Remote Xdebug

Debug a remote server with XDebug and PHPStorm

Overview

The IDE (e.g. PHPStorm) is runnung in the local machine and is listening for XDebug connections from a remote server.

XDebug port: 9000

Establish and test an SSH tunnel.

Redirecting all requests from the server that come to port 9000 to the local machine on port 9000

ssh -R 9000:localhost:9000 server_ip_hostname_or_config_alias

If the XDebug runs within a Docker container in the server, setup the tunnel with the command:

ssh -R \*:9000:localhost:9000 server_ip_hostname_or_config_alias

This makes the tunnel open to the public.

Allow Remote connection

By default, OpenSSH only allows connecting to remote forwarded ports from the server host Edit the sshd_config

sudo joe /etc/ssh/sshd_config

Set

GatewayPorts yes

And restart SSH

sudo service ssh restart

Confirm that port 9000 accepts connection from any host

Run

sudo netstat -plnt

And confirm that you get 0.0.0.0 in the Local Address.

Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:9000            0.0.0.0:*               LISTEN      49998/sshd: skounis 

Test the tunnel

In the local machine start a server that is listening to port 9000

nc -l 9000

In the server connect to port 9000 and send some messages (text)

nc localhost 9000

Any character we type should apear in the terminal in the local machine.

Debug with PHPStorm

Deployment Server

Go to "Preferences > Build, Execution, Deployment > Deployment".

Create a new server

And set

Connection

Mappings

PHP Server

Go to "Preferences > Languages & Frameworks > PHP > Servers".

Create a new server

Local files

You need to have an exact copy of the files in the local filesystem.

1. Set the IP of the server
2. Map the files by using absolute paths for local and remote folders.

Validate the server

Select "Run > Web Server Debug Validation"

1. Select Remote Web Server
2. Set the path to the folder that is server by the webserver
3. Select the Deployment server
4. Press "Validate"

Listen for connections

Select the PHP Server and start listening for connection.

Browser

Install a plugin that sets the debug session

• Chrome: https://chrome.google.com/webstore/detail/xdebug-helper/eadndfjplgieldjbigjakmdgkmoaaaoc

Visit the public URL with the plugin enabled.

PHPStorm expects the cookie value XDEBUG_SESSION=PHPSTORM; in the request header.

References

• Sending TCP/UDP packets using Netcat
• Understanding and using Xdebug with PHPStorm and Magento remotely
• SSH Port Forwarding Example
• Check listening ports
• How to make ssh tunnel open to public?
• SSH Tunnel - Local and Remote Port Forwarding Explained With Examples
• sshd_config - SSH Server Configuration

PHPStorm

• Create new PhpStorm project from remote server with automatic sync of source files