node inspect fails on node 8.0.0

[rawbin-]

• Version: 8.0.0
• Platform:Darwin Kernel Version 16.6.0
• Subsystem:

node --inspect-brk xxx.js
Debugger listening on ws://127.0.0.1:9229/0f2332ff-8ade-478f-bc82-539beccb434d

the given url could not be opend with chrome ,but succeeded with url below

chrome-devtools://devtools/bundled/inspector.html?experiments=true&v8only=true&ws=127.0.0.1:9229/0f2332ff-8ade-478f-bc82-539beccb434d

[cjihrig]

The ws:// URL is where the debugger is listening, but you need to connect to the chrome-devtools:// URL to actually communicate with it (unless you write your own tool). That's why the latter URL has the ws query string parameter. I think this is working as intended, although the messaging may be confusing. I think the idea was to make the displayed URL more vendor agnostic, with vendor specific instructions included at https://nodejs.org/en/docs/inspector/.

[gmuc]

Same problem!!! Where can I input the ws://127.0.0.1:9229/0f2332ff-8ade-478f-bc82-539beccb434d in chrome developer tools? No hint on https://nodejs.org/en/docs/inspector/.

[evanlucas]

@gmuc try going to chrome://inspect if you are on the latest version of chrome. The target should show there

[gmuc]

I have chrome 58.0.3029 on OSX 10.10.5. My inspect URL from node 8.0 in docker is:

Debugger listening on ws://127.0.0.1:9223/99d7ea20-3e5d-4b18-891c-2aae3a1c69de

I follow https://nodejs.org/en/docs/inspector:

I open chrome://inspect ==> "Target discovery settings" = 127.0.0.1:9223 ==> Done
==> Open dedicated DevTools for Node ==> Debugger appear but no source to debug :-(

In older node versions "node --inspect=9223" output was

chrome-devtools://devtools/bundled/inspector.html?experiments=true&v8only=true&ws=127.0.0.1:9223/b41a882a-060e-437a-8ce7-820855b5aae3

I paste this URL in chrome and debugger work -- very simple!!!

[gibfahn]

cc/ @nodejs/v8-inspector for the usability

If you're running in docker then are you port mapping the container 9223 to your machine's 9223? If you're mapping to a different point you can watch that port with by clicking on the port forwarding button (using 9999 as an example).

[gibfahn]

FWIW once you've got the ports set up, once you open the devtools with the Open dedicated DevTools for Node button, that window will automatically refresh every time you restart the debugger, so you don't have to keep copy-pasting links. That saves a lot of time.

[gmuc]

in my docker-compose.yml I map Ports:
ports:
- "9223:9223"

on "docker ps" I got:

PORTS
0.0.0.0:9223->9223/tcp, 0.0.0.0:3001->3000/tcp

9223 = debugger-port, 3001 = express port

==> no need of port forwarding

@gibfahn "Open dedicated DevTools for Node" very goog idea - but not working for me :-(

This is my screen after press "Open dedicated DevTools for Node" - empty debugger:

Any other ideas for analysis of these problem?
Why inspect print 99d7ea20-3e5d-4b18-891c-2aae3a1c69de if you only need ws://127.0.0.1:9223 for opening debugger?

[gibfahn]

I'm afraid that's the extent of my knowledge, I'm hoping someone from @nodejs/v8-inspector will know more.

[eugeneo]

You can specify custom port (9223) by clicking the "Configure" on the chrome://inspect page. Then Chrome will detect when Node (or any other Chrome protocol server) is running on that port and will show the target.

[gmuc]

It's a problem of node version. I assume the handling of chrome devtools debugprotocol is buggy!

I now downgrade from node 8.0.0 to node 7.0.0 and chrome://inspect show a "Remote Target" ./src/index.js
file:///app/src/index.js and "Open dedicated DevTools for Node" open Debugger and show me source.
The debug link like
chrome-devtools://devtools/bundled/inspector.html?experiments=true&v8only=true&ws=127.0.0.1:9223/b41a882a-060e-437a-8ce7-820855b5aae3

working!!!

I try 7.8.0 too ==> same problems as 8.0.0

[robertjustjones]

Thanks @gmuc. I've done the binary search, and 7.4.0 works for me, 7.5.0 does not.

[Trott]

I imagine people have updated to latest Chrome by now and everything works with Node.js 8.2.1. If that's just wishful thinking on my part, please leave a comment or (if GitHub lets you) re-open. Thanks.

[darcyclarke]

@gmuc @rawbin- You might find this helpful; I just launched a tool to wrap the node --inspect command and automatically open the devtools panel for you (it's called rawkit). It does require installing a Chrome Extension (which is the only way to open that kind of url automatically) but it essentially resolves this compatibility issue with the type of link generated from --inspect or --inspect-brk (ie. it checks for the websocket url ws:// and normalizes back to the chrome-devtools: link).

Feel free to check it out and let me know if you have any problems with it: https://github.com/darcyclarke/rawkit

I've also added it to the list of available/optional Node.js Chrome Debugging tools here: https://github.com/nodejs/nodejs.org/pull/1331

Edit: I could also print out the normalized URL for you if that's the ideal... maybe make an issue/PR against the repo?

[gibfahn]

@darcyclarke I think the original issue was to do with running node --inspect inside a docker container, does rawkit work in docker?

[darcyclarke]

@gibfahn yep. Again, I normalize the chrome-devtools:// URL from the output of node --inspect so if you're running a newer version of node and get the ws:// socket reference then we can provide you with a relevant debugging URL. That said, I currently do not output that reference; it is just used to immediately open the devtools. As mentioned, I definitely could add that feature behind some kind of flag (/me runs to add that feature).

[gmuc]

Now it work. My mistake: "--inspect 0.0.0.0:9222" is related to internal port of docker container and not of the host.

The container run on a host. In dockfile from container is a mapping from internal 9222 to a port of the host i.e. 9226. Chrome run on the host and use this localhost:9226 connection for debugging with chrome-dev-tools. It was a network problem and not a problem of the node-version! Thats it!!!
Details: https://nodejs.org/en/docs/guides/debugging-getting-started/