[cfn-lint] WS1004 incorrectly reported

[shawnbucholtz]

What were you trying to accomplish?

Resolve warnings. See aws-cloudformation/cfn-lint#3103

cfn-lint incorrectly reports:

[cfn-lint] WS1004: Lambda function xxx does not have a corresponding log group with a Retention property

Expected Behavior

When there is an explicit !Ref to a defined log group with the RetentionInDays property set then WS1004 should not be flagged, unless I am misunderstanding the warning.

Current Behavior

Warning about WS1004 despite having a log group with a retention property referenced.

Possible Solution

Manual solution is adding .cfnlintrc.yaml to ignore the warning.

Steps to Reproduce (for bugs)

Run cfn-lint with the serverless template below:

AWSTemplateFormatVersion: "2010-09-09"
Transform: AWS::Serverless-2016-10-31

Resources:

  LambdaProxyFunction:
    Type: AWS::Serverless::Function
    Properties:
      CodeUri: src/
      FunctionName: MyFunction
      Handler: index.handler
      LoggingConfig:
        LogFormat: JSON
        LogGroup: !Ref LambdaProxyLogGroup
      MemorySize: 512
      PackageType: Zip
      ReservedConcurrentExecutions: 1
      Runtime: nodejs18.x
      Timeout: 10
      Tracing: Active

  LambdaProxyLogGroup:
    DeletionPolicy: Retain
    UpdateReplacePolicy: Retain
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupClass: STANDARD
      RetentionInDays: 180

Environment

Python 3.8.10
cfn-lint 0.86.0
cfn-lint-serverless 0.3.2

Log to large to paste, attached instead.

out.log

[michael-k]

The warning was valid until November 2023, see this announcement: https://aws.amazon.com/about-aws/whats-new/2023/11/aws-lambda-controls-search-filter-aggregate-lambda-function-logs/