Ingress Controller on Minikube not routing correctly flask POST request - flask

Question

I have a simple Flask app. It worked fine when I connected to it via port-forwarding to send the HTTP Post request directly to the Service.
from flask import Flask, request
import redis
from rq import Queue
from worker import job_worker
UPLOAD_FOLDER = './uploads/'
app = Flask(__name__)
r = redis.Redis()
q = Queue(connection = r)
#app.route('/', methods=['POST'])
def upload():
scale = int(request.form['scale'])
q.enqueue(job_worker, scale)
return ""
if __name__ == "__main__":
app.run()
I also have a simple index.html file in an nginx container which is served at port 80. It does an ajax POST request to "/upload". Which if you look at the ingress controller, should convert that to a port 5000 request and strip away the "upload"
The flask app gets served at port 5000
Here is the ingress controller:
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
name: emoji-ingress
annotations:
nginx.ingress.kubernetes.io/rewrite-target: /
spec:
rules:
- http:
paths:
- path: /upload
backend:
serviceName: emoji-backend
servicePort: 5000
- path: /
backend:
serviceName: emoji-frontend
servicePort: 80
And for completeness, the emoji-backend service:
apiVersion: v1
kind: Service
metadata:
name: emoji-backend
labels:
app: emoji-backend
tier: backend
spec:
type: LoadBalancer
ports:
- port: 5000
selector:
app: emoji-backend
tier: backend
I get a 502 bad gateway without really any indication except the ingress log does say this:
2019/09/29 21:41:04 [error] 2021#2021: *78651 connect() failed (111: Connection refused) while connecting to upstream, client: 192.168.64.1, server: _,
request: "POST /upload HTTP/2.0", upstream: "http://172.17.0.4:5000/", host: "192.168.64.5", referrer: "https://192.168.64.5/"
"http://172.17.0.4:5000/" is the correct endpoint and port for the emoji-backend service.

Answer 1

Adding the following line fixed it:
app.run(debug=True,host='0.0.0.0',port=5000)
However, it took me a while to figure that out because at first when I tried it my docker image was not updating when I re-deployed.