Code is now more in line with Klemen's

Dockerfile

@@ -3,9 +3,8 @@ FROM python:3.8-slim-buster
 WORKDIR /app
 
 COPY requirements.txt requirements.txt
-
 RUN pip3 install -r requirements.txt
 
 COPY . .
 
-CMD ["python3", "-m", "flask", "run", "--host=0.0.0.0"]
+CMD ["python3", "app.py"]

app.py

@@ -6,3 +6,5 @@ app = Flask(__name__)
 def index():
     return "Hello world!!"
 
+if __name__ == "__main__":
+    app.run(host="0.0.0.0", port=5000)