This is an example of integrating Winston & Morgan Logging with Loopback 4. It uses the express-composition example that mounts the LoopBack 4 REST API on a simple Express application. See here for the express-composition example.

The Express application in this example is based on the Express Generator

You'll need to install the LoopBack 4 CLI toolkit to scaffold your own application:

npm i -g @loopback/cli

You can begin by visiting the official tutorial page for mounting Loopback 4 in Express.

If you'd like to see the final results of this tutorial as an example application, follow these steps:

1. Download/Clone this project.

2. Jump into the directory and then install the required dependencies:

   cd loopback4-express-with-logging
   npm install

3. Finally, start the application!

   $ npm start
   
   Server is running at http://127.0.0.1:8000

4. Open the Loopback Explorer at http://127.0.0.1:8000/api/explorer/

Feel free to look around in the application's code to get a feel for how it works.

import { winstonLogger } from "./lib/logger";
// log the error.
winstonLogger.error(
  `${err.status || 500} - ${err.message} - ${req.originalUrl} - ${
    req.method
  } - ${req.ip}`
);

You can use the /errorlogger endpoint to log an error from your front end application as well -

curl -X POST "http://127.0.0.1:8000/api/errorlogger" -H "accept: application/json" -H "Content-Type: application/json" -d "{\"message\":\"My awesome error message\"}"

Log files are separated out based on the log levels. The logs directory is generated at run time.

Application works with Docker. Use the docker-compose to create your Docker container.

MIT