configuring custom logger

[jeffreybradley1963]

If I configure a custom logger, does it get passed into the request object? Is it possible for me to pass it on down from the controller to the service or do I need to handle logging from my business logic differently?

[alesancor1]

It does not get passed to request object by default. There are two ways you could use your logger in controllers:

Solution 1

Export an instanciated logger, instead of the winston.createLogger function:

// logger.js

const winston = require('winston');

const logger = winston.createLogger({
  level: 'info',
  format: winston.format.json(),
  defaultMeta: { service: 'user-service' },
  transports: [
    new winston.transports.Console({
        format: winston.format.simple(),
    })
  ]
});

module.exports = logger;

Then you can import that logger in your controllers file whenever you need it:

// controller.js

const logger = require('./logger.js');

module.exports.controller = function someController(req, res) {
    logger.info("Log some info");
   /* Controller logic */
}

Solution 2

Create a simple middleware function that inserts the logger in the request object:

// index.js

const logger = require("./logger.js");

const middleware = (req, _res, next) => { req.logger = logger; next() }

oasTools.use(middleware, authCfg, 0);
oasTools.initialize(app).then(() => ...)

Then you can access req.logger in your controllers logic.

// controller.js

module.exports.controller = function someController(req, res) {
    req.logger.info("Log some info");
   /* Controller logic */
}