Terraform-ls produces huge amount of log entries

[jpaju]

Hi!

When using terraform-ls with the default configuration, it produces a huge number (10-20k rows per minute) and fills the helix.log file. All the rows in the log file are like this:
2024-02-14T18:04:15.178 helix_lsp::transport [ERROR] terraform-ls err <- "2024/02/14 18:04:15 rpc_logger.go:53: Response to \"textDocument/references\" (ID 6): []\n".

It seems that Helix interprets the responses from terraform-ls as errors 🤔 I'm not sure whether this is an issue with Helix, or terraform-ls not adhering to the LSP spec.

Is it possible to suppress the logging Helix does per LSP? Any other solutions for this?

[the-mikedavis]

See

helix/helix-lsp/src/transport.rs

Line 74 in 4df08dd

tokio::spawn(Self::err(transport.clone(), server_stderr));

and

helix/helix-lsp/src/transport.rs

Lines 139 to 151 in 4df08dd

	async fn recv_server_error(
	err: &mut (impl AsyncBufRead + Unpin + Send),
	buffer: &mut String,
	language_server_name: &str,
	) -> Result<()> {
	buffer.truncate(0);
	if err.read_line(buffer).await? == 0 {
	return Err(Error::StreamClosed);
	};
	error!("{language_server_name} err <- {buffer:?}");
	Ok(())
	}

We log everything the server sends over its stderr as an error. Some language servers use stderr as a logging backend since it's simpler (and I suppose tidier) than having a dedicated log file. It looks like it's possible to configure a file to send the logs to instead of stderr and terraform-ls is looking into changing their logging strategy hashicorp/terraform-ls#1271. I would recommend adding the arguments to redirect the logs to /dev/null (though I don't think that's crossplatform) or to a file of your choice. Ideally this would be solved upstream though

[jpaju]

Huge thanks for the lightning fast and accurate answer! 🙏

The explanation makes perfect sense and, like you suggested, I was able to stop flooding the logs with this config in languages.toml

[language-server.terraform-ls]
command = "terraform-ls"
args = ["serve", "-log-file", "/dev/null"]