Update traefik ingress docs

Fixes linkerd#1633

Signed-off-by: Chico Venancio <[email protected]>

linkerd.io/content/2.16/tasks/using-ingress.md

@@ -207,89 +207,56 @@ spec:
 
 ## Traefik
 
-Traefik should be meshed with [ingress mode enabled](#ingress-mode), i.e. with
-the `linkerd.io/inject: ingress` annotation rather than the default `enabled`.
+As of version 2.10, Traefik can be meshed normally: it does not require the
+[ingress mode](#ingress-mode) annotation. Previous versions needed ingress
+mode and custom headers.
 
-Instructions differ for 1.x and 2.x versions of Traefik.
+### Traefik with normal mode {#traefik-normal-mode}
 
-### Traefik 1.x {#traefik-1x}
+With traefik versions 2.10 and newer "Kubernetes Service Native Load-Balancing"
+can be set in the Custom Resource called [`IngressRoute`](
+ https://docs.traefik.io/providers/kubernetes-crd/) with the
+`services[n].nativeLB` field.
 
-The simplest way to use Traefik 1.x as an ingress for Linkerd is to configure a
-Kubernetes `Ingress` resource with the
-`ingress.kubernetes.io/custom-request-headers` like this:
+The YAML bellow exemplifies an IngressRoute for `emojivoto` application.
 
 ```yaml
-# apiVersion: networking.k8s.io/v1beta1 # for k8s < v1.19
-apiVersion: networking.k8s.io/v1
-kind: Ingress
+apiVersion: traefik.io/v1alpha1
+kind: IngressRoute
 metadata:
- name: web-ingress
+ creationTimestamp: null
+ name: emojivoto-web-ingress-route
  namespace: emojivoto
- annotations:
- ingress.kubernetes.io/custom-request-headers: l5d-dst-override:web-svc.emojivoto.svc.cluster.local:80
 spec:
- ingressClassName: traefik
- rules:
- - host: example.com
- http:
- paths:
- - path: /
- pathType: Prefix
- backend:
- service:
- name: web-svc
- port:
- number: 80
+ entryPoints: []
+ routes:
+ - kind: Rule
+ match: PathPrefix(`/`)
+ priority: 0
+ services:
+ - kind: Service
+ name: web-svc
+ port: 80
+ nativeLB: true
 ```
 
-The important annotation here is:
+### Traefik with ingress mode {#traefik-ingress-mode}
 
-```yaml
-ingress.kubernetes.io/custom-request-headers: l5d-dst-override:web-svc.emojivoto.svc.cluster.local:80
-```
+Previous versions of Ttraefik needed to use [ingress mode](#ingress-mode),
+i.e. with the `linkerd.io/inject: ingress` annotation rather than
+ the default `enabled`. and Traefik's [`Middleware`](https://docs.traefik.io/middlewares/headers/)
+Custom Resource to add the `l5d-dst-override` header.
 
 Traefik will add a `l5d-dst-override` header to instruct Linkerd what service
 the request is destined for. You'll want to include both the Kubernetes service
 FQDN (`web-svc.emojivoto.svc.cluster.local`) *and* the destination
 `servicePort`.
 
-To test this, you'll want to get the external IP address for your controller. If
-you installed Traefik via Helm, you can get that IP address by running:
-
-```bash
-kubectl get svc --all-namespaces \
- -l app=traefik \
- -o='custom-columns=EXTERNAL-IP:.status.loadBalancer.ingress[0].ip'
-```
-
-You can then use this IP with curl:
-
-```bash
-curl -H "Host: example.com" http://external-ip
-```
-
-{{< note >}}
-This solution won't work if you're using Traefik's service weights as
-Linkerd will always send requests to the service name in `l5d-dst-override`. A
-workaround is to use `traefik.frontend.passHostHeader: "false"` instead.
-{{< /note >}}
-
-### Traefik 2.x {#traefik-2x}
-
-Traefik 2.x adds support for path based request routing with a Custom Resource
-Definition (CRD) called
-[`IngressRoute`](https://docs.traefik.io/providers/kubernetes-crd/).
-
-If you choose to use `IngressRoute` instead of the default Kubernetes `Ingress`
-resource, then you'll also need to use the Traefik's
-[`Middleware`](https://docs.traefik.io/middlewares/headers/) Custom Resource
-Definition to add the `l5d-dst-override` header.
-
-The YAML below uses the Traefik CRDs to produce the same results for the
-`emojivoto` application, as described above.
+The YAML below uses the Traefik custom resources to configure a route and 
+headers for the `emojivoto` application.
 
 ```yaml
-apiVersion: traefik.containo.us/v1alpha1
+apiVersion: traefik.io/v1alpha1
 kind: Middleware
 metadata:
  name: l5d-header-middleware
@@ -299,11 +266,9 @@ spec:
  customRequestHeaders:
  l5d-dst-override: "web-svc.emojivoto.svc.cluster.local:80"
 ---
-apiVersion: traefik.containo.us/v1alpha1
+apiVersion: traefik.io/v1alpha1
 kind: IngressRoute
 metadata:
- annotations:
- kubernetes.io/ingress.class: traefik
  creationTimestamp: null
  name: emojivoto-web-ingress-route
  namespace: emojivoto
@@ -320,6 +285,11 @@ spec:
  name: web-svc
  port: 80
 ```
+{{< note >}}
+This solution won't work if you're using Traefik's service weights as
+Linkerd will always send requests to the service name in `l5d-dst-override`. A
+workaround is to use `traefik.frontend.passHostHeader: "false"` instead.
+{{< /note >}}
 
 ## GCE