How to handle kubernetes Ingress Rule with two backends - nginx

Question

I try to run my web application with two backend containers.
/ should be routed to the frontend container
everything starting with /backend/ should go to the backend container.
So fare, so good, but now the css & js files from the /backend are not loaded because the files are referenced in the HTML file like "/bundles/css/style.css" and now ingress controller route this request to the frontend container instead of to the backend.
How can I fix this issue?
Can I fix that with a smart Ingress rule?
Do I need to update the app root of the backend container?
Here my Ingress resource
apiVersion: networking.k8s.io/v1 # for versions before 1.14 use extensions/v1beta1
kind: Ingress
metadata:
name: example
namespace: example
annotations:
kubernetes.io/ingress.class: "nginx"
cert-manager.io/cluster-issuer: "letsencrypt-prod"
nginx.ingress.kubernetes.io/rewrite-target: /$2
spec:
tls:
- hosts:
- www.example.ch
secretName: tls-example.ch
rules:
- host: www.example.ch
http:
paths:
- path: /backend(/|$)(.*)
pathType: Prefix
backend:
service:
name: example-backend-svc
port:
number: 8081
- path: /
pathType: Prefix
backend:
service:
name: example-frontend-svc
port:
number: 8080

Answer 1

You can add another path if all files are located in /bundles/* path.
I have given an example manifest file below.
apiVersion: networking.k8s.io/v1 # for versions before 1.14 use extensions/v1beta1
kind: Ingress
metadata:
name: example
namespace: example
annotations:
kubernetes.io/ingress.class: "nginx"
cert-manager.io/cluster-issuer: "letsencrypt-prod"
nginx.ingress.kubernetes.io/rewrite-target: /$2
spec:
tls:
- hosts:
- www.example.ch
secretName: tls-example.ch
rules:
- host: www.example.ch
http:
paths:
- path: /backend(/|$)(.*)
pathType: Prefix
backend:
service:
name: example-backend-svc
port:
number: 8081
- path: /bundles
pathType: Prefix
backend:
service:
name: example-backend-svc
port:
number: 8081
- path: /
pathType: Prefix
backend:
service:
name: example-frontend-svc
port:
number: 8080