@apolitical/server/src/services/express.service.js

Node.js module to encapsulate Apolitical's express server setup

'use strict';

module.exports = ({ express, httpTerminator, logger, expressLoader }) => {
  let app = null;
  let terminator = null; // I need your clothes, your boots and your motorcycle

  function expressRunner(app, port) {
    return new Promise((resolve, reject) => {
      if (!port) {
        return reject(new Error('Cannot start server without port option'));
      }
      const server = app.listen(port, () => {
        const runnerLogger = logger.where(__filename, 'expressRunner');
        runnerLogger.info(`Server listening on ${port}`);
        return resolve();
      });
      terminator = httpTerminator.createHttpTerminator({ server });
    });
  }

  async function startup(opts) {
    // Create, load and run the express app
    if (!app) {
      app = express();
      await expressLoader(app, opts);
      await expressRunner(app, opts.port);
    }
    return app;
  }

  async function shutdown() {
    // Terminate process and clean-up variables
    await terminator.terminate();
    app = null;
    terminator = null;
  }

  return { startup, shutdown };
};