False-positive configuration changes for layers and logging in Lambda deployments

[konsloiz]

Description:
When deploying Lambda functions using the aws-lambda-deploy GitHub Action, the action sometimes reports configuration changes that are not actually being made. This mainly affects layers and logging configuration.

Observed behavior:
• The action detects changes for CodeSize of layers and log configuration fields (LogFormat, ApplicationLogLevel, SystemLogLevel).
• These fields are either read-only or provide more detail than what can be configured through the action.
• As a result, the action reports “changes” even though the actual configuration remains the same.

Example Lambda configuration used in workflow:

"ecr-cleanup-function": {
  "function_name": "ecr-cleanup-function",
  "code_artifacts_dir": "modules/ecr-cleanup/files",
  "handler": "ecr_cleanup_detection_function.lambda_handler",
  "timeout": "900",
  "memory_size": "1024",
  "runtime": "python3.12",
  "layers": [
    "arn:aws:lambda:eu-central-1:xxxxxxxxxxxxxx:layer:aws-cli:4",
    "arn:aws:lambda:eu-central-1:xxxxxxxxxxxxxx:layer:kubernetes_pyyaml:3"
  ],
  "function_description": "Create a json file containing images scheduled for deletion",
  "logging_config": "{\"LogFormat\":\"JSON\"}"
}

Debug output from Lambda:

Layers from config: [
  {
    "Arn": "arn:aws:lambda:eu-central-1:xxxxxxxxxxxxxx:layer:aws-cli:4",
    "CodeSize": 25659747
  },
  {
    "Arn": "arn:aws:lambda:eu-central-1:xxxxxxxxxxxxxx:layer:kubernetes_pyyaml:3",
    "CodeSize": 9231481
  }
]
{
  "LogFormat": "JSON",
  "ApplicationLogLevel": "INFO",
  "SystemLogLevel": "INFO",
  "LogGroup": "/aws/lambda/ecr-cleanup-function"
}

Issue:
• The action cannot pass fields like CodeSize or the detailed logging fields.
• Therefore, it incorrectly detects changes that do not exist, creating misleading deployment results. (see logs bellow)

Getting current configuration for function ecr-cleanup-function
Configuration difference detected in Layers
Configuration difference detected in LoggingConfig

Expected behavior:
• The action should ignore read-only or derived fields such as CodeSize and logging detail fields that aren’t configurable.

Request:
• Please consider ignoring read-only/derived fields when detecting configuration changes to avoid false-positive updates.