Adding Cloud Logging to Express Application

This guide explains how to integrate cloud logging into your Express application using the cloud-app-logger library. Each log will include a unique request ID for tracking the entire journey of a request, including request body, response, and any additional logs or errors for that request.

Note: Currently, only Google Cloud Logging is supported.

Steps to Add Cloud Logging

1. Add the following to your package.json:

   "cloud-app-logger": "^0.0.17"

2. Add the following environment variables:

   LOGGING_PROJECT_ID=<YOUR_PROJECT_ID> # Name for the Google Cloud project where logs should be stored
   LOGGING_ENABLED=true # Enable logs being sent to the cloud. Keep false when running local code
   LOGGING_LOG_NAME=<LOG_NAME> # Log name in Google Cloud. For example, app-name-staging

3. Import the necessary functions wherever your Express app object is created:

   import { initAppLogger, configureErrorLogging, configureRequestLogging } from 'cloud-app-logger';
      
   // Call this as early as possible but after calling dotenv.config()
   initAppLogger();

4. After adding body parsing middlewares such as json or urlencoded, configure request logging:

   app.use(express.json());
   app.use(express.urlencoded({ extended: false }));
      
   // Call the function here !!!
   configureRequestLogging(app);

5. Call the error logging configuration function after adding all middlewares/routes:

   configureErrorLogging(app);

6. Call the logUnhandledExceptions function in each file where you have defined a router after importing Router or Express:

   import { Router, Request, Response } from 'express';
   import { logUnhandledExceptions } from 'cloud-app-logger';
      
   // Call the function here
   logUnhandledExceptions();
      
   const router = Router();

7. Run the project, and logging should now be enabled and visible in Google Cloud Logging.