ingress-nginx annotation rewrite compliance with k8s docs

[boazj]

Is this a BUG REPORT or FEATURE REQUEST? (choose one):
FEATURE REQUEST

NGINX Ingress controller version:
0.10.0

What happened:
The Kubernetes documentation of Ingress provide the following example (https://kubernetes.io/docs/concepts/services-networking/ingress/)
and link directly to ingress-nginx documentation (https://github.com/kubernetes/ingress-nginx/blob/master/docs/examples/rewrite/README.md)

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: test-ingress
  annotations:
    **ingress.kubernetes.io**/rewrite-target: /
spec:
  rules:
  - http:
      paths:
      - path: /testpath
        backend:
          serviceName: test
          servicePort: 80

Though in the file ingress-nginx/internal/ingress/annotations/parser/main.go
We have hardcoded annotation prefix AnnotationsPrefix = "nginx.ingress.kubernetes.io"
Though it can be overridden by
annotationsPrefix = flags.String("annotations-prefix", "nginx.ingress.kubernetes.io", Prefix of the ingress annotations.)

IMHO, either the example should change or ingress-nginx should support ingress.kubernetes.io/rewrite-target OOB.
Note #683 and @delacroixe @colemickens comments, I doubt they execute the controller with --annotations-prefix.
What do you guys think?

[aledbf]

@boazj the change in the prefix of the annotations was an specific request here #1436

[aledbf]

@boazj you can change the prefix using a flag the flag --annotations-prefix in the deployment

[aledbf]

Closing. You are more than welcome to open a PR in the docs repo to change the prefix.

[aledbf]

@boazj just in case the annotation ingress.kubernetes.io/rewrite-target was created in this repository and landed in the docs giving the impression it was supported by all the ingress controllers.