TypeError: event.cloudwatchLog.logGroup.replace is not a function

This is a (Bug Report Proposal)

Description

For bug reports:

• What went wrong?

Get the error when reference a log group.

TypeError: event.cloudwatchLog.logGroup.replace is not a function

• What did you expect should have happened?

replace the reference log group name with real one.

• What was the config you used?

functions:
  pushCustomAccesslogs:
    handler: logs/logs.handler
    events:
      - cloudwatchLog:
          logGroup: { "Ref": "CustomAccessLogs" }

resources:
  Resources:
    CustomAccessLogs:
      Type: AWS::Logs::LogGroup

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

Serverless: Invoke aws:common:cleanupTempDir
Serverless: Packaging service...
Serverless: Excluding development dependencies...
LogGroupName:  { Ref: 'CustomAccessLogs' }      # <=== Here is the name

  Type Error ---------------------------------------------

  event.cloudwatchLog.logGroup.replace is not a function

     For debugging logs, run again after setting the "SLS_DEBUG=*" environment variable.

  Stack Trace --------------------------------------------

TypeError: event.cloudwatchLog.logGroup.replace is not a function
    at functionObj.events.forEach.event (/usr/lib/node_modules/serverless/lib/plugins/aws/package/compile/events/cloudWatchLog/index.js:48:59)

The error line is:

           LogGroupName = event.cloudwatchLog.logGroup.replace(/\r?\n/g, '');

https://github.com/serverless/serverless/blob/c345e9a9bfb5dd49a13788009430e24c400243f2/lib/plugins/aws/package/compile/events/cloudWatchLog/index.js#L48

Additional Data

Your Environment Information ----------------------------- OS: linux Node Version: 6.11.3 Serverless Version: 1.25.0

I added a debug line before replace function:

          console.log("LogGroupName: " , event.cloudwatchLog.logGroup);

from deploy debug log, seems the logGroup name is not referenced properly:

LogGroupName:  { Ref: 'CustomAccessLogs' }

[medikoo]

I’m closing as it’s not really a bug. It’s just we do not support CF intrinsic functions at logGroup property, as to properly handle the event we need to have log group name resolved.

This issue was kept open initially as we didn’t have proper error reporting in place, but now that’s solved with configuration validation backed by schema, and schema clearly indicates we accept an only plain string as an input.

If you feel we can maintain the same functionality while extending the support for CF intrinsic functions at logGroup property, please open a new feature request, detailing the idea. If it’ll promise desired results we will definitely welcome the PR.

[ghost]

Running in this issue too, whereby we are deploying into multiple accounts and want to dynamically replace the region and account

read-cloudwatch:
  handler: build/read-cloudwatch.handler
  timeout: 30
  events:
      - cloudwatchLog:  
        - Fn::Sub:
          - sns/${AWS::Region}/${AWS::AccountId}/DirectPublishToPhoneNumber