Improve Kubernetes support documentation

Co-authored-by: Kevin Pollet <pollet.kevin@gmail.com>

docs/content/deprecation/features.md

@@ -6,6 +6,7 @@ This page is maintained and updated periodically to reflect our roadmap and any
 |----------------------------------------------------------------------------------------------------------------------|------------|----------------|---------|
 | [Kubernetes CRDs API Version `traefik.io/v1alpha1`](#kubernetes-crds-api-version-traefikiov1alpha1)                  | N/A        | N/A            | 3.0     |
 | [Kubernetes Ingress API Version `networking.k8s.io/v1beta1`](#kubernetes-ingress-api-version-networkingk8siov1beta1) | N/A        | N/A            | 3.0     |
+| [CRD API Version `apiextensions.k8s.io/v1beta1`](#kubernetes-ingress-api-version-networkingk8siov1beta1)             | N/A        | N/A            | 3.0     |
 
 ## Impact
 
@@ -16,3 +17,7 @@ The newly introduced Kubernetes CRD API Version `traefik.io/v1alpha1` will subse
 ### Kubernetes Ingress API Version `networking.k8s.io/v1beta1`
 
 The Kubernetes Ingress API Version `networking.k8s.io/v1beta1` is removed in v3. Please use the API Group `networking.k8s.io/v1` instead.
+
+### Traefik CRD API Version `apiextensions.k8s.io/v1beta1`
+
+The Traefik CRD API Version `apiextensions.k8s.io/v1beta1` is removed in v3. Please use the API Group `apiextensions.k8s.io/v1` instead.

docs/content/includes/kubernetes-requirements.md

@@ -0,0 +1,3 @@
+Traefik follows the [Kubernetes support policy](https://kubernetes.io/releases/version-skew-policy/#supported-versions),
+and supports at least the latest three minor versions of Kubernetes.
+General functionality cannot be guaranteed for versions older than that.

docs/content/middlewares/http/overview.md

@@ -26,19 +26,6 @@ whoami:
 
 ```yaml tab="Kubernetes IngressRoute"
 # As a Kubernetes Traefik IngressRoute
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: middlewares.traefik.io
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: Middleware
-    plural: middlewares
-    singular: middleware
-  scope: Namespaced
-
 ---
 apiVersion: traefik.io/v1alpha1
 kind: Middleware

docs/content/middlewares/tcp/overview.md

@@ -26,19 +26,6 @@ whoami:
 
 ```yaml tab="Kubernetes IngressRoute"
 # As a Kubernetes Traefik IngressRoute
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: middlewaretcps.traefik.io
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: MiddlewareTCP
-    plural: middlewaretcps
-    singular: middlewaretcp
-  scope: Namespaced
-
 ---
 apiVersion: traefik.io/v1alpha1
 kind: MiddlewareTCP

docs/content/migration/v2-to-v3.md

@@ -97,7 +97,12 @@ In v3, the provider Docker has been split into 2 providers:
 
 ### Kubernetes Ingress API Group `networking.k8s.io/v1beta1`
 
-As v3 is targeting support for Kubernetes v1.23+,
+In v3, the Kubernetes Ingress API Group `networking.k8s.io/v1beta1` ([removed since Kubernetes v1.22](https://kubernetes.io/docs/reference/using-api/deprecation-guide/#ingress-v122)) support has been removed.
-the Kubernetes Ingress API Group `networking.k8s.io/v1beta1` ([removed since Kubernetes v1.22](https://kubernetes.io/docs/reference/using-api/deprecation-guide/#ingress-v122)) support has been removed.
 
 Please use the API Group `networking.k8s.io/v1` instead.
+
+### Traefik CRD API Version `apiextensions.k8s.io/v1beta1`
+
+In v3, the Traefik CRD API Version `apiextensions.k8s.io/v1beta1` ([removed since Kubernetes v1.22](https://kubernetes.io/docs/reference/using-api/deprecation-guide/#customresourcedefinition-v122)) support has been removed.
+
+Please use the CRD definition with the API Version `apiextensions.k8s.io/v1` instead.

docs/content/providers/kubernetes-crd.md

@@ -14,7 +14,9 @@ However, as the community expressed the need to benefit from Traefik features wi
 the Traefik engineering team developed a [Custom Resource Definition](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/)
 (CRD) for an IngressRoute type, defined below, in order to provide a better way to configure access to a Kubernetes cluster.
 
-## Configuration Requirements
+## Requirements
+
+{!kubernetes-requirements.md!}
 
 !!! tip "All Steps for a Successful Deployment"
 
@@ -25,12 +27,6 @@ the Traefik engineering team developed a [Custom Resource Definition](https://ku
         * Apply the needed kubernetesCRD provider [configuration](#provider-configuration)
     * Add all necessary Traefik custom [resources](../reference/dynamic-configuration/kubernetes-crd.md#resources)
 
-!!! warning "Deprecated apiextensions.k8s.io/v1beta1 CRD"
-
-    The `apiextensions.k8s.io/v1beta1` CustomResourceDefinition is deprecated in Kubernetes `v1.16+` and will be removed in `v1.22+`.
-    
-    For Kubernetes `v1.16+`, please use the Traefik `apiextensions.k8s.io/v1` CRDs instead.
-
 !!! example "Installing Resource Definition and RBAC"
 
     ```bash

docs/content/providers/kubernetes-gateway.md

@@ -41,7 +41,9 @@ This provider is proposed as an experimental feature and partially supports the
     --experimental.kubernetesgateway=true --providers.kubernetesgateway=true #...
     ```
 
-## Configuration Requirements
+## Requirements
+
+{!kubernetes-requirements.md!}
 
 !!! tip "All Steps for a Successful Deployment"
 

docs/content/providers/kubernetes-ingress.md

@@ -13,7 +13,7 @@ it manages access to cluster services by supporting the [Ingress](https://kubern
 
 ## Requirements
 
-Traefik supports `1.23+` Kubernetes clusters.
+{!kubernetes-requirements.md!}
 
 ## Routing Configuration
 

docs/content/reference/dynamic-configuration/kubernetes-crd-definition-v1beta1.yml

@@ -1,133 +0,0 @@
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: ingressroutes.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: IngressRoute
-    plural: ingressroutes
-    singular: ingressroute
-  scope: Namespaced
-
----
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: middlewares.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: Middleware
-    plural: middlewares
-    singular: middleware
-  scope: Namespaced
-
----
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: middlewaretcps.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: MiddlewareTCP
-    plural: middlewaretcps
-    singular: middlewaretcp
-  scope: Namespaced
-
----
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: ingressroutetcps.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: IngressRouteTCP
-    plural: ingressroutetcps
-    singular: ingressroutetcp
-  scope: Namespaced
-
----
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: ingressrouteudps.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: IngressRouteUDP
-    plural: ingressrouteudps
-    singular: ingressrouteudp
-  scope: Namespaced
-
----
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: tlsoptions.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: TLSOption
-    plural: tlsoptions
-    singular: tlsoption
-  scope: Namespaced
-
----
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: tlsstores.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: TLSStore
-    plural: tlsstores
-    singular: tlsstore
-  scope: Namespaced
-
----
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: traefikservices.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: TraefikService
-    plural: traefikservices
-    singular: traefikservice
-  scope: Namespaced
-
----
-apiVersion: apiextensions.k8s.io/v1beta1
-kind: CustomResourceDefinition
-metadata:
-  name: serverstransports.traefik.io
-
-spec:
-  group: traefik.io
-  version: v1alpha1
-  names:
-    kind: ServersTransport
-    plural: serverstransports
-    singular: serverstransport
-  scope: Namespaced

docs/content/reference/dynamic-configuration/kubernetes-crd.md

@@ -8,22 +8,12 @@ description: "Learn about the definitions, resources, and RBAC of dynamic config
 Dynamic configuration with Kubernetes Custom Resource
 {: .subtitle }
 
-!!! warning "Deprecated apiextensions.k8s.io/v1beta1 CRD"
-
-    The `apiextensions.k8s.io/v1beta1` CustomResourceDefinition is deprecated in Kubernetes `v1.16+` and will be removed in `v1.22+`.
-
-    For Kubernetes `v1.16+`, please use the Traefik `apiextensions.k8s.io/v1` CRDs instead.
-
 ## Definitions
 
 ```yaml tab="apiextensions.k8s.io/v1 (Kubernetes v1.16+)"
 --8<-- "content/reference/dynamic-configuration/kubernetes-crd-definition-v1.yml"
 ```
 
-```yaml tab="apiextensions.k8s.io/v1beta1 (Deprecated)"
---8<-- "content/reference/dynamic-configuration/kubernetes-crd-definition-v1beta1.yml"
-```
-
 ## Resources
 
 ```yaml

docs/content/routing/providers/kubernetes-crd.md

@@ -290,7 +290,7 @@ The Kubernetes Ingress Controller, The Custom Resource Way.
 ### Custom Resource Definition (CRD)
 
 * You can find an exhaustive list, generated from Traefik's source code, of the custom resources and their attributes in [the reference page](../../reference/dynamic-configuration/kubernetes-crd.md).
-* Validate that [the prerequisites](../../providers/kubernetes-crd.md#configuration-requirements) are fulfilled before using the Traefik custom resources.
+* Validate that [the prerequisites](../../providers/kubernetes-crd.md#requirements) are fulfilled before using the Traefik custom resources.
 * Traefik CRDs are building blocks that you can assemble according to your needs.
     
 You can find an excerpt of the available custom resources in the table below:

docs/content/routing/providers/kubernetes-gateway.md

@@ -34,7 +34,7 @@ The Kubernetes Gateway API, The Experimental Way. {: .subtitle }
 * You can find an exhaustive list, of the custom resources and their attributes in
   [the reference page](../../reference/dynamic-configuration/kubernetes-gateway.md) or in the Kubernetes
   Sigs `Gateway API` [repository](https://github.com/kubernetes-sigs/gateway-api).
-* Validate that [the prerequisites](../../providers/kubernetes-gateway.md#configuration-requirements) are fulfilled
+* Validate that [the prerequisites](../../providers/kubernetes-gateway.md#requirements) are fulfilled
   before using the Traefik Kubernetes Gateway Provider.
 
 You can find an excerpt of the supported Kubernetes Gateway API resources in the table below: