server.js

const express = require("express");
const next = require("next");
const dev = process.env.NODE_ENV !== "production";
const app = next({ dir: ".", dev });
const handle = app.getRequestHandler();

app.prepare().then(() => {
  const server = express();

  if (!dev) {
    /**
     * Static Files
     */
    server.get("/robots.txt", (req, res) => {
      return res.sendFile("/static/robots.txt");
    });
    server.get("/sitemap.xml", (req, res) => {
      return res.sendFile("/static/sitemap.xm");
    });
  }

  /**
   * Kernels
   */
  server.get("/kernels/:slug", (req, res) => {
    const queryParams = { slug: req.params.slug };
    return app.render(req, res, "/kernels", queryParams);
  });

  /**
   * Catch all
   */
  server.get("*", (req, res) => {
    return handle(req, res);
  });

  server.listen(8080, err => {
    if (err) throw err;
    console.log("> Ready on http://localhost:8080");
  });
});