LoopBack does not read port property from config.json (or other config files)

Question

So I want to run multiple LoopBacks listening different ports (makes dev easier). I can achieve this by using PORT=808x node ., but I would prefer a configured alternative.

When I tried to use the configs, I noticed strange behavior. Other configs, such as the restApiRoot matches whatever I write for it in the server/config.json, but the port is always 8080, unless I use env variables or such. I checked the documentation for all configuration files LoopBack reads, non of them has new value for port. Where does that port value come from? How can I force it to use the one in server/config.json or in similar official configuration files?

UPDATE: My server/server.js server/config.json and package.json files

When I start this with node . command, the port variable is 8080 instead of 8082 and when I wget, the response (404) comes from 8080 and 8082 gives no response, as there is no server serving that port.

package.json

{
  "name": "external-server",
  "version": "1.0.0",
  "main": "server/server.js",
  "scripts": {
    "pretest": "jshint ."
  },
  "dependencies": {
    "compression": "^1.0.3",
    "cors": "^2.5.2",
    "loopback": "^2.22.0",
    "loopback-boot": "^2.6.5",
    "loopback-component-explorer": "^2.1.0",
    "loopback-connector-mysql": "^2.4.1",
    "loopback-datasource-juggler": "^2.39.0",
    "serve-favicon": "^2.0.1"
  },
  "devDependencies": {
    "jshint": "^2.5.6"
  }
}

server/server.js

var loopback = require('loopback');
var boot = require('loopback-boot');

var app = module.exports = loopback();

app.start = function() {
  // start the web server
  return app.listen(function() {
    app.emit('started');
    console.log(app.get('port'))
    var baseUrl = app.get('url').replace(/\/$/, '');
    console.log('Web server listening at: %s', baseUrl);
    if (app.get('loopback-component-explorer')) {
      var explorerPath = app.get('loopback-component-explorer').mountPath;
      console.log('Browse your REST API at %s%s', baseUrl, explorerPath);
    }
  });
};

// Bootstrap the application, configure models, datasources and middleware.
// Sub-apps like REST API are mounted via boot scripts.
boot(app, __dirname, function(err) {
  if (err) throw err;

  // start the server if `$ node server.js`
  if (require.main === module)
    app.start();
});

server/config.json

{
  "restApiRoot": "/api",
  "host": "0.0.0.0",
  "port": 8082
}

Answer 1

Okay, it seems that when I run LoopBack with sudo, the configuration files are applied. Very confusing.

So the command node . will lead to wrong port and sudo node . will read the port from the server/config.json. It seems like other configuration parameters are read correctly, even without sudo, for some reason PORT is a special case. There is a realted answer, which shows that this is a NodeJS + Express issue, not a LoopBack issue.