Debug Remote Heroku Node Server with Visual Code

SSH into heroku server from your local machine.

  heroku ps:exec -a <APP>

On the heroku server, find the node process ID (PID) by running ps aux or ps aux | grep -i node command. In the below sample output, the PID is 46.

  ~ $ ps aux
  USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
  ...
  user        46  0.0  0.0 767320 58160 ?        Sl   21:35   0:00 node ./bin/www
  ...

On the heroku server, run the below command to send SIGUSR1 signal to the node process to enable its debugger. Check documentation here.

  kill -usr1 <PID>

On your local machine, run the port forward command. (Note: Before running the below command, running lsof -i:9229 should not return any PID. This is to make sure the port is vailable on your local machine.)

  heroku ps:forward 9229 -a <APP>

On your local Machine VS Code, add this configuration.

  {
      "type": "node",
      "request": "attach",
      "name": "Remote Heroku: Debug Remote Server",
      "address": "localhost",
      "port": 9229,
      "protocol": "inspector",
      "localRoot": "${workspaceFolder}",
      "remoteRoot": "/app"
  }