
Properties:
AssumeRolePolicyDocument:
Version: 2012-10-17
Statement:
- Effect: Allow
Principal:
Service: !Sub events.amazonaws.com
Action: 'sts:AssumeRole'
Path: /
Policies:
- PolicyName: PutEventsDestinationBus
PolicyDocument:
Version: 2012-10-17
Statement:
- Effect: Allow
Action:
- 'events:PutEvents'
Resource:
- >-
- !Join [ "", [ !Sub "arn:aws:events:${AWS::Region}:123456789123:event-bus/",!Ref EventBusName ] ]
Error
Parameter - !Join [ "", [ !Sub "arn:aws:events:${AWS::Region}:123456789123:event-bus/",!Ref EventBusName ] ] is not valid. Reason: Provided Arn is not in correct format. (Service: AmazonCloudWatchEvents; Status Code: 400; Error Code: ValidationException; Request ID: 0d52a1d6-095e-44f7-9455-b7481dc4fb8d; Proxy: null)

Answer 1

The use of >- will result in literal strings, not evaluation of your CFN functions (join, ref). It should be:
Targets:
- Arn: !Join [ "", [ !Sub "arn:aws:events:${AWS::Region}:123456789123:event-bus/",!Ref EventBusName ] ]