feat: revert back to FastAPI

Dockerfile

@@ -13,4 +13,4 @@ RUN pip install --no-cache-dir --upgrade -r requirements.txt \
 
 EXPOSE 8000
 
-CMD ["gunicorn", "app:app", "-b", "0.0.0.0"]
+CMD ["uvicorn", "app:app", "--host", "0.0.0.0", "--no-access-log"]

app.py

@@ -1,13 +1,14 @@
 import os
-from flask import Flask, Response
+from fastapi import FastAPI
+from fastapi.responses import PlainTextResponse
 import apt_info
 
 root_dir = os.environ.get("APT_ROOT_DIR", "/")
 
-app = Flask(__name__)
+app = FastAPI()
 
 
-@app.route("/metrics")
+@app.get("/metrics", response_class=PlainTextResponse)
 def metrics():
     data = apt_info.generate_metrics(root_dir=root_dir)
-    return Response(data, mimetype='text/plain')
+    return data

requirements.txt

@@ -1,4 +1,4 @@
 python-apt @ git+https://salsa.debian.org/apt-team/python-apt.git@2.5.3
 prometheus_client==0.17.1
-Flask==3.0.0
-gunicorn==21.2.0
+fastapi==0.103.2
+uvicorn[standard]==0.23.2