Re Initialization express Application - node.js

Question

I have node.js application, which was built on express.js framework.
const app = express();
require('./config')(app);
require('./services')(app);
./config/config.js we instantiate config:
module.exports = function (app) {
const conf = {APIKey: 1234567890, url: '<someurl>'};
app.set('config', conf);
};
./services/APIService.js we create service instance(singleton)
module.exports = (app) => {
app.set('apiService', new APIService(app));
};
function APIService(app) {
const config = app.get('config');
this.key = config.APIKey;
};
APIService.prototype.sendRequest = () => {
const config = app.get('config');
this._send(config.url, 'some text');
};
Or, service2
module.exports = function(app) {
const config = app.get('config');
const myMod = require('myMod')(config.APIKey);
}
Cool, all works correct. But sometime administrator will change some config data. So, we create new config, set him to
newConf = {APIKey: 1234000000, url: '<some_new_url>'};
app.set('config', newConf);
APIService.sendRequest, will send request to CHANGED url, but APIService.key still unchanged. And myMod already instantiated with old config data.
We need write some setter methods, like this
//for APIService
APIService.prototype.setConfig = () => {
const config = app.get('config');
this.key = config.APIKey;
};
//for service 2
/* change const myMod to let myMod and create method for overriding */
or bang! kill and restart node.js server process. Bad idea. Maybe exist some method for this goal, something like app.restart() for safely reinitializing application(or, maybe, his parts)?

Answer 1

Did you try to call app.set('apiService', new APIService(app)); again ? or just have getter and setter on the prototype for your params.
Better way should be to have a new APIService object at each new request with a middleware, somehting like :
app.use(function (req, res, next){
req.api = new APIService(app);
next();
});
And use req.api.