Connection refused to GCP LoadBalancer in Kubernetes - kubernetes

Question

When I create a deployment and a service in a Kubernetes Engine in GCP I get connection refused for no apparent reason.
The service creates a Load Balancer in GCP and all corresponding firewall rules are in place (allows traffic to port 80 from 0.0.0.0/0). The underlying service is running fine, when I kubectl exec into the pod and curl localhost:8000/ I get the correct response.
This deployment setting used to work just fine for other images, but yesterday and today I keep getting
curl: (7) Failed to connect to 35.x.x.x port 80: Connection refused
What could be the issue? I tried deleting and recreating the service multiple times, with no luck.
kind: Service
apiVersion: v1
metadata:
name: my-app
spec:
selector:
app: app
type: LoadBalancer
ports:
- protocol: TCP
port: 80
targetPort: 8000
---
apiVersion: apps/v1beta2
kind: Deployment
metadata:
name: my-app
spec:
replicas: 1
selector:
matchLabels:
app: app
template:
metadata:
labels:
app: app
spec:
containers:
- name: my-app
image: gcr.io/myproject/my-app:0.0.1
imagePullPolicy: Always
ports:
- containerPort: 8000

Answer 1

This turned out to be a dumb mistake on my part. The gunicorn server was using a bind to 127.0.0.1 instead of 0.0.0.0, so it wasn't accessible from outside of the pod, but worked when I exec-ed into the pod.
The fix in my case was changing the entrypoint of the Dockerfile to
CMD [ "gunicorn", "server:app", "-b", "0.0.0.0:8000", "-w", "3" ]
rebuilding the image and updating the deployment.

Answer 2

Is the service binding to your pod? What does "kubectl describe svc my-app" say?
Make sure it transfers through to your pod on the correct port? You can also try, assuming you're using an instance on GCP, to curl the IP and port of the pod and make sure it's responding as it should?
ie, kubectl get pods -o wide, will tell you the IP of the pod
does curl ipofpod:8000 work?