WebSocket handshake: Unexpected response code: 400 in kubernetes-ingress

As stated in the nginx-ingress documentation, to proxy WebSocket traffic you should use annotation with the name of websocket service. Don't forget to use quotes:

nginx.org/websocket-services: "service1[,service2,...]"

In this example from the documentation, WebSocket is enabled only for one of three services (ws-svc):

apiVersion: extensions/v1beta1kind: Ingressmetadata:  name: cafe-ingress  annotations:    nginx.org/websocket-services: "ws-svc"spec:  rules:  - host: cafe.example.com    http:      paths:      - path: /tea        backend:          serviceName: tea-svc          servicePort: 80      - path: /coffee        backend:          serviceName: coffee-svc          servicePort: 80      - path: /ws        backend:          serviceName: ws-svc          servicePort: 8008

try add annotationnginx.ingress.kubernetes.io/upstream-hash-by: "$arg_token"

https://github.com/kubernetes/ingress-nginx/issues/2097

You want to add the nginx.org/websocket-services annotation to your ingress resource definition. That, in turn, tells nginx to support websockets (which I believe has to do with the Upgrade/Connection headers?).

apiVersion: extensions/v1beta1kind: Ingressmetadata:  name: websocket-producer-cdph  annotations:    nginx.org/websocket-services: "websocket-producer-cdph"spec:  rules:  - host: some.domain.com    http:      paths:      - path: /        backend:          serviceName: websocket-producer-cdph          servicePort: 8183