Enable real guest networking and make demos network-first

src/pyro_mcp/vm_guest.py

@@ -5,13 +5,13 @@ from __future__ import annotations
 import json
 import socket
 from dataclasses import dataclass
-from typing import Callable, Protocol
+from typing import Any, Callable, Protocol
 
 
 class SocketLike(Protocol):
     def settimeout(self, timeout: int) -> None: ...
 
-    def connect(self, address: tuple[int, int]) -> None: ...
+    def connect(self, address: Any) -> None: ...
 
     def sendall(self, data: bytes) -> None: ...
 
@@ -38,19 +38,35 @@ class VsockExecClient:
         self._socket_factory = socket_factory or socket.socket
 
     def exec(
-        self, guest_cid: int, port: int, command: str, timeout_seconds: int
+        self,
+        guest_cid: int,
+        port: int,
+        command: str,
+        timeout_seconds: int,
+        *,
+        uds_path: str | None = None,
     ) -> GuestExecResponse:
         request = {
             "command": command,
             "timeout_seconds": timeout_seconds,
         }
         family = getattr(socket, "AF_VSOCK", None)
-        if family is None:
+        if family is not None:
+            sock = self._socket_factory(family, socket.SOCK_STREAM)
+            connect_address: Any = (guest_cid, port)
+        elif uds_path is not None:
+            sock = self._socket_factory(socket.AF_UNIX, socket.SOCK_STREAM)
+            connect_address = uds_path
+        else:
             raise RuntimeError("vsock sockets are not supported on this host Python runtime")
-        sock = self._socket_factory(family, socket.SOCK_STREAM)
         try:
             sock.settimeout(timeout_seconds)
-            sock.connect((guest_cid, port))
+            sock.connect(connect_address)
+            if family is None:
+                sock.sendall(f"CONNECT {port}\n".encode("utf-8"))
+                status = self._recv_line(sock)
+                if not status.startswith("OK "):
+                    raise RuntimeError(f"vsock unix bridge rejected port {port}: {status.strip()}")
             sock.sendall((json.dumps(request) + "\n").encode("utf-8"))
             chunks: list[bytes] = []
             while True:
@@ -70,3 +86,15 @@ class VsockExecClient:
             exit_code=int(payload.get("exit_code", -1)),
             duration_ms=int(payload.get("duration_ms", 0)),
         )
+
+    @staticmethod
+    def _recv_line(sock: SocketLike) -> str:
+        chunks: list[bytes] = []
+        while True:
+            data = sock.recv(1)
+            if data == b"":
+                break
+            chunks.append(data)
+            if data == b"\n":
+                break
+        return b"".join(chunks).decode("utf-8", errors="replace")