Added IPV6 information to setup cluster using kubeadm

docs/reference/generated/kubeadm.md

@@ -67,7 +67,7 @@ following steps:
    See [Securing your installation](#securing-more) for hardening.
 
 1. kubeadm installs add-on components via the API server.  Right now this is
-   the internal DNS server and the kube-proxy DaemonSet.
+   the internal DNS server and the kube-proxy DaemonSet. There is no requirement for specifying kube-proxy bind address in kubeadm configuration file. The kube-proxy bind address is dynamically assigned based on the address type of API server (i.e. v4 will assign 0.0.0.0 & v6 will assign :: ).
 
 1. If `kubeadm init` is invoked with the alpha self-hosting feature enabled,
    (`--feature-gates=SelfHosting=true`), the static Pod based control plane will
@@ -110,10 +110,7 @@ flags that can be used to customise the Kubernetes installation.
 
 - `--apiserver-advertise-address`
 
-  This is the address the API Server will advertise to other members of the
-  cluster.  This is also the address used to construct the suggested `kubeadm
-  join` line at the end of the init process.  If not set (or set to 0.0.0.0) then
-  IP for the default interface will be used.
+  This is the address, the API Server will advertise to other members of the cluster. The API server IP address can either be IPv4 or IPv6. This is also the address used to construct the suggested kubeadm join line at the end of the init process. If not set (or set to 0.0.0.0 for IPv4 or :: for IPv6) then the IP for the default interface will be used.
 
   This address is also added to the certificate that the API Server uses.
 
@@ -1030,6 +1027,25 @@ More information on custom arguments can be found here:
 - [kube-controller-manager](https://kubernetes.io/docs/admin/kube-controller-manager/)
 - [kube-scheduler](https://kubernetes.io/docs/admin/kube-scheduler/)
 
+### Specifying custom arguments for IPv6 interfaces
+
+Optionally, IPv6 (for a liveness probe for control plane components) and etcd server can also be specified using extra args as mentioned in the following example. Please note that whenever IPv6 needs to be specified as IP:Port, the IPv6 hostname must be enclosed.
+
+```
+apiVersion: kubeadm.k8s.io/v1alpha1
+kind: MasterConfiguration
+apiServerExtraArgs:
+  etcd-servers: "http://[fd00::101]:2379"
+controllerManagerExtraArgs:
+  address: "fd00::101"
+schedulerExtraArgs:
+  address: "fd00::101"
+etcd:
+  extraArgs:
+    listen-client-urls: "http://[fd00::101]:2379"
+```
+
+
 ## Releases and release notes
 
 If you already have kubeadm installed and want to upgrade, run `apt-get update

docs/setup/independent/create-cluster-kubeadm.md

@@ -115,9 +115,8 @@ something provider-specific. The tabs below will contain a notice about what fla
 on `kubeadm init` are required.
 - Unless otherwise specified, kubeadm uses the default gateway's network interface 
 to advertise the master's IP. If you want to use a different network interface, specify 
-`--apiserver-advertise-address=<ip-address>` argument to `kubeadm init`.
-- If you would like to customise control plane components, you can do so by providing 
-extra args to each one, as documented [here](/docs/admin/kubeadm#custom-args).
+`--apiserver-advertise-address=<ip-address>` argument to `kubeadm init`. To deploy an IPv6 Kubernetes cluster using IPv6 addressing, you must specify an IPv6, e.g. `--apiserver-advertise-address=fd00::101` 
+- If you would like to customise control plane components including optional IPv6 assignment to liveness probe for control plane components and etcd server, you can do so by providing extra args to each one, as documented [here](/docs/admin/kubeadm#custom-args).
 - `kubeadm init` will first run a series of prechecks to ensure that the machine
 is ready to run Kubernetes.  It will expose warnings and exit on errors. It
 will then download and install the cluster database and control plane
@@ -211,7 +210,7 @@ supports Container Network Interface (CNI) based networks (and does not support
 
 Several projects provide Kubernetes pod networks using CNI, some of which also
 support [Network Policy](/docs/concepts/services-networking/networkpolicies/). See the [add-ons
-page](/docs/concepts/cluster-administration/addons/) for a complete list of available network add-ons.
+page](/docs/concepts/cluster-administration/addons/) for a complete list of available network add-ons. IPv6 support was added in [CNI v0.6.0](https://github.com/containernetworking/cni/releases/tag/v0.6.0). [CNI bridge](https://github.com/containernetworking/plugins/blob/master/plugins/main/bridge/README.md) and [local-ipam](https://github.com/containernetworking/plugins/blob/master/plugins/ipam/host-local/README.md) are the only supported IPv6 network plugins in 1.9.
 
 **New for Kubernetes 1.6:** kubeadm 1.6 sets up a more secure cluster by
 default.  As such it uses RBAC to grant limited privileges to workloads running
@@ -371,6 +370,9 @@ The nodes are where your workloads (containers and pods, etc) run. To add new no
   kubeadm join --token <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>
   ```
 
+**Note:** To specify an IPv6 tuple for <master-ip>:<master-port>, IPv6 address must be enclosed in square brackets, for example: `[fd00::101]:2073`.
+{: .note}
+
 The output should look something like:
 
 ```