backend/app.js

// OwlBoard - © Fred Boniface 2022 - Licensed under GPLv3 (or later)

// Please see the included LICENSE file.  Statically served fonts are
// licensed separately, each folder contains a license file where a 
// different license applies.

/* global process */

console.log('Initialising OwlBoard');
const mode = process.env.NODE_ENV || 'development';

// External Requires
const express     = require('express');
const app         = express();

// Middleware
const compression = require('compression');
const rateLimit   = require('express-rate-limit');
const authenticate= require('./src/middlewares/auth.middlewares');

// Internal Requires
const log      = require('./src/utils/log.utils');
const version  = require('./src/configs/version.configs');
const listRtr  = require('./src/routes/list.routes');
const ldbRtr   = require('./src/routes/ldb.routes');
const kubeRtr  = require('./src/routes/kube.routes');
const findRtr  = require('./src/routes/find.routes');
const issueRtr = require('./src/routes/issue.routes');
const statRtr  = require('./src/routes/stats.routes');
const regRtr   = require('./src/routes/registration.routes');
const pisRtr   = require('./src/routes/pis.routes');
const trainRtr = require('./src/routes/train.routes');

// Set Server Configurations
const srvListen = process.env.OWL_SRV_LISTEN || '0.0.0.0';
const srvPort   = process.env.OWL_SRV_PORT || 8460;

const limiter = rateLimit({
  windowMs: 15 * (60 * 1000), // 15 minutes
  max: 100, // Limit each IP to 100 requests per `window` (here, per 15 minutes)
  standardHeaders: true, // Return rate limit info in the `RateLimit-*` headers
  legacyHeaders: true, // Disable the `X-RateLimit-*` headers
});

// Print version number:
log.out(`app: Starting OwlBoard in ${mode} mode`, 'init');
log.out(`app: Starting OwlBoard - Backend Version: ${version.app} - ` + 
        `API versions: ${version.api}`, 'init');

// Test for required vars:
// const varTest = require('./src/utils/varTest.utils');
// var startTest = await varTest.varTest();
//console.log("Required Vars Missing:", startTest.missing_required);
//console.log("Desired Vars Missing:", startTest.missing_desired);
// if startTest.pass == false
// console.log("Unable to start, missing required vars")
// exit app

// Express Error Handling:
app.use((err, req, res, next) => {
  const statusCode = err.statuscode || 500;
  console.error(err.message, err.stack);
  res.status(statusCode).json({'message': err.message});
  return;
});

// Global Middleware:
app.use(express.json()); //JSON Parsing for POST Requests
app.use(compression()); // Compress API Data if supported by client
app.use(limiter);

// Unauthenticated Routes
app.use('/api/v1/list', listRtr);
app.use('/api/v1/ldb', ldbRtr);
app.use('/api/v1/kube', kubeRtr);
app.use('/api/v1/find', findRtr);
app.use('/api/v1/issue', issueRtr);
app.use('/api/v1/stats', statRtr);
app.use('/api/v1/register', regRtr);

// Authented Routes
app.use('/api/v1/ldbs', authenticate, (req, res) => res.status(501).json({status: 'not implemented'}));
app.use('/api/v1/pis', authenticate, pisRtr);
app.use('/api/v1/auth/test', authenticate, (req, res) => res.status(200).json({status: 'ok', message: 'Authentication successful'})); // Returns 401 if auth failed, 200 if successful.
app.use('/api/v1/train', /*authenticate,*/ trainRtr); // Disable authentication during testing

// Number of proxies:
app.set('trust proxy', 4);
mode === 'development'
  ? app.get('/api/v1/ip', (req, res) => res.send(req.ip))
  : null;

// Start Express
app.listen(srvPort, srvListen, (error) =>{
  if(!error) {
    log.out(`app.listen: Listening on http://${srvListen}:${srvPort}`, 'init');
    log.out('app.listen: State - alive', 'init');
  } else {
    log.out(`app.listen: Error occurred, server can't start ${error}`, 'err');
  }
});