AWS CloudFormation setting SNS trigger to Lambda - aws-lambda

Question

I want to add SNS as a trigger for Lambda in CloudFormation template but I it is not working for me. Below is the code I applied and I get lambda, sns and lambda subscription to SNS but I can't add trigger to lambda. Does anyone have any idea how to do it?
LambdaRole:
Type: 'AWS::IAM::Role'
Properties:
AssumeRolePolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Principal:
Service:
- lambda.amazonaws.com
Action:
- 'sts:AssumeRole'
Path: /
Policies:
- PolicyName: lambda_policy
PolicyDocument:
Version: "2012-10-17"
Statement:
- Effect: Allow
Action: '*'
Resource: '*'
Lambdafunction:
Type: AWS::Lambda::Function
Properties:
Handler: index.handler
Role: !GetAtt LambdaRole.Arn
# Role: !GettAtt [LambdaRole, Arn]
Code:
S3Bucket: lambda-s3
S3Key: lambda.zip
Runtime: python3.9
Timeout: 30
PermissionSNStoLambda:
Type: 'AWS::Lambda::Permission'
Properties:
Action: 'lambda:InvokeFunction'
FunctionName: !Ref Lambdafunction
Principal: sns.amazonaws.com
test2Topic:
Type: 'AWS::SNS::Topic'
Properties:
DisplayName: Scale of Test Web group
Subscription:
- Protocol: lambda
Endpoint: !GetAtt Lambdafunction.Arn
SNSPolicy:
Type: 'AWS::SNS::TopicPolicy'
Properties:
Topics:
- !Ref test2Topic
PolicyDocument:
Version: '2012-10-17'
Statement:
- Effect: Allow
Principal: AWS: '*'
Action:
- 'SNS:GetTopicAttributes'
- 'SNS:SetTopicAttributes'
- 'SNS:AddPermission'
- 'SNS:RemovePermission'
- 'SNS:DeleteTopic'
- 'SNS:Subscribe'
- 'SNS:ListSubscriptionsByTopic'
- 'SNS:Publish'
- 'SNS:Receive'
Resource: !Ref test2Topic
This is the most logical for me to use to add the trigger, but no success:
SNSTriggersLambda:
Type: AWS::Lambda::EventInvokeConfig
Properties:
DestinationConfig:
OnFailure:
Destination: !Ref test2Topic
OnSuccess:
Destination: !Ref test2Topic
FunctionName: !Ref Lambdafunction
MaximumEventAgeInSeconds: 70
MaximumRetryAttempts: 1
Qualifier: $LATEST

Answer 1

I just managed to resolve the issue. I needed one extra line in permission section stating source ARN for SNS Topic:
PermissionSNStoLambda:
Type: 'AWS::Lambda::Permission'
Properties:
Action: 'lambda:InvokeFunction'
FunctionName: !Ref Lambdafunction
Principal: sns.amazonaws.com
SourceArn: !Ref test2Topic
It works now!