Add vsock wsgi server

src/waitress/adjustments.py

@@ -17,7 +17,7 @@
 import socket
 import warnings
 
-from .compat import HAS_IPV6, WIN
+from .compat import CPYTHON, HAS_IPV6, LINUX, WIN
 from .proxy_headers import PROXY_HEADERS
 
 truthy = frozenset(("t", "true", "y", "yes", "on", "1"))
@@ -130,6 +130,7 @@ class Adjustments:
         ("asyncore_use_poll", asbool),
         ("unix_socket", str),
         ("unix_socket_perms", asoctal),
+        ("vsock_socket", str),
         ("sockets", as_socket_list),
         ("channel_request_lookahead", int),
         ("server_name", str),
@@ -254,6 +255,9 @@ class Adjustments:
     # Path to a Unix domain socket to use.
     unix_socket_perms = 0o600
 
+    # Path to a vsock socket to use.
+    vsock_socket = None
+
     # The socket options to set on receiving a connection.  It is a list of
     # (level, optname, value) tuples.  TCP_NODELAY disables the Nagle
     # algorithm for writes (Waitress already buffers its writes).
@@ -302,12 +306,27 @@ def __init__(self, **kw):
         if "sockets" in kw and "unix_socket" in kw:
             raise ValueError("unix_socket may not be set if sockets is set")
 
+        if "sockets" in kw and "vsock_socket" in kw:
+            raise ValueError("vsock_socket may not be set if sockets is set")
+
         if "unix_socket" in kw and ("host" in kw or "port" in kw):
             raise ValueError("unix_socket may not be set if host or port is set")
 
         if "unix_socket" in kw and "listen" in kw:
             raise ValueError("unix_socket may not be set if listen is set")
 
+        if "vsock_socket" in kw and not (LINUX and CPYTHON):
+            raise ValueError("vsock_socket is not supported on this platform")
+
+        if "vsock_socket" in kw and ("host" in kw or "port" in kw):
+            raise ValueError("vsock_socket may not be set if host or port is set")
+
+        if "vsock_socket" in kw and "listen" in kw:
+            raise ValueError("vsock_socket may not be set if listen is set")
+
+        if "vsock_socket" in kw and "unix_socket" in kw:
+            raise ValueError("vsock_socket may not be set if unix_socket is set")
+
         if "send_bytes" in kw:
             warnings.warn(
                 "send_bytes will be removed in a future release", DeprecationWarning

src/waitress/compat.py

@@ -6,8 +6,10 @@
 import sys
 import warnings
 
-# True if we are running on Windows
+# Platform detection.
 WIN = platform.system() == "Windows"
+LINUX = platform.system() == "Linux"
+CPYTHON = platform.python_implementation() == "CPython"
 
 MAXINT = sys.maxsize
 HAS_IPV6 = socket.has_ipv6

src/waitress/server.py

@@ -68,6 +68,18 @@ def create_server(
             sockinfo=sockinfo,
         )
 
+    if adj.vsock_socket and hasattr(socket, "AF_VSOCK"):
+        sockinfo = (socket.AF_VSOCK, socket.SOCK_STREAM, None, None)
+        return VsockWSGIServer(
+            application,
+            map,
+            _start,
+            _sock,
+            dispatcher=dispatcher,
+            adj=adj,
+            sockinfo=sockinfo,
+        )
+
     effective_listen = []
     last_serv = None
     if not adj.sockets:
@@ -118,6 +130,20 @@ def create_server(
             effective_listen.append(
                 (last_serv.effective_host, last_serv.effective_port)
             )
+        elif hasattr(socket, "AF_VSOCK") and sock.family == socket.AF_VSOCK:
+            last_serv = VsockWSGIServer(
+                application,
+                map,
+                _start,
+                sock,
+                dispatcher=dispatcher,
+                adj=adj,
+                bind_socket=False,
+                sockinfo=sockinfo,
+            )
+            effective_listen.append(
+                (last_serv.effective_host, last_serv.effective_port)
+            )
 
     # We are running a single server, so we can just return the last server,
     # saves us from having to create one more object
@@ -376,7 +402,6 @@ def set_socket_options(self, conn):
 
 
 if hasattr(socket, "AF_UNIX"):
-
     class UnixWSGIServer(BaseWSGIServer):
         def __init__(
             self,
@@ -415,6 +440,39 @@ def getsockname(self):
         def fix_addr(self, addr):
             return ("localhost", None)
 
+if hasattr(socket, "AF_VSOCK"):
+    class VsockWSGIServer(BaseWSGIServer):
+        def __init__(
+            self,
+            application,
+            map=None,
+            _start=True,  # test shim
+            _sock=None,  # test shim
+            dispatcher=None,  # dispatcher
+            adj=None,  # adjustments
+            sockinfo=None,  # opaque object
+            **kw
+        ):
+            if sockinfo is None:
+                sockinfo = (socket.AF_VSOCK, socket.SOCK_STREAM, None, None)
+
+            super().__init__(
+                application,
+                map=map,
+                _start=_start,
+                _sock=_sock,
+                dispatcher=dispatcher,
+                adj=adj,
+                sockinfo=sockinfo,
+                **kw,
+            )
+
+        def bind_server_socket(self):
+            self.bind(self.adj.vsock_socket)
+
+        def getsockname(self):
+            return ("vsock", self.socket.getsockname())
+
 
 # Compatibility alias.
 WSGIServer = TcpWSGIServer