feat: Enhance SSH tunnel handling with Unix socket support

Support forwarding Unix sockets in SSH tunnels by extending
`SSHLocalTunnel`. Update logic to detect and handle remote Unix socket
configurations.

Signed-off-by: Sven Sager <akira@narux.de>

src/revpicommander/helper.py

@@ -16,6 +16,7 @@ from re import search
 from threading import Lock
 from uuid import uuid4
 from xmlrpc.client import Binary, ServerProxy, Transport
+from configparser import ConfigParser
 
 from PyQt5 import QtCore
 import asyncssh
@@ -365,10 +366,12 @@ class ConnectionManager(QtCore.QThread):
 
         ssh_tunnel_server = None
         ssh_tunnel_port = 0
+        ssh_tunnel_socket = None
 
         socket.setdefaulttimeout(revpi_settings.timeout)
 
         if revpi_settings.ssh_use_tunnel:
+            # We first connect to find out which target to tunnel
             ssh_tunnel_server = SSHLocalTunnel(
                 revpi_settings.port,
                 revpi_settings.address,
@@ -377,6 +380,37 @@ class ConnectionManager(QtCore.QThread):
             try:
                 ssh_tunnel_port = ssh_tunnel_server.connect_by_credentials(revpi_settings.ssh_user, ssh_pass)
 
+                # Check for Unix socket on remote system
+                try:
+                    stdout, stderr = ssh_tunnel_server.send_cmd("cat /etc/revpipyload/revpipyload.conf")
+                    if stdout:
+                        config = ConfigParser()
+                        config.read_string(stdout)
+                        if config.has_section("XMLRPC"):
+                            bindip = config.get("XMLRPC", "bindip", fallback="").strip()
+                            if bindip == "socket":
+                                ssh_tunnel_socket = "/run/revpipyload/xmlrpc.socket"
+                            elif bindip.startswith("/") or bindip.startswith("./"):
+                                ssh_tunnel_socket = bindip
+
+                        if ssh_tunnel_socket:
+                            log.debug("Using remote unix socket: %s", ssh_tunnel_socket)
+                            # Forward local port 0 (dynamic) to remote unix socket
+                            ssh_tunnel_server.disconnect()
+                            ssh_tunnel_server = SSHLocalTunnel(
+                                ssh_tunnel_socket,
+                                revpi_settings.address,
+                                revpi_settings.ssh_port
+                            )
+                            ssh_tunnel_port = ssh_tunnel_server.connect_by_credentials(
+                                revpi_settings.ssh_user, ssh_pass
+                            )
+                        else:
+                            log.debug("Using remote TCP socket: %s", bindip)
+
+                except Exception as e:
+                    log.warning(f"Could not check remote config for unix socket: {e}")
+
                 if getattr(revpi_settings, "ssh_enable_revpipyload", False):
                     ssh_tunnel_server.send_cmd("sudo systemctl enable --now revpipyload")
 
@@ -723,7 +757,7 @@ def create_server_proxy(revpi_settings: RevPiSettings, ssh_tunnel_port: int = No
     :param ssh_tunnel_port: Use this port if an SSH tunnel is already established
     :return: ServerProxy instance
     """
-    if revpi_settings.is_unix_socket:
+    if not ssh_tunnel_port and revpi_settings.is_unix_socket:
         return ServerProxy("http://localhost", transport=UnixStreamTransport(revpi_settings.address))
 
     if ssh_tunnel_port:

src/revpicommander/ssh_tunneling/server.py

@@ -18,15 +18,15 @@ log = getLogger("ssh_tunneling")
 
 class SSHLocalTunnel:
 
-    def __init__(self, remote_tunnel_port: int, ssh_host: str, ssh_port: int = 22):
+    def __init__(self, remote_target: Union[int, str], ssh_host: str, ssh_port: int = 22):
         """
-        Connect to a ssh remote host and tunnel a port to your host.
+        Connect to a ssh remote host and tunnel a port or unix socket to your host.
 
-        :param remote_tunnel_port: Port on the remote host to tunnel through ssh
+        :param remote_target: Port or unix socket path on the remote host to tunnel through ssh
         :param ssh_host: ssh remote host address
         :param ssh_port: ssh remote host port
         """
-        self._remote_tunnel_port = remote_tunnel_port
+        self._remote_target = remote_target
         self._ssh_host = ssh_host
         self._ssh_port = ssh_port
 
@@ -72,9 +72,14 @@ class SSHLocalTunnel:
                 config=None,  # Do not parse local config
             ) as conn:
                 self._conn = conn
-                # Forward local port 0 (dynamic) to remote 127.0.0.1:remote_tunnel_port
+                # Forward local port 0 (dynamic) to remote target (port or unix socket)
+                if isinstance(self._remote_target, int):
                     self._server = await conn.forward_local_port(
-                    '127.0.0.1', 0, '127.0.0.1', self._remote_tunnel_port
+                        '127.0.0.1', 0, '127.0.0.1', self._remote_target
+                    )
+                else:
+                    self._server = await conn.forward_local_port_to_path(
+                        '127.0.0.1', 0, self._remote_target
                     )
                 self._local_tunnel_port = self._server.get_port()