Modify kube-flannel.yaml to use rbac.authorization.k8s.io/v1

This commit modifies Documentation/kube-flannel.yaml to use
ClusterRole & ClusterRoleBinding of 'rbac.authorization.k8s.io/v1'.

Before this commit, 'rbac.authorization.k8s.io/v1beta1' is used at
kube-flannel.yaml. However, from Kubernetes v1.17, this v1beta1
version is deprecated and 'rbac.authorization.k8s.io/v1' becomes GA.

At the time of writing this commit, latest Kubernets version is v1.19.
So, according to Kubernetes support policy, only v1.19, v1.18 & v1.17
are supported and it's safe to use 'rbac.authorization.k8s.io/v1' now.

This commit also modifies docs to mention this change.

Documentation/kube-flannel.yml

@@ -47,7 +47,7 @@ spec:
     rule: 'RunAsAny'
 ---
 kind: ClusterRole
-apiVersion: rbac.authorization.k8s.io/v1beta1
+apiVersion: rbac.authorization.k8s.io/v1
 metadata:
   name: flannel
 rules:
@@ -76,7 +76,7 @@ rules:
       - patch
 ---
 kind: ClusterRoleBinding
-apiVersion: rbac.authorization.k8s.io/v1beta1
+apiVersion: rbac.authorization.k8s.io/v1
 metadata:
   name: flannel
 roleRef:

Documentation/kubernetes.md

@@ -22,6 +22,8 @@ When you run pods, they will be allocated IP addresses from the pod network CIDR
 
 `kube-flannel.yaml` has some features that aren't compatible with older versions of Kubernetes, though flanneld itself should work with any version of Kubernetes.
 
+### For Kubernetes v1.6~v1.15
+
 If you see errors saying `found invalid field...` when you try to apply `kube-flannel.yaml` then you can try the "legacy" manifest file
 * `kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/k8s-manifests/kube-flannel-legacy.yml`
 
@@ -31,6 +33,10 @@ This file does not bundle RBAC permissions. If you need those, run
 If you didn't apply the `kube-flannel-rbac.yml` manifest and you need to, you'll see errors in your flanneld logs about failing to connect.
 * `Failed to create SubnetManager: error retrieving pod spec...`
 
+### For Kubernetes v1.16
+
+`kube-flannel.yaml` uses `ClusterRole` & `ClusterRoleBinding` of `rbac.authorization.k8s.io/v1`. When you use Kubernetes v1.16, you should replace `rbac.authorization.k8s.io/v1` to `rbac.authorization.k8s.io/v1beta1` because `rbac.authorization.k8s.io/v1` had become GA from Kubernetes v1.17.
+
 ## The flannel CNI plugin
 
 The flannel CNI plugin can be found in the CNI plugins [repository](https://github.com/containernetworking/plugins). For additional details, see the [README](https://github.com/containernetworking/plugins/tree/master/plugins/meta/flannel)

README.md

@@ -31,7 +31,7 @@ Though not required, it's recommended that flannel uses the Kubernetes API as it
 
 Flannel can be added to any existing Kubernetes cluster though it's simplest to add `flannel` before any pods using the pod network have been started.
 
-For Kubernetes v1.7+
+For Kubernetes v1.17+
 `kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml`
 
 See [Kubernetes](Documentation/kubernetes.md) for more details.