kubernates expose service with ingress on a certain port - kubernetes

Question

Hi I have a react docker that uses nginx
with this service
apiVersion: v1
kind: Service
metadata:
labels:
appcluster: ethernial
app: clientweb
visibility: external
name: clientweb-service-ext
spec:
ports:
- port: 80
name: http
selector:
app: clientweb
type: ClusterIp
I want to expose it, I have only 1 Node that is the Master, but the port 80 is already in use by apache running on master node (cannot shutdown it yet)
I want to expose my react app so I can reach it by http://:30000 for example
(I also need to expose other REST apis externally and internally, one hosted on a pod and each one uses port 80)
so how I setup my ingress?
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: clientweb-ingress
spec:
defaultBackend:
service:
name: clientweb
port:
number: 8080
thanks!

Answer 1

You need to expose the ingress controller using a NodePort service on port 30000. Once you do that you can access backend pods exposed via ingress resource using 30000 port. If you are using nginx ingress controller then follow this doc and the NodePort service(taken from the nginx installation docs) would look like below with your desired port 30000 and 30001.
apiVersion: v1
kind: Service
metadata:
labels:
helm.sh/chart: ingress-nginx-2.13.0
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/version: 0.35.0
app.kubernetes.io/managed-by: Helm
app.kubernetes.io/component: controller
name: ingress-nginx-controller
namespace: ingress-nginx
spec:
type: NodePort
ports:
- name: http
port: 80
protocol: TCP
targetPort: http
nodePort: 30000 # Specified nodeport
- name: https
port: 443
protocol: TCP
targetPort: https
nodePort: 30001 # Specified nodeport
selector:
app.kubernetes.io/name: ingress-nginx
app.kubernetes.io/instance: ingress-nginx
app.kubernetes.io/component: controller
In this case you can still continue to have apache on port 80 on the host system.
curl http://NODEIP:30000/<path-in-ingress>
curl https://NODEIP:30001/<path-in-ingress>

Answer 2

First, you need to understand the relationship between Ingress and Ingress Controller. Ingress is just a kind of resources, and it will do nothing except declare the ingress rules. All Ingress rules will need a certain Ingress Controller to implement its rules.
Then you need to deploy an Ingress Controller, typically a deployment(for certain pod) and a service(for external access). You can have a look at Nginx Ingress Controller at https://kubernetes.github.io/ingress-nginx/ and use kubectl or helm to make the deployment. Do not forget to annotate the ingress-class as it will be used later.
After this, you can apply any Ingress to this certain Ingress Controller by adding kubernetes.io/ingress.class: "nginx" annotation to your Ingress. And ingress controller(nginx server) will add your rules to its config, that means your Ingress rules has been applied.
Finally, as your ingress-controller-service has expose it self(LoadBalanceIp or NodePort from port 30000), all traffic to this endpoint will go through your Ingress rules and redirect to the desire service.