Make upgrade server production ready with gunicorn support

upgrade_server/requirements.txt

@@ -1,5 +1,6 @@
 fastapi
 fastapi-offline>=1.5.0
-#uvicorn
+uvicorn[standard]
+gunicorn
 pydantic
 ruamel.yaml

upgrade_server/upgrade_server.py

@@ -7,53 +7,87 @@ __intname__ = "npbackup.upgrade_server.upgrade_server"
 __author__ = "Orsiris de Jong"
 __copyright__ = "Copyright (C) 2023 NetInvent"
 __license__ = "GPL-3.0-only"
-__build__ = "2023020301"
-__version__ = "1.2.0"
+__build__ = "2023020501"
+__version__ = "1.3.0"
 
 
-DEVEL = True
-
 import sys
 import os
+import multiprocessing
+from argparse import ArgumentParser
 from upgrade_server import configuration
+import upgrade_server.api
 from ofunctions.logger_utils import logger_get_logger
 
 
-config_dict = configuration.load_config()
-try:
-    listen = config_dict["http_server"]["listen"]
-except KeyError:
-    listen = None
-try:
-    port = config_dict["http_server"]["port"]
-except KeyError:
-    listen = None
-
-if DEVEL:
-    import uvicorn as server
-
-    server_args = {
-        "workers": 1,
-        "log_level": "debug",
-        "reload": True,
-        "host": listen if listen else "0.0.0.0",
-        "port": port if port else 8080,
-    }
-else:
-    import gunicorn as server
-
-    server_args = {
-        "workers": 8,
-        "reload": False,
-        "host": listen if listen else "0.0.0.0",
-        "port": port if port else 8080,
-    }
-
-logger = logger_get_logger()
-
-if __name__ == "__main__":
+if __name__ == '__main__':
+    config_dict = configuration.load_config()
     try:
-        server.run("upgrade_server.api:app", **server_args)
+        listen = config_dict["http_server"]["listen"]
+    except KeyError:
+        listen = None
+    try:
+        port = config_dict["http_server"]["port"]
+    except KeyError:
+        listen = None
+
+
+    _DEV = os.environ.get("_DEV", False)
+
+
+    parser = ArgumentParser(
+            prog="{} {} - {}".format(__intname__, __copyright__, __license__),
+            description="""NPBackup Upgrade server""",
+        )
+
+    parser.add_argument(
+            "--dev", action="store_true", help="Run with uvicorn"
+        )
+
+    if _DEV:
+        import uvicorn
+        server_args = {
+            "workers": 1,
+            "log_level": "debug",
+            "reload": True,
+            "host": listen if listen else "0.0.0.0",
+            "port": port if port else 8080,
+        }
+    else:
+        import gunicorn.app.base
+
+        class StandaloneApplication(gunicorn.app.base.BaseApplication):
+            """
+            This class supersedes gunicorn's class in order to load config before launching the app
+            """
+            def __init__(self, app, options=None):
+                self.options = options or {}
+                self.application = app
+                super().__init__()
+
+            def load_config(self):
+                config = {key: value for key, value in self.options.items()
+                        if key in self.cfg.settings and value is not None}
+                for key, value in config.items():
+                    self.cfg.set(key.lower(), value)
+
+            def load(self):
+                return self.application
+
+        server_args = {
+            "workers": (multiprocessing.cpu_count() * 2) + 1,
+            "bind": f'{listen}:{port}' if listen else "0.0.0.0:8080",
+            "worker_class": "uvicorn.workers.UvicornWorker"
+        }
+
+
+    logger = logger_get_logger()
+
+    try:
+        if _DEV:
+            uvicorn.run("upgrade_server.api:app", **server_args)
+        else:
+            StandaloneApplication(upgrade_server.api.app, server_args).run()
     except KeyboardInterrupt as exc:
         logger.error("Program interrupted by keyoard: {}".format(exc))
         sys.exit(200)