Proper way to remote debugging in NextJS

[davidchingmy]

Like any other node app, we can enable remote debugging using NODE_OPTIONS='--inspect=0.0.0.0:9229' next dev. I have setup this together with docker compose config:

  app:
    working_dir: '/app'
    image: 'node:18'
    ports:
      - '3000:3000'
      - '9229:9229'
    restart: unless-stopped
    volumes:
      - '.:/app'
    command: bash -c 'npm install && npm run dev'

Confirm that debugger is running:

Open inspector browser at chrome://inspect:

No file like _index.tsx or _app.tsx found in Sources tab. Do anyone able to do this?

[icyJoseph]

I tried this https://nextjs.org/docs/advanced-features/debugging and I could only see a few files, doing cmd + P, I couldn't find the webpack protocol. I wonder if Chrome is blocking it somehow... for security reason perhaps?

[taiweituan]

Thanks, but still doesn't work for me except for this comment.

Are you still running NextJS inside a container? The debugger only works if I run the NextJS app straight from the terminal (not in a Docker container) for me.

[icyJoseph]

Ah right, this issue was about using it through Docker, but then would it not be enough to forward the Debugger ports as well? Probably easier with compose.

[taiweituan]

I do use docker-compose which has the following setting

    ports:
      - 3000:3000
      - 9229:9229
    expose:
      - 9229

, but the problem is the --inspect needs to specify 0.0.0.0 so we can reach the ports inside the container.

Currently, the inspector only works by not specifying anything for --inspect so the debug instance can increment itself (9229 & 9230). However, if I specify anything for --inspect (i.e. inspect=0.0.0.0, inspect=:9229, or inspect=0.0.0.0:9229 (which I originally had before upgrading NextJS from older version to 13+ and used to worked), it will throw the

/usr/local/bin/node:  must be 0 or in range 1024 to 65535.

on app start-up.

[icyJoseph]

Isn't --inspect-brk=0.0.0.0 or something like that, that you need? And also do the same for port 9230

[taiweituan]

I did, and it doesn't really matter since giving either --inspect or --inspect-brk with IPv4 value will throw

/usr/local/bin/node:  must be 0 or in range 1024 to 65535.

[maurovargascom]

I'm having the same problem. I can't inspect a Next.js app running on a Docker container using Compose

[jbccollins]

Any update on this?

[dcole2929]

Same problem. Will add when using the NODE_OPTIONS='--inspect=0.0.0.0:9229' next dev I get the following error in console

Debugger listening on ws://0.0.0.0:9229/3ed8ecb5-4b4f-44fd-968d-f11acec86c41
For help, see: https://nodejs.org/en/docs/inspector
Starting inspector on 0.0.0.0:9229 failed: address already in use
    the --inspect option was detected, the Next.js router server should be inspected at port 0

[mjanveaux]

Same problem. Is there a solution for this?

[chandra2607]

anyone got a better workaround it?
I tried various solutions based on some r&d but none of them worked.i am using docker-compose for managing my services.i tried port forwarding with different services but they didn;t work.

@taiweituan @davidchingmy did you got some solution around it ?