Suppress unnecessary error log for ERROR_NOT_SUPPORTED cases

[bobsira]

This pull request improves error handling in the LogFileMonitor component by suppressing unnecessary error logs for benign ERROR_NOT_SUPPORTED cases. This helps prevent log pollution and ensures only actionable errors are logged.

Error handling improvements:

• Added a conditional check in LogFileMonitor::InitializeDirectoryChangeEventsQueue() to suppress logging for ERROR_NOT_SUPPORTED, reducing unnecessary log entries for benign errors.
• Updated LogFileMonitor::LogFileAddEventHandler() to only log errors when the status is not ERROR_NOT_SUPPORTED, further preventing log pollution.

Logging clarity:

• Ensured that only actionable errors are logged by guarding error trace calls with the new conditional check in both affected methods. [1] [2]Previously, the parser advanced the buffer pointer one character too far after parsing a number, causing it to skip important JSON structural characters (such as commas or closing braces). This led to errors when parsing numbers that were not the last member in an object. The fix ensures the parser leaves the terminating character in place, allowing correct parsing of all numeric values regardless of their position in the

[Copilot]

Pull Request Overview

This PR fixes a JSON parser bug where numeric values caused parsing failures when they weren't the last element in an object. The fix corrects buffer pointer advancement to avoid skipping structural characters after numbers.

• Removed incorrect buffer pointer advancement after parsing numbers to preserve terminating characters
• Added error handling improvements to suppress benign ERROR_NOT_SUPPORTED logging
• Updated code comments to clarify the numeric parsing behavior

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
JsonFileParser.cpp	Fixed buffer pointer advancement logic and updated comments for numeric value parsing
LogFileMonitor.cpp	Added conditional check to suppress logging of benign ERROR_NOT_SUPPORTED errors

[mloskot]

@bobsira I think similar workaround is needed here

windows-container-tools/LogMonitor/src/LogMonitor/LogFileMonitor.cpp

Lines 1082 to 1088 in 09983f6

	logWriter.TraceError(
	Utility::FormatString(
	L"Error in log file monitor. Failed to query file ID. File: %ws. Error: %d",
	fullLongPath.c_str(),
	status
	).c_str()
	);

I'm testing your LogMonitor.exe build you linked in #214 (comment) and

The waitInSeconds: 10 does not seem to help delay the files query in this particular case.

My LogMonitorConfig.json is this

{
  "LogConfig": {
    "sources": [
      {
        "includeSubdirectories": false,
        "filter": "*.log",
        "directory": "C:\\Logs",
        "waitInSeconds": 10,
        "type": "File",
        "includeFileNames": true
      }
    ]
  }
}

The fix for ordering of the waitInSeconds seem to work.

[bobsira]

@mloskot please confirm if the issue still exists in this binary -> https://minikubevhdimagebuider.blob.core.windows.net/versions/LogMonitor.exe

It has the change you've suggested. if it's there we can move this fix to a different PR and let this handle the parser fix

[mloskot]

@bobsira Hmm, I've just tested LogMonitor.exe from that URL

Invoke-WebRequest -Uri 'https://minikubevhdimagebuider.blob.core.windows.net/versions/LogMonitor.exe' -OutFile C:/LogMonitor.exe -UseBasicParsing

and this version is reported inside the container - am I using the right custom ad-hoc build of yours?

but I can't see any difference

Here is my config inside the container

and logs location

[bobsira]

Hmmm, strange that should be the binary with the change. I'll go ahead and split the PR for now. I have a feeling this issue might be coming from another place in the code as well so let's have it addressed in a different PR.

[mloskot]

Good idea. Let's take baby steps. The overall direction seems fine though 😊