Use "connect":{...} and "listen":{...} to indicate direction of connection in debug configuration.

src/debugpy/adapter/clients.py

@@ -284,10 +284,43 @@ class Client(components.Component):
         if self.session.no_debug:
             raise request.isnt_valid('"noDebug" is not supported for "attach"')
 
-        listen = request("listen", False)
+        host = request("host", unicode, optional=True)
-        if listen:
+        port = request("port", int, optional=True)
-            host = request("host", "127.0.0.1")
+        listen = request("listen", dict, optional=True)
-            port = request("port", int)
+        connect = request("connect", dict, optional=True)
+        pid = request("processId", (int, unicode), optional=True)
+        sub_pid = request("subProcessId", int, optional=True)
+
+        if host != () or port != ():
+            if listen != ():
+                raise request.isnt_valid(
+                    '"listen" and "host"/"port" are mutually exclusive'
+                )
+            if connect != ():
+                raise request.isnt_valid(
+                    '"connect" and "host"/"port" are mutually exclusive'
+                )
+        if listen != ():
+            if connect != ():
+                raise request.isnt_valid(
+                    '"listen" and "connect" are mutually exclusive'
+                )
+            if pid != ():
+                raise request.isnt_valid(
+                    '"listen" and "processId" are mutually exclusive'
+                )
+            if sub_pid != ():
+                raise request.isnt_valid(
+                    '"listen" and "subProcessId" are mutually exclusive'
+                )
+        if pid != () and sub_pid != ():
+            raise request.isnt_valid(
+                '"processId" and "subProcessId" are mutually exclusive'
+            )
+
+        if listen != ():
+            host = listen("host", "127.0.0.1")
+            port = listen("port", int)
             adapter.access_token = None
             host, port = servers.serve(host, port)
         else:
@@ -303,30 +336,22 @@ class Client(components.Component):
         # in response to a "debugpyAttach" event. If so, the debug server should be
         # connected already, and thus the wait timeout is zero.
         #
-        # If neither is specified, and "listen" is true, this is attach-by-socket
+        # If "listen" is specified, this is attach-by-socket with the server expected
-        # with the server expected to connect to the adapter via debugpy.connect(). There
+        # to connect to the adapter via debugpy.connect(). There is no PID known in
-        # is no PID known in advance, so just wait until the first server connection
+        # advance, so just wait until the first server connection indefinitely, with
-        # indefinitely, with no timeout.
+        # no timeout.
         #
-        # If neither is specified, and "listen" is false, this is attach-by-socket
+        # If "connect" is specified, this is attach-by-socket in which the server has
-        # in which the server has spawned the adapter via debugpy.listen(). There
+        # spawned the adapter via debugpy.listen(). There is no PID known to the client
-        # is no PID known to the client in advance, but the server connection should be
+        # in advance, but the server connection should be either be there already, or
-        # either be there already, or the server should be connecting shortly, so there
+        # the server should be connecting shortly, so there must be a timeout.
-        # must be a timeout.
         #
         # In the last two cases, if there's more than one server connection already,
         # this is a multiprocess re-attach. The client doesn't know the PID, so we just
         # connect it to the oldest server connection that we have - in most cases, it
         # will be the one for the root debuggee process, but if it has exited already,
         # it will be some subprocess.
-
-        pid = request("processId", (int, unicode), optional=True)
-        sub_pid = request("subProcessId", int, optional=True)
         if pid != ():
-            if sub_pid != ():
-                raise request.isnt_valid(
-                    '"processId" and "subProcessId" are mutually exclusive'
-                )
             if not isinstance(pid, int):
                 try:
                     pid = int(pid)
@@ -339,7 +364,7 @@ class Client(components.Component):
         else:
             if sub_pid == ():
                 pred = lambda conn: True
-                timeout = None if listen else 10
+                timeout = 10 if listen == () else None
             else:
                 pred = lambda conn: conn.pid == sub_pid
                 timeout = 0
@@ -447,16 +472,21 @@ class Client(components.Component):
             self._known_subprocesses.add(conn)
 
         body.pop("processId", None)
-        if body.pop("listen", False):
+        body.pop("listen", None)
-            body.pop("host", None)
-            body.pop("port", None)
         body["name"] = fmt("Subprocess {0}", conn.pid)
         body["request"] = "attach"
         body["subProcessId"] = conn.pid
-        if "host" not in body:
+
-            body["host"] = "127.0.0.1"
+        host = body.pop("host", None)
-        if "port" not in body:
+        port = body.pop("port", None)
-            _, body["port"] = listener.getsockname()
+        if "connect" not in body:
+            body["connect"] = {}
+        if "host" not in body["connect"]:
+            body["connect"]["host"] = host if host is not None else "127.0.0.1"
+        if "port" not in body["connect"]:
+            if port is None:
+                _, port = listener.getsockname()
+            body["connect"]["port"] = port
 
         self.channel.send_event("debugpyAttach", body)
 

tests/debug/config.py

@@ -63,9 +63,8 @@ class DebugConfig(collections.MutableMapping):
         "waitOnNormalExit": False,
         "waitOnAbnormalExit": False,
         # Attach by socket
-        "host": (),
+        "listen": (),
-        "port": (),
+        "connect": (),
-        "listen": False,
         # Attach by PID
         "processId": (),
     }

tests/debug/runners.py

@@ -215,8 +215,9 @@ def attach_connect(session, target, method, cwd=None, wait=True, log_dir=None):
     assert method in ("api", "cli")
 
     config = _attach_common_config(session, target, cwd)
-    config["host"] = host = attach_connect.host
+    config["connect"] = {}
-    config["port"] = port = attach_connect.port
+    config["connect"]["host"] = host = attach_connect.host
+    config["connect"]["port"] = port = attach_connect.port
 
     if method == "cli":
         args = [
@@ -267,9 +268,9 @@ def attach_listen(session, target, method, cwd=None, log_dir=None):
     assert method in ("api", "cli")
 
     config = _attach_common_config(session, target, cwd)
-    config["listen"] = True
+    config["listen"] = {}
-    config["host"] = host = attach_listen.host
+    config["listen"]["host"] = host = attach_listen.host
-    config["port"] = port = attach_listen.port
+    config["listen"]["port"] = port = attach_listen.port
 
     if method == "cli":
         args = [

tests/debug/session.py

@@ -432,8 +432,8 @@ class Session(object):
         config = self.config
         request = config.get("request", None)
         if request == "attach":
-            host = config["host"]
+            host = config["connect"]["host"]
-            port = config["port"]
+            port = config["connect"]["port"]
             self.connect_to_adapter((host, port))
             return self.request_attach()
         else:

tests/debugpy/test_attach.py

@@ -54,7 +54,7 @@ def test_attach_api(pyfile, target, wait_for_client, is_client_connected, stop_m
 
     with debug.Session() as session:
         host, port = runners.attach_connect.host, runners.attach_connect.port
-        session.config.update({"host": host, "port": port})
+        session.config.update({"connect": {"host": host, "port": port}})
 
         backchannel = session.open_backchannel()
         session.spawn_debuggee(
@@ -128,9 +128,9 @@ def test_reattach(pyfile, target, run):
 
     with debug.Session() as session2:
         session2.config.update(session1.config)
-        if "host" in session2.config:
+        if "connect" in session2.config:
             session2.connect_to_adapter(
-                (session2.config["host"], session2.config["port"])
+                (session2.config["connect"]["host"], session2.config["connect"]["port"])
             )
 
         with session2.request_attach():

tests/debugpy/test_multiproc.py

@@ -109,8 +109,10 @@ def test_multiprocessing(pyfile, target, run, start_method):
                 "name": some.str,
                 "request": "attach",
                 "subProcessId": some.int,
-                "host": some.str,
+                "connect": {
-                "port": some.int,
+                    "host": some.str,
+                    "port": some.int,
+                }
             }
         )
 
@@ -129,8 +131,10 @@ def test_multiprocessing(pyfile, target, run, start_method):
                     "name": some.str,
                     "request": "attach",
                     "subProcessId": some.int,
-                    "host": some.str,
+                    "connect": {
-                    "port": some.int,
+                        "host": some.str,
+                        "port": some.int,
+                    }
                 }
             )
 
@@ -191,8 +195,10 @@ def test_subprocess(pyfile, target, run):
                 "name": some.str,
                 "request": "attach",
                 "subProcessId": some.int,
-                "host": some.str,
+                "connect": {
-                "port": some.int,
+                    "host": some.str,
+                    "port": some.int,
+                }
             }
         )