Deploying S3 bucket with SNS notification event not possible

[ffxsam]

This is a Bug Report

Description

For bug reports:

• What went wrong?

It's not possible to deploy a stack with an S3 bucket that has an SNS topic as an event notification. Is something missing in the CloudFormation file generated by Serverless? According to this AWS support article, it seems an AWS::SNS::TopicPolicy is needed, and this is not generated by Serverless:
https://aws.amazon.com/premiumsupport/knowledge-center/unable-validate-destination-s3/

• What did you expect should have happened?

The stack should deploy without errors.

• What was the config you used?

See bottom for serverless.yml file.

• What stacktrace or error message from your provider did you see?

Additional Data

• Serverless Framework Version you're using: 1.26.1
• Operating System: macOS 10.13.3
• Stack Trace:
• Provider Error messages:

  Serverless Error ---------------------------------------

  An error occurred: TestBucket - Unable to validate the following destination configurations.

serverless.yaml:

service:
  name: TestStack

# Add the serverless-webpack plugin
plugins:
  - serverless-webpack

provider:
  name: aws
  runtime: nodejs6.10
  variableSyntax: '\$\(([\s\S]+?)\)'

custom:
  stage: $(opt:stage, self:provider.stage)
  topicName: kerpow
  topic: $(self:service)-$(self:custom.topicName)-$(self:custom.stage)
  topicArn:
    Fn::Sub: arn:aws:sns:$(self:provider.region):${AWS::AccountId}:$(self:custom.topic)

functions:
  first:
    handler: first.hello
    events:
      - sns: $(self:custom.topic)

resources:
  Resources:
    TestBucket:
      Type: AWS::S3::Bucket
      DependsOn: SNSTopic$(self:service)$(self:custom.topicName)$(self:custom.stage)
      Properties:
        BucketName: aa-test-95872017
        NotificationConfiguration:
          TopicConfigurations:
            - Event: s3:ObjectCreated:Put
              Filter:
                S3Key:
                  Rules:
                    - Name: prefix
                      Value: staging/
              Topic: $(self:custom.topicArn)

[ffxsam]

This template works. It's a bit messier than I'd like. IMO Serverless should handle this automatically.

service:
  name: TestStack

# Add the serverless-webpack plugin
plugins:
  - serverless-webpack

provider:
  name: aws
  runtime: nodejs6.10
  variableSyntax: '\$\(([\s\S]+?)\)'

custom:
  stage: $(opt:stage, self:provider.stage)
  topicName: kerpow
  topic: $(self:service)-$(self:custom.topicName)-$(self:custom.stage)
  topicArn:
    Fn::Sub: arn:aws:sns:$(self:provider.region):${AWS::AccountId}:$(self:custom.topic)

functions:
  first:
    handler: first.hello
    events:
      - sns: $(self:custom.topic)

resources:
  Resources:
    TestBucket:
      Type: AWS::S3::Bucket
      DependsOn: SNSTopicPolicy
      Properties:
        BucketName: aa-test-95872017
        NotificationConfiguration:
          TopicConfigurations:
            - Event: s3:ObjectCreated:Put
              Filter:
                S3Key:
                  Rules:
                    - Name: prefix
                      Value: staging/
              Topic: $(self:custom.topicArn)
    SNSTopicPolicy:
      Type: AWS::SNS::TopicPolicy
      Properties:
        PolicyDocument:
          Version: "2012-10-17"
          Statement:
            - Effect: Allow
              Principal:
                AWS: "*"
              Action: sns:Publish
              Resource: $(self:custom.topicArn)
              Condition:
                ArnLike:
                  aws:SourceArn: arn:aws:s3:::aa-test-95872017
        Topics:
          - Ref: SNSTopic$(self:service)$(self:custom.topicName)$(self:custom.stage)

[ffxsam]

@HyperBrain @dschep Just following up on an old issue that's probably still existent.

[hdryx]

Hi,
I'm trying this code but i'm getting this error :
The CloudFormation template is invalid: Template format error: Unresolved resource dependencies [SNSTopic$(self:service)$(self:custom.topicName)$(self:custom.stage)] in the Resources block of the template

How to solve that ?

[technicallyfeasible]

@hdryx you will get this error if any of your variables contain "-" characters. Serverless generates the final topic name out of the original name while removing "-".

So if your topic is called "normalize-lambda-dev-raw-ingest" then the Ref would be "SNSTopicNormalizelambda${self:custom.stage}rawingest".

Hope that helps

[RuiLoureiro]

What is the state of this? Is the solution provided by @ffxsam still the best option?