Flask API keeps returning 404 for GET requests after deploying locally using functions framework

Question

I am new to flask and firebase, and I am trying to develop a social networking app. I am starting with the API for the profile creation, which works perfectly when run it. However, when I deploy it locally (functions-framework --target=run_app --debug) and try to use the entry point I have defined to make get requests, I get a 404 error. My firebase works.

Here's my main.py code containing my APIs

# Required imports

import os
import functions_framework
from flask import Flask, request, json, jsonify
from firebase_admin import credentials, firestore, initialize_app

# Initialize Flask app

flaskapp = Flask(__name__)

# Use credentials to initialize firebase_admin

cred = credentials.Certificate("finalProject.json")
default_app = initialize_app(cred)
db = firestore.client()

# Define the entry point for the cloud function

@functions_framework.http
def run_app(request):
\# Check the request method
    if request.method == 'POST' and 'name' in request.get_json():
\# Call the register_user function
        return register_user()
    elif request.method == 'GET' and 'userId' in request.args:
\# Call the view_user function
        return view_user(request.args.get('userId'))
    elif request.method == 'PATCH' and 'userId' in request.args:
\# Call the edit_user function
        return edit_user(request.args.get('userId'))

    # Endpoints

# Create user Profile

# @flaskapp.route('/profile', methods=\['POST'\])

def register_user():

# handle request

# View user profile

# @flaskapp.route('/profile/\<userId\>', methods=\['GET'\])

def view_user(userId):

# handle request

# Edit user profile

# @flaskapp.route('/profile/\<userId\>', methods=\['PATCH'\])

def edit_user(userId):

# handle request

# Post

# Feed

# Run Flask app

port = int(os.environ.get('PORT', 8080))
if __name__ == '__main__':
    flaskapp.run(threaded=True, host='0.0.0.0', port=port)

And the postman request I am making with the error are in the attached screenshot.

I tried to test in the terminal using curl "http://localhost:8080/?userId=11112022" and got a curl not found error

Answer 1

I think only functions decorated with @functions_framework.http get mapped to an endpoint. To deploy a full Flask app with routing, etc., to a single endpoint, I got this to work:

# Required imports

import os
import functions_framework
from flask import Flask, request, json, jsonify
from firebase_admin import credentials, firestore, initialize_app

# Initialize Flask app

flaskapp = Flask(__name__)

# Use credentials to initialize firebase_admin

# cred = credentials.Certificate("finalProject.json")
# default_app = initialize_app(cred)
# db = firestore.client()

# Define the entry point for the cloud function

@functions_framework.http
def run_app(request):
    with flaskapp.request_context(request.environ):
        return flaskapp.full_dispatch_request()

# Endpoints

# Create user Profile
@flaskapp.route('/profile', methods=['POST'])
def register_user():
    # handle request
    print("register_user")
    return "register_user"

# View user profile
@flaskapp.route('/profile/<userId>', methods=['GET'])
def view_user(userId):
    # handle request
    print("view_user")
    return "view_user"

# Edit user profile
@flaskapp.route('/profile/<userId>', methods=['PATCH'])
def edit_user(userId):
    # handle request
    print("edit_user")
    return "edit_user"

# Run Flask app
port = int(os.environ.get('PORT', 8080))
if __name__ == '__main__':
    flaskapp.run(threaded=True, host='0.0.0.0', port=port)

(I didn't handle query params, but you can do that in your route handlers.)

Then you can access your routes:

% curl "http://localhost:8080/profile/11112022"           
view_user%
% curl "http://localhost:8080/profile/11112022" -X 'PATCH'
edit_user%
% curl "http://localhost:8080/profile" -X 'POST'          
register_user%

Flask experts can weigh in if this is a bad idea for some reason!