Routing Requests With Flask, With Extra Authentication Headers

This article provides a step-by-step guide on how to set up a Flask application with Gunicorn, implement extra authentication headers support, enable both GET and POST HTTP methods, and create a response chunk generation function.

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Run the following like:

pip3 install gunicorn
gunicorn --bind localhost:8001 <file_name_without_extension>:app

import argparse
import requests
from flask import Flask, Response, request
import json
parser = argparse.ArgumentParser(description='Argument Parser with Default Parameters')
parser.add_argument('--source_port', type=int, default=8000, help='Source Port Number')
args, _ = parser.parse_known_args()
print("Source Port:", args.source_port)
source_port = args.source_port
app = Flask(__name__)
sess = requests.Session()
AUTH_TOKEN = "auth_token"
AUTH_HEADER_KEY = "Auth"
GET = "GET"
POST = "POST"
ALLOWED_METHODS = [GET, POST]
@app.route('/', defaults={'path': ''}, methods=ALLOWED_METHODS)
@app.route('/<path:path>', methods=ALLOWED_METHODS)
def chat_completions(path):
url = f'http://localhost:{source_port}{request.full_path}'
# full path is prefixed with /
request_headers = dict(request.headers)
auth = request_headers.get(AUTH_HEADER_KEY, None)
if auth != AUTH_TOKEN:
return Response(json.dumps({"state": "unauthorized", "message": "Unauthorized access"}), status = 401)
no_auth_headers = {k:v for k,v in request_headers.items() if k !=AUTH_HEADER_KEY}
if request.method == GET:
response = sess.get(url, stream=True, headers=no_auth_headers)
else:
response = sess.post(url, stream=True, headers=no_auth_headers, data=request.data, files=request.files, json=request.json)
# form is not accepted.
# response = sess.post(url, stream=True, headers=no_auth_headers, data=request.data, form=request.form, files=request.files, json=request.json)
def generate():
for chunk in response.iter_content(chunk_size=1024):
yield chunk
return Response(generate(), content_type=response.headers['content-type'], headers = dict(response.headers))
if __name__ == '__main__':
app.run()