[ray_client]: Insert decorators into the real ray module to allow for client mode (#13031)

python/ray/_private/client_mode_hook.py

@@ -0,0 +1,47 @@
+import os
+from contextlib import contextmanager
+
+client_mode_enabled = os.environ.get("RAY_CLIENT_MODE", "0") == "1"
+
+_client_hook_enabled = True
+
+
+def _enable_client_hook(val: bool):
+    global _client_hook_enabled
+    _client_hook_enabled = val
+
+
+def _disable_client_hook():
+    global _client_hook_enabled
+    out = _client_hook_enabled
+    _client_hook_enabled = False
+    return out
+
+
+def _explicitly_enable_client_mode():
+    global client_mode_enabled
+    client_mode_enabled = True
+
+
+@contextmanager
+def disable_client_hook():
+    val = _disable_client_hook()
+    try:
+        yield None
+    finally:
+        _enable_client_hook(val)
+
+
+def client_mode_hook(func):
+    """
+    Decorator for ray module methods to delegate to ray client
+    """
+    from ray.experimental.client import ray
+
+    def wrapper(*args, **kwargs):
+        global _client_hook_enabled
+        if client_mode_enabled and _client_hook_enabled:
+            return getattr(ray, func.__name__)(*args, **kwargs)
+        return func(*args, **kwargs)
+
+    return wrapper