Kubernetes 的Ingress的Rewrite annotations

!!! attention Starting in Version 0.22.0, ingress definitions using the annotation nginx.ingress.kubernetes.io/rewrite-target are not backwards compatible with previous versions. In Version 0.22.0 and beyond, any substrings within the request URI that need to be passed to the rewritten path must explicitly be defined in a capture group.

!!! note Captured groups are saved in numbered placeholders, chronologically, in the form $1, $2 … $n. These placeholders can be used as parameters in the rewrite-target annotation.

Create an Ingress rule with a rewrite annotation:

 echo '
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$2
  name: rewrite
  namespace: default
spec:
  rules:
  - host: rewrite.bar.com
    http:
      paths:
      - path: /something(/|$)(.*)
        pathType: Prefix
        backend:
          service:
            name: http-svc
            port: 
              number: 80
' | kubectl create -f -

In this ingress definition, any characters captured by (.*) will be assigned to the placeholder $2, which is then used as a parameter in the rewrite-target annotation.

For example, the ingress definition above will result in the following rewrites:

rewrite.bar.com/something rewrites to rewrite.bar.com/
rewrite.bar.com/something/ rewrites to rewrite.bar.com/
rewrite.bar.com/something/new rewrites to rewrite.bar.com/new

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-lys
  namespace: d1ad16990e484ab7838f5922e1d4b78d
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: "/$1"
spec:
  rules:
  - host: foo.lys.com
    http:
      paths:
      - path: /test/(.*)$
        pathType: Prefix
        backend:
          service:
            name: lys-test-service
            port:
              number: 8081

https://github.com/kubernetes/ingress-nginx/blob/main/docs/examples/rewrite/README.md