Update Gunicorn for Production (#387)

* add gunicorn and configure Dockerfile

* refactor: replace list with tuple and os.environ for env variables

* fix error

Author: techUdayMungalpara

lessons/231/python-app/Dockerfile

@@ -24,4 +24,11 @@ COPY . /app
 # CMD ["fastapi", "run", "--workers", "2", "main.py"]
 
 # 4 for the second test to achieve full CPU utilization
-CMD ["fastapi", "run", "--workers", "4", "main.py"]
+CMD ["gunicorn", 
+     "-w", "4", 
+     "-k", "uvicorn.workers.UvicornWorker", 
+     "--timeout", "60", 
+     "--graceful-timeout", "60", 
+     "--log-level", "error", 
+     "main:app", 
+     "--bind", "0.0.0.0:8000"]

lessons/231/python-app/db.py

@@ -13,8 +13,8 @@
 
 POSTGRES_URI = POSTGRES_URI = os.environ["POSTGRES_URI"]
 POSTGRES_POOL_SIZE = int(os.environ["POSTGRES_POOL_SIZE"])
-MEMCACHED_HOST = os.environ.get["MEMCACHED_HOST"]
-MEMCACHED_POOL_SIZE = os.environ.get["MEMCACHED_POOL_SIZE"]
+MEMCACHED_HOST = os.environ["MEMCACHED_HOST"]
+MEMCACHED_POOL_SIZE = os.environ["MEMCACHED_POOL_SIZE"]
 
 
 # os.environ.get["MEMCACHED_POOL_SIZE"]

lessons/231/python-app/main.py

@@ -45,7 +45,7 @@ def health():
 
 @app.get("/api/devices", response_class=ORJSONResponse)
 def get_devices():
-    devices = [
+    devices = (
         {
             "id": 1,
             "uuid": "9add349c-c35c-4d32-ab0f-53da1ba40a2a",
@@ -70,7 +70,7 @@ def get_devices():
             "created_at": "2024-08-28T15:18:21.137Z",
             "updated_at": "2024-08-28T15:18:21.137Z",
         },
-    ]
+    )
 
     return devices
 
@@ -144,7 +144,6 @@ async def create_device(
 
     except Exception:
         logger.exception("Unknown error")
-        print(f"Unexpected error during device creation: {str(e)}")
         raise HTTPException(
             status_code=500, detail="An unexpected error occurred while creating device"
         )

lessons/231/python-app/requirements.txt

@@ -8,6 +8,7 @@ dnspython==2.7.0
 email_validator==2.2.0
 fastapi==0.115.6
 fastapi-cli==0.0.6
+gunicorn==23.0.0
 h11==0.14.0
 httpcore==1.0.7
 httptools==0.6.4
@@ -18,6 +19,7 @@ markdown-it-py==3.0.0
 MarkupSafe==3.0.2
 mdurl==0.1.2
 orjson==3.10.12
+packaging==24.2
 prometheus-fastapi-instrumentator==7.0.0
 prometheus_client==0.21.1
 psycopg==3.2.3