Is It possible that vs code LSP client can connect with server use tcp or websocket?

[hasegetc]

• just as this page describ: "https://docs.microsoft.com/en-us/visualstudio/extensibility/language-server-protocol?view=vs-2019", The actual transport channel can either be stdio, sockets, named pipes, or node ipc
• this page notice that we can use tcp, "https://docs.microsoft.com/en-us/visualstudio/extensibility/adding-an-lsp-extension?view=vs-2019"
• but I cant find the demo that lsp client transport data with server use tcp (not use ip + port), just use port for note IPC
• is it possible VS Code LSP client can connect with server use tcp or websocket?

[rcjsuen]

@hasegetc The documents you are linking to are for Visual Studio but I assume you are talking about Visual Studio Code.

vscode-languageserver-node/client/src/node/main.ts

Lines 52 to 57 in 3eddc56

	export enum TransportKind {
	stdio,
	ipc,
	pipe,
	socket
	}

You should be able to use TransportKind.socket to tell the LSP client in VS Code to connect using TCP.

[hasegetc]

@rcjsuen thank you very much for you reply. but just in the vscode-languageserver-node/client/src/node/main.ts write, there just transport.port in the source code, I cant find where is transport.ip. is TransportKind.socket just for IPC connect? or how can I use ip and port in TransportKind.socket to connect to remote lsp server?

[dbaeumer]

I have never tested connecting to a server using WebSockets. From my experiences in VS Code extension host this needs some special code since you need to implement some special hand shaking (see https://github.com/microsoft/vscode/blob/645f5850141b13b3d194e389eabf83eacc785bb5/src/vs/base/parts/ipc/node/ipc.net.ts#L79-L257)

I am open for a PR that adds this.

[hasegetc]

• @dbaeumer thank you very much
• I find the answer by you :How do I use tcp/socket? language-server-protocol#604. "What needs to be understood is that for connection timing issues the server is actually a client and the client is the server in terms of opening the ports."
• does you mean that the vs code lsp extention is the tcp server, and the lsp server is the tcp client, the lsp server use the lsp client's ip + port to establish the connection?

[hasegetc]

I find the solution

export function activate(context: ExtensionContext) {
	let connectionInfo = {
		port: 5007,
		host: "192.168.0.152"
    };

	// The server is implemented in node
	let serverModule = context.asAbsolutePath(
		path.join('server', 'out', 'server.js')
	);
	// The debug options for the server
	// --inspect=6009: runs the server in Node's Inspector mode so VS Code can attach to the server for debugging
	let debugOptions = { execArgv: ['--nolazy', '--inspect=6009'] };

	// If the extension is launched in debug mode then the debug server options are used
	// Otherwise the run options are used
	// let serverOptions: ServerOptions = {
	// 	run: { module: serverModule, transport: TransportKind.socket },
	// 	debug: {
	// 		module: serverModule,
	// 		transport: TransportKind.socket,
	// 		options: debugOptions
	// 	}
	// };

	let serverOptions = () => {
        // Connect to language server via socket
        let socket = net.connect(connectionInfo);
        let result: StreamInfo = {
            writer: socket,
            reader: socket
        };
        return Promise.resolve(result);
    };

	// Options to control the language client
	let clientOptions: LanguageClientOptions = {
		// Register the server for plain text documents
		documentSelector: [{ scheme: 'file', language: 'plaintext' }],
		synchronize: {
            fileEvents: workspace.createFileSystemWatcher('**/*.*')
        }
	};

	// Create the language client and start the client.
	client = new LanguageClient(
		'languageServerExample',
		'Language Server Example',
		serverOptions,
		clientOptions
	);

	// Start the client. This will also launch the server
	client.start();
}