feat: migrate to Flask

Dockerfile

@@ -8,9 +8,9 @@ WORKDIR /app
 
 COPY requirements.txt app.py apt_info.py ./
 
-RUN pip install -r requirements.txt \
+RUN pip install --no-cache-dir --upgrade -r requirements.txt \
     && rm requirements.txt
 
 EXPOSE 8000
 
-CMD ["uvicorn", "app:app", "--host", "0.0.0.0", "--no-access-log"]
+CMD ["gunicorn", "app:app", "-b", "0.0.0.0"]

app.py

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

requirements.txt

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