Nginx Redirection of Jenkins on Kubernetes - jenkins

Question

I am trying to deploy Jenkins on Kubernetes. I have deployed it with ClusterIP along with Nginx Ingress Controller on AKS.
When I access the IP of the Ingress-Controller, the Jenkins login URL (http://ExternalIP/login?from=%2F) comes up. However the UI of the Jenkins page isn't coming up and there is a some sort of redirection happening and keeps growing (http://ExternalIP/login?from=%2F%3Ffrom%3D%252F%253Ffrom%253D%25252F%25253F). I am very new to Ingress controller and annotations. I am not able to figure on what's causing this redirection.
Below are my configuration files. Can anyone please help on what's going wrong ?
ClusterIP-Service.yml
kind: Service
apiVersion: v1
metadata:
name: jenkins-nodeport-svc
namespace: jenkins
labels:
env: poc
app: myapp_jenkins
spec:
ports:
- name: "http"
port: 80
targetPort: 8080
type: ClusterIP
selector:
app: myapp_jenkins
Ingress.yml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: jenkins-ingress
namespace: jenkins
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/ssl-redirect: "false"
nginx.ingress.kubernetes.io/rewrite-target: /$2
nginx.ingress.kubernetes.io/backend-protocol: "HTTP"
nginx.ingress.kubernetes.io/cors-allow-credentials: "true"
nginx.ingress.kubernetes.io/cors-allow-headers: Authorization, origin, accept
nginx.ingress.kubernetes.io/cors-allow-methods: GET, OPTIONS
nginx.ingress.kubernetes.io/enable-cors: "true"
spec:
rules:
- http:
paths:
- backend:
serviceName: jenkins-nodeport-svc
servicePort: 80
path: /(.*)

Answer 1

There's something in your ingress:
path: /(.*)
is a regular expression with a single capturing group that match everything. For example with following url: http://ExternalIP/login?from=myurl your capturing group $1 (the first and only one) would match login?from/myurl.
Now the problem is that nginx.ingress.kubernetes.io/rewrite-target: /$2 annotation is rewriting your url with a non existing capturing group.
You don't need rewriting, you just need to plain forward every request to the service.
Here you can find Rewrite Examples if you interested on it.
But in your case you can set:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: jenkins-ingress
namespace: jenkins
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/ssl-redirect: "false"
nginx.ingress.kubernetes.io/backend-protocol: "HTTP"
nginx.ingress.kubernetes.io/cors-allow-credentials: "true"
nginx.ingress.kubernetes.io/cors-allow-headers: Authorization, origin, accept
nginx.ingress.kubernetes.io/cors-allow-methods: GET, OPTIONS
nginx.ingress.kubernetes.io/enable-cors: "true"
spec:
rules:
- http:
paths:
- backend:
serviceName: jenkins-nodeport-svc
servicePort: 80
path: /
and you're good to go.