XDebug on port 9000 with a virtual machine - EADDRINUSE :::9000

Question

I am running my Symfony application on a VirtualBox VM. PHP is running with XDebug, and it is properly configured. I know this because other people have managed to make it work with a snapshot of the same VM.

When I try to configure in VS Code XDebug, I use the following launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Listen for XDebug",
            "type": "php",
            "request": "launch",
            "port": 9000
        },
        {
            "name": "Launch currently open script",
            "type": "php",
            "request": "launch",
            "program": "${file}",
            "cwd": "${fileDirname}",
            "port": 9000
        }
    ]
}

But when I click on "Start Debugging: Listen for XDebug", I get the following error:

ERROR: listen EADDRINUSE :::9000

I tried killing the process that is using that port... and for my surprise that was the virtual machine I was trying to connect to.

What did I miss in this configuration?

Answer 1

You are trying to do a launch operation in your launch.json, which will result as vscode trying to start a new instance of php with an xdebug on port 9000.

Try replacing your launch config by an attach config.

Hope it helps.

Answer 2

port 9000 is frequently used by default configurations of other apps (for example native apache on MacOsX), also VMs, Docker containers, etc...

A reliable solution would be - to use a different port. For example, 9001 :)

That means:

• updating your IDE xdebug configs from port 9000 to 9001;

• adding to your php.ini (xdebug.ini) the line

  xdebug.remote_port=9001
  

Also, you can check your 9000 port usage by some tool like telnet

Answer 3

I found the answer myself just about.

The problem was laying on the configuration of Virtualbox.

On the Network settings, there was a port forwarding for the port 9000, which blocked my debugger from running locally. Once removed, it worked without problem.

Answer 4

On MacOS we can use the terminal to determine what is open on port 9000 with the following:

sudo lsof -nP -i4TCP:9000 | grep LISTEN

We can use sudo above so we see processes that are not owned by the logged in account.

For example when I did the above I got:

php-fpm 110 root    6u  IPv4 0x5cb825c4aa80be09      0t0  TCP 127.0.0.1:9000 (LISTEN)
php-fpm 261 _www    0u  IPv4 0x5cb825c4aa80be09      0t0  TCP 127.0.0.1:9000 (LISTEN)
php-fpm 262 _www    0u  IPv4 0x5cb825c4aa80be09      0t0  TCP 127.0.0.1:9000 (LISTEN)

We can then end the processes with this command:

sudo kill 110

Then we will have the port free so we can start up Xdebug without a conflict.

That solved it for me.