How to build next.js production?

Question

I try to get a production build in next.js to run it on my server but I can't build next.js production build when I try

npm run build

Does anyone know how to get a prod build in next.js working correctly I did everything in the next.js documentation but always get this error below. If I do a dev build it works just fine but trying prod build results in errors.

I did also next build many times and reinstalled all node_modules packages still having this error.

it always shows me in terminal

Error: Could not find a valid build in the '/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/.next' directory! Try building your app with 'next build' before starting the server.
    at Server.readBuildId (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/node_modules/next/dist/server/next-server.js:753:15)
    at new Server (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/node_modules/next/dist/server/next-server.js:80:25)
    at module.exports (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/node_modules/next/dist/server/next.js:6:10)
    at Object.<anonymous> (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/next.config.js:6:13)
    at Module._compile (internal/modules/cjs/loader.js:707:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:718:10)
    at Module.load (internal/modules/cjs/loader.js:605:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:544:12)
    at Function.Module._load (internal/modules/cjs/loader.js:536:3)
    at Module.require (internal/modules/cjs/loader.js:643:17)
    at require (internal/modules/cjs/helpers.js:22:18)
    at loadConfig (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/node_modules/next/dist/server/config.js:47:28)
    at _callee2$ (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/node_modules/next/dist/build/index.js:52:42)
    at tryCatch (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/node_modules/regenerator-runtime/runtime.js:62:40)
    at Generator.invoke [as _invoke] (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/node_modules/regenerator-runtime/runtime.js:288:22)
    at Generator.prototype.(anonymous function) [as next] (/mnt/c/Users/NZXT_YOLO/Desktop/New folder (2)/learnnextjs-demo/node_modules/regenerator-runtime/runtime.js:114:21)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! hello-next@1.0.0 build: `next build`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the hello-next@1.0.0 build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/kk/.npm/_logs/2018-12-10T19_58_00_588Z-debug.log

server.js

const express = require("express");
const next = require("next");

const port = parseInt(process.env.PORT, 10) || 3000;
const dev = process.env.NODE_ENV === "production";
const app = next({ dev });
const handle = app.getRequestHandler();

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

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

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

next.config.js

const express = require("express");
const next = require("next");

const port = parseInt(process.env.PORT, 10) || 3000;
const dev = process.env.NODE_ENV === "production";
const app = next({ dev });
const handle = app.getRequestHandler();

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

  server.get("/projects/:page", (req, res) => {
    const page = req.params.page;
    let file = "";
    switch (page) {
      case "example1":
        file = "/projects/example1";
        break;
      case "example2":
        file = "/projects/example2";
        break;
    }
    return app.render(req, res, file, { page });
  });

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

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

package.json

 {
  "name": "hello-next",
  "version": "1.0.0",
  "description": "",
  "main": "server.js",
  "scripts": {
    "dev": "node server.js",
    "build": "next build",
    "export": "next export"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@zeit/next-sass": "^1.0.1",
    "express": "^4.16.4",
    "next": "^7.0.2",
    "react": "^16.6.3",
    "react-dom": "^16.6.3",
    "redux": "^4.0.1",
    "video-react": "^0.13.1"
  }
}

I plan to run this next.js site using node on my AWS server. But to do this I need to get production build of react.js currently I can run just a development build.

Answer 1

There are 3 ways todo it:-

way 1: use next build instead of npm run build

way 2: npm run build npm install -g serve serve -s build more info: https://create-react-app.dev/docs/deployment/

way 3: after npm run build, Remove / from JS,CSS links from /static/index.html file. eg. replace these 2 lines

<script defer="defer" src="/static/js/main.aa87bc08.js"></script>
<link href="/static/css/main.073c9b0a.css" rel="stylesheet"/>

with these 2 lines

<script defer="defer" src="static/js/main.aa87bc08.js"></script>
<link href="static/css/main.073c9b0a.css" rel="stylesheet" />

now it even work on file:///D:/codes/ProjectName/build/index.html

tell me in the comments if none of the 3 ways work, I'll find, try & tell way 4, 5, etc.

Answer 2

next build followed by next start should be the right commands to prepare the build for production and run it.

Here's an example for package.json. if you want to export application to run as a static content, something like hosting it in s3 as a static website, you need to run next export

...
"scripts": {
    "build": "next build",
    "start": "next start",
    "export": "next export"
}
...

Make sure you have the above scripts in your package.json then run the following in order

$ npm run build 
$ npm run start

If you want to start application with specific port, you can specify -p port as argument for npm run command

npm run start -- -p 3232

If you want to incorporate this into a CI/CD pipeline, you need to have Dockerfile, here's a simple example

FROM node:alpine

#copy source 
COPY . /app

# Install deps 
RUN cd /app &&  npm install 

# Build 
RUN npm run build

ENTRYPOINT [ "npm", "run", "start" ]

Still need more explanation or help, don't hesitate to leave a comment and I will be more than happy to assist.

Answer 3

Seems your server.js config is not correct. Please try moving all you have from your next.config.js to server.js make sure the next.config.js file is empty then create a new npm run script:

"prod_start": "NODE_ENV=production node server.js"

Your package.json should then look like this:

{
  "name": "hello-next",
  "version": "1.0.0",
  "description": "",
  "main": "server.js",
  "scripts": {
    "dev": "node server.js",
    "build": "next build",
    "prod_start": "NODE_ENV=production node server.js",
    "export": "next export"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@zeit/next-sass": "^1.0.1",
    "express": "^4.16.4",
    "next": "^7.0.2",
    "react": "^16.6.3",
    "react-dom": "^16.6.3",
    "redux": "^4.0.1",
    "video-react": "^0.13.1"
  }
}

make sure to run: npm run build && npm run prod_start

Then you should have a production build of react running using next.js

Let me know if you got question.

Answer 4

You must launch next build at your root folder and not inside .next/