Kubernetes Nginx Ingress removing part of URL - nginx

Question

I'm deploying a simple app in Kubernetes (on AKS) which is sat behind an Ingress using Nginx, deployed using the Nginx helm chart. I have a problem that for some reason Nginx doesn't seem to be passing on the full URL to the backend service.
For example, my Ingress is setup with the URL of http://app.client.com and a path of /app1g going http://app.client.com/app1 works fine. However if I try to go to http://app.client.com/app1/service1 I just end up at http://app.client.com/app1, it seems to be stripping everything after the path.
My Ingress looks like this:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/rewrite-target: /
creationTimestamp: "2019-04-03T12:44:22Z"
generation: 1
labels:
chart: app-1.1
component: app
hostName: app.client.com
release: app
name: app-ingress
namespace: default
resourceVersion: "1789269"
selfLink: /apis/extensions/v1beta1/namespaces/default/ingresses/app-ingress
uid: 34bb1a1d-560e-11e9-bd46-9a03420914b9
spec:
rules:
- host: app.client.com
http:
paths:
- backend:
serviceName: app-service
servicePort: 8080
path: /app1
tls:
- hosts:
- app.client.com
secretName: app-prod
status:
loadBalancer:
ingress:
- {}
If I port forward to the service and hit that directly it works.

Answer 1

So I found the answer to this. It seems that as of Nginx v0.22.0 you are required to use capture groups to capture any substrings in the request URI. Prior to 0.22.0 using just nginx.ingress.kubernetes.io/rewrite-target: / worked for any substring. Now it does not. I needed to ammend my ingress to use this:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/rewrite-target: /$1
creationTimestamp: "2019-04-03T12:44:22Z"
generation: 1
labels:
chart: app-1.1
component: app
hostName: app.client.com
release: app
name: app-ingress
namespace: default
resourceVersion: "1789269"
selfLink: /apis/extensions/v1beta1/namespaces/default/ingresses/app-ingress
uid: 34bb1a1d-560e-11e9-bd46-9a03420914b9
spec:
rules:
- host: app.client.com
http:
paths:
- backend:
serviceName: app-service
servicePort: 8080
path: /app1/?(.*)
tls:
- hosts:
- app.client.com
secretName: app-prod
status:
loadBalancer:
ingress:
- {}

Answer 2

Removing this line should fix your problem:
nginx.ingress.kubernetes.io/rewrite-target: /
The rewrite target annotation will do exactly what it says: rewrite your request to hit the "/" location. See nginx-ingress docs for rewrite target.