[IMPL] - Custom backend server and improved configuration capabilities

reflex/config.py

@@ -36,7 +36,7 @@
 
 from reflex_cli.constants.hosting import Hosting
 
-from reflex import constants
+from reflex import constants, server
 from reflex.base import Base
 from reflex.utils import console
 
@@ -649,7 +649,7 @@ class Config:
     # Tailwind config.
     tailwind: Optional[Dict[str, Any]] = {"plugins": ["@tailwindcss/typography"]}
 
-    # Timeout when launching the gunicorn server. TODO(rename this to backend_timeout?)
+    # Timeout when launching the gunicorn server. TODO(rename this to backend_timeout?); deprecated
     timeout: int = 120
 
     # Whether to enable or disable nextJS gzip compression.
@@ -666,16 +666,16 @@ class Config:
     # The hosting service frontend URL.
     cp_web_url: str = Hosting.HOSTING_SERVICE_UI
 
-    # The worker class used in production mode
+    # The worker class used in production mode; deprecated
     gunicorn_worker_class: str = "uvicorn.workers.UvicornH11Worker"
 
-    # Number of gunicorn workers from user
+    # Number of gunicorn workers from user; deprecated
     gunicorn_workers: Optional[int] = None
 
-    # Number of requests before a worker is restarted
+    # Number of requests before a worker is restarted; deprecated
     gunicorn_max_requests: int = 100
 
-    # Variance limit for max requests; gunicorn only
+    # Variance limit for max requests; gunicorn only; deprecated
     gunicorn_max_requests_jitter: int = 25
 
     # Indicate which type of state manager to use
@@ -696,6 +696,14 @@ class Config:
     # Path to file containing key-values pairs to override in the environment; Dotenv format.
     env_file: Optional[str] = None
 
+    # Custom Backend Server
+    backend_server_prod: server.CustomBackendServer = server.GunicornBackendServer(
+        threads=2, workers=4, max_requests=100, max_requests_jitter=25, timeout=120
+    )
+    backend_server_dev: server.CustomBackendServer = server.UvicornBackendServer(
+        workers=1,
+    )
+
     def __init__(self, *args, **kwargs):
         """Initialize the config values.
 
@@ -726,6 +734,24 @@ def __init__(self, *args, **kwargs):
                 "REDIS_URL is required when using the redis state manager."
             )
 
+        if any(
+            getattr(self.get_fields().get(key, None), "default", None)
+            == self.get_value(key)
+            for key in (
+                "timeout",
+                "gunicorn_worker_class",
+                "gunicorn_workers",
+                "gunicorn_max_requests",
+                "gunicorn_max_requests_jitter",
+            )
+        ):
+            console.deprecate(
+                'The following reflex configuration fields are obsolete: "timeout", "gunicorn_worker_class", "gunicorn_workers", "gunicorn_max_requests", "gunicorn_max_requests_jitter"\nplease update your configuration.',
+                reason="Use `config.backend_server_dev` or `config.backend_server_prod` instead in your `rxconfig.py`.",
+                deprecation_version="0.7.x",
+                removal_version="x.x.x",
+            )
+
     @property
     def module(self) -> str:
         """Get the module name of the app.

reflex/server/__init__.py

@@ -0,0 +1,13 @@
+"""Import every *BackendServer."""
+
+from .base import CustomBackendServer
+from .granian import GranianBackendServer
+from .gunicorn import GunicornBackendServer
+from .uvicorn import UvicornBackendServer
+
+__all__ = [
+    "CustomBackendServer",
+    "GranianBackendServer",
+    "GunicornBackendServer",
+    "UvicornBackendServer",
+]