MERN app in microk8s kubernetes with ingress, page does not display - node.js

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