Update Cilium related docs (#18563)

* Extend Cilium CNI plugin description

Mention that it works on top of other CNI plugins due to the CNI
chaining [1].

[1]: http://docs.cilium.io/en/v1.6/gettingstarted/cni-chaining/

Signed-off-by: Martynas Pumputis <m@lambda.lt>

* Update Cilium installation steps for kubeadm

- Use the latest v1.6 Cilium.
- By default, Cilium no longer needs/deploys ETCD store.

Signed-off-by: Martynas Pumputis <m@lambda.lt>

* Update Cilium NetworkPolicy guide

- Update minikube min version requirement.
- Use Cilium v1.6.
- Remove the etcd store bits, as Cilium v1.6 no longer depend on
  it by default.

Signed-off-by: Martynas Pumputis <m@lambda.lt>

* Update Cilium installation steps for kubeadm

- How to run without kube-proxy.

Signed-off-by: Martynas Pumputis <m@lambda.lt>

Co-authored-by: Martynas Pumputis <m@lambda.lt>

content/en/docs/tasks/administer-cluster/network-policy-provider/cilium-network-policy.md

@@ -10,7 +10,7 @@ weight: 20
 {{% capture overview %}}
 This page shows how to use Cilium for NetworkPolicy.
 
-For background on Cilium, read the [Introduction to Cilium](https://cilium.readthedocs.io/en/stable/intro).
+For background on Cilium, read the [Introduction to Cilium](https://docs.cilium.io/en/stable/intro).
 {{% /capture %}}
 
 {{% capture prerequisites %}}
@@ -23,36 +23,45 @@ For background on Cilium, read the [Introduction to Cilium](https://cilium.readt
 ## Deploying Cilium on Minikube for Basic Testing
 
 To get familiar with Cilium easily you can follow the
-[Cilium Kubernetes Getting Started Guide](https://cilium.readthedocs.io/en/stable/gettingstarted/minikube/)
+[Cilium Kubernetes Getting Started Guide](https://docs.cilium.io/en/stable/gettingstarted/minikube/)
 to perform a basic DaemonSet installation of Cilium in minikube.
 
-To start minikube, minimal version required is >= v0.33.1, run the with the
+To start minikube, minimal version required is >= v1.3.1, run the with the
 following arguments:
 
 ```shell
 minikube version
 ```
 ```
-minikube version: v0.33.1
+minikube version: v1.3.1
 ```
 
 ```shell
 minikube start --network-plugin=cni --memory=4096
 ```
 
-For minikube you can deploy this simple ''all-in-one'' YAML file that includes
-DaemonSet configurations for Cilium, and the necessary configurations to connect
-to the etcd instance deployed in minikube as well as appropriate RBAC settings:
+Mount the BPF filesystem:
 
 ```shell
-kubectl create -f  https://raw.githubusercontent.com/cilium/cilium/v1.5/examples/kubernetes/1.14/cilium-minikube.yaml
+minikube ssh -- sudo mount bpffs -t bpf /sys/fs/bpf
+```
+
+For minikube you can deploy this simple ''all-in-one'' YAML file that includes
+DaemonSet configurations for Cilium as well as appropriate RBAC settings:
+
+```shell
+kubectl create -f https://raw.githubusercontent.com/cilium/cilium/v1.6/install/kubernetes/quick-install.yaml
 ```
 ```
 configmap/cilium-config created
-daemonset.apps/cilium created
-clusterrolebinding.rbac.authorization.k8s.io/cilium created
-clusterrole.rbac.authorization.k8s.io/cilium created
 serviceaccount/cilium created
+serviceaccount/cilium-operator created
+clusterrole.rbac.authorization.k8s.io/cilium created
+clusterrole.rbac.authorization.k8s.io/cilium-operator created
+clusterrolebinding.rbac.authorization.k8s.io/cilium created
+clusterrolebinding.rbac.authorization.k8s.io/cilium-operator created
+daemonset.apps/cilium create
+deployment.apps/cilium-operator created
 ```
 
 The remainder of the Getting Started Guide explains how to enforce both L3/L4
@@ -62,7 +71,7 @@ policies using an example application.
 ## Deploying Cilium for Production Use
 
 For detailed instructions around deploying Cilium for production, see:
-[Cilium Kubernetes Installation Guide](https://cilium.readthedocs.io/en/stable/kubernetes/intro/)
+[Cilium Kubernetes Installation Guide](https://docs.cilium.io/en/stable/kubernetes/intro/)
 This documentation includes detailed requirements, instructions and example
 production DaemonSet files.
 
@@ -86,14 +95,8 @@ cilium-6rxbd    1/1     Running   0          1m
 ...
 ```
 
-There are two main components to be aware of:
-
-- One `cilium` Pod runs on each node in your cluster and enforces network policy
+A `cilium` Pod runs on each node in your cluster and enforces network policy
 on the traffic to/from Pods on that node using Linux BPF.
-- For production deployments, Cilium should leverage a key-value store
-(e.g., etcd). The [Cilium Kubernetes Installation Guide](https://cilium.readthedocs.io/en/stable/kubernetes/intro/)
-will provide the necessary steps on how to install this required key-value
-store as well how to configure it in Cilium.
 
 {{% /capture %}}