MERN app in microk8s kubernetes with ingress, page does not display

Question

I have a Mongo, Express, React Node app that is currently deployed in a microk8s pod. I am trying to setup Ingress for the app. The express server is setup to serve the react with express.static like below

  app.use(express.static('DemoApp/build'));

  app.get('*', function(req, res, next) {
    res.sendFile(path.resolve(__dirname, 'DemoApp', 'build', 'index.html'));
  });

Everything works fine when I navigate to the ip:port of the kubernetes cluster and even everything works fine when I navigate to the FQDN for the ingress host but as soon as I add a path to the ingress then the app only shows a white screen. One note, my kubernetes node and workstations are all running inside an internal private network. I am not trying to expose anything outside of that. I have tried to follow the step provided in this post ( ReactJS app displays whitescreen using Kubernetes Ingress ) but it has not fixed the issue. I have the built in ingress controller enabled for microk8s.

Below is the YAML I am using for ingress that doesnt work

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: demo-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$1
  namespace: default
spec:
  rules:
  - host: apps.sst.com
    http:
      paths:
      - path: /demo(/|$)(.*)
        backend:
          serviceName: mern-demo
          servicePort: 4000

Here is the YAML for ingress that does work

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: demo-ingress
  annotations:
  namespace: default
spec:
  rules:
  - host: apps.sst.com
    http:
      paths:
      - path:
        backend:
          serviceName: mern-demo
          servicePort: 4000

One other note is that my app is using react router. Based on further research I am wondering if this affects things at all.

Any help would be greatly appreciated. Thanks

Answer 1

rewrite-target annotation which was used in your YAML

  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$1

works only for Nginx Ingress . As you are using your default ingress it will not work. You would need to install it manually as it is mentioned here .

Now depends on your env if it's local or cloud you would need to configure MetalLB . For more details you can check this thread .

There was also similar StackOverflow question regarding Nginx Ingress issue on MicroK8s , you can read about it in this SO thread .

However, do you need to use rewrite? You cannot use multiple paths and default backend ? Something like this:

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: my-ingress
spec:
  backend:
    serviceName: hello-world
    servicePort: 60000
  rules:
  - http:
      paths:
      - path: /world
        backend:
          serviceName: hello-world
          servicePort: 60000
      - path: /kube
        backend:
          serviceName: hello-kubernetes
          servicePort: 80