Remove prefix after match before forwarding request to service - nginx

Question

I have this base url api.example.com
So, ingress-nginx will get the request for api.example.com and it should do follow things.
Forward api.example.com/customer to customer-srv
It doesn't work, it forwards whole mtach to customer-srv i.e. /customer/requested_url
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ingress-service
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/use-regex: "true"
spec:
rules:
- host: api.example.in
http:
paths:
- path: /customer/?(.*)
pathType: Prefix
backend:
service:
name: customer-srv
port:
number: 3000
I tried using rewrite annotation but that doesn't work either however this worked but this is not I want to achieve.
paths:
- path: /?(.*)
pathType: Prefix
backend:
service:
name: customer-srv
port:
number: 3000
For example,
api.example.com/customer should go to http://localhost:3000 not http://localhost:3000/customer

Answer 1

Here is the yaml I used:
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: ingress-service
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
rules:
- host: api.example.in
http:
paths:
- path: /customer/?(.*)
pathType: Prefix
backend:
service:
name: customer-srv
port:
number: 3000
For test purpouses I created an echo server:
kubectl run --image mendhak/http-https-echo customer
And then a service:
kubectl expose po customer --name customer-srv --port 3000 --target-port 80
I checked igress ip:
$ kubectl get ingress
NAME CLASS HOSTS ADDRESS PORTS AGE
ingress-service <none> api.example.in 192.168.39.254 80 3m43s
And I did a curl to check it:
curl 192.168.39.254/customer/asd -H "Host: api.example.in"
{
"path": "/asd",
"headers": {
"host": "api.example.in",
...
}
Notice that the echo server echoed back a path that it received, and sice it received a path that got rewritten from /customer/asd to /asd it shows this exectly path (/asd).
So as you see this does work.