[ray_client]: first draft of documentation (#13216)

python/ray/util/__init__.py

@@ -7,8 +7,20 @@ from ray.util.placement_group import (placement_group, placement_group_table,
                                       remove_placement_group)
 from ray.util import rpdb as pdb
 
+from ray.util.client_connect import connect, disconnect
+
 __all__ = [
-    "ActorPool", "disable_log_once_globally", "enable_periodic_logging",
-    "iter", "log_once", "pdb", "placement_group", "placement_group_table",
-    "remove_placement_group", "inspect_serializability", "collective"
+    "ActorPool",
+    "disable_log_once_globally",
+    "enable_periodic_logging",
+    "iter",
+    "log_once",
+    "pdb",
+    "placement_group",
+    "placement_group_table",
+    "remove_placement_group",
+    "inspect_serializability",
+    "collective",
+    "connect",
+    "disconnect",
 ]

python/ray/util/client/__init__.py

@@ -75,7 +75,7 @@ class RayAPIStub:
         return getattr(self.api, key)
 
     def is_connected(self) -> bool:
-        return self.api is not None
+        return self.client_worker is not None
 
     def init(self, *args, **kwargs):
         if self._server is not None:

python/ray/util/client/server/server.py

@@ -427,7 +427,7 @@ def main():
         "-p", "--port", type=int, default=50051, help="Port to bind to")
     parser.add_argument(
         "--redis-address",
-        required=True,
+        required=False,
         type=str,
         help="Address to use to connect to Ray")
     parser.add_argument(
@@ -437,11 +437,15 @@ def main():
         help="Password for connecting to Redis")
     args = parser.parse_args()
     logging.basicConfig(level="INFO")
-    if args.redis_password:
-        ray.init(
-            address=args.redis_address, _redis_password=args.redis_password)
+    if args.redis_address:
+        if args.redis_password:
+            ray.init(
+                address=args.redis_address,
+                _redis_password=args.redis_password)
+        else:
+            ray.init(address=args.redis_address)
     else:
-        ray.init(address=args.redis_address)
+        ray.init()
     hostport = "%s:%d" % (args.host, args.port)
     logger.info(f"Starting Ray Client server on {hostport}")
     server = serve(hostport)

python/ray/util/client_connect.py

@@ -0,0 +1,31 @@
+from ray.util.client import ray
+
+from ray._private.client_mode_hook import _enable_client_hook
+from ray._private.client_mode_hook import _explicitly_enable_client_mode
+
+from typing import List
+from typing import Tuple
+
+
+def connect(conn_str: str,
+            secure: bool = False,
+            metadata: List[Tuple[str, str]] = None) -> None:
+    if ray.is_connected():
+        raise RuntimeError("Ray Client is already connected. "
+                           "Maybe you called ray.util.connect twice by "
+                           "accident?")
+    # Enable the same hooks that RAY_CLIENT_MODE does, as
+    # calling ray.util.connect() is specifically for using client mode.
+    _enable_client_hook(True)
+    _explicitly_enable_client_mode()
+
+    # TODO(barakmich): https://github.com/ray-project/ray/issues/13274
+    # for supporting things like cert_path, ca_path, etc and creating
+    # the correct metadata
+    return ray.connect(conn_str, secure=secure, metadata=metadata)
+
+
+def disconnect():
+    if not ray.is_connected():
+        raise RuntimeError("Ray Client is currently disconnected.")
+    return ray.disconnect()