Double server from CLI

[Arctomachine]

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
  Platform: win32
  Arch: x64
  Version: Windows 10 Pro
Binaries:
  Node: 16.15.1
  npm: N/A
  Yarn: N/A
  pnpm: N/A
Relevant packages:
  next: 12.2.1-canary.1
  eslint-config-next: 12.2.0
  react: 18.2.0
  react-dom: 18.2.0

What browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

CLI

Describe the Bug

I have app.js file in root folder.

const start = require('next/dist/cli/next-start')
start.nextStart()

It starts 2 servers at the same time. It starts dev server instead of production and overwrites contents of .next folder with files of dev server.

> node app.js
ready - started server on 0.0.0.0:3000, url: http://localhost:3000
ready - started server on 0.0.0.0:3000, url: http://localhost:3000

Accessing localhost:3000 returns error 404

Expected Behavior

Only start production server

Link to reproduction

https://github.com/Arctomachine/reproduction-double-server

To Reproduce

1. Run next build
2. Run node app.js

[bengeois]

Also have this issue when deploying on AWS Beanstalk

[QuiiBz]

I don't think the server is started twice:

The first log is coming from

next.js/packages/next/cli/next-start.ts

Line 88 in 6b8e499

Log.ready(`started server on ${host}:${app.port}, url: ${appUrl}`)

and the second one is from

next.js/packages/next/build/output/store.ts

Line 56 in 6b8e499

Log.ready(`started server on ${state.bindAddr}, url: ${state.appUrl}`)

[Arctomachine]

require('next/dist/cli/next-start') alone already starts server and gives one output. If you try only this line, you will get fully working dev server.
But in either case, with 2 outputs it starts malfunctioning dev server, while functioning production is expected.

[QuiiBz]

I searched a bit and the issue first appeared in version 12.1.1-canary.5.

Importing next/dist/cli/next-start without calling nextStart() before this version does not start the server.

edit:
It's a regression from #34836:

When getProjectDir is called, it now also imports next/bin/next.ts, which is itself calling commands[command]().

This command should not be defined, but it fallbacks to defaultCommand, which is dev (that explains why the dev server is also started)

2nd edit:
Opened a PR that fixes the issue: #38274

[github-actions]

This closed issue has been automatically locked because it had no new activity for a month. If you are running into a similar issue, please create a new issue with the steps to reproduce. Thank you.