vendor files

vendor/k8s.io/kubernetes/pkg/proxy/ipvs/README.md

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+# How to use IPVS
+
+This document shows how to use kube-proxy ipvs mode.
+
+## What is IPVS
+
+**IPVS (IP Virtual Server)** implements transport-layer load balancing, usually called Layer 4 LAN switching, as part of
+Linux kernel.
+
+IPVS runs on a host and acts as a load balancer in front of a cluster of real servers. IPVS can direct requests for TCP
+and UDP-based services to the real servers, and make services of real servers appear as irtual services on a single IP address.
+
+## How to use
+
+#### Load IPVS kernel modules
+
+Currently the IPVS kernel module can't be loaded automatically, so first we should use the following command to load IPVS kernel
+modules manually.
+
+```shell
+modprobe ip_vs
+modprobe ip_vs_rr
+modprobe ip_vs_wrr
+modprobe ip_vs_sh
+modprobe nf_conntrack_ipv4
+```
+
+After that, use `lsmod | grep ip_vs` to make sure kernel modules are loaded.
+
+#### Run kube-proxy in ipvs mode
+
+#### Local UP Cluster
+
+Kube-proxy will run in iptables mode by default in a [local-up cluster](https://github.com/kubernetes/community/blob/master/contributors/devel/running-locally.md). 
+
+Users should export the env `KUBEPROXY_MODE=ipvs` to specify the ipvs mode before deploying the cluster if want to run kube-proxy in ipvs mode.
+
+#### Cluster Created by Kubeadm
+
+Kube-proxy will run in iptables mode by default in a cluster deployed by [kubeadm](https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/). 
+
+Since IPVS mode is still feature-gated, users should add the flag `--feature-gates=SupportIPVSProxyMode=true` in `kubeadm init` command
+
+```
+kubeadm init --feature-gates=SupportIPVSProxyMode=true
+```
+
+to specify the ipvs mode before deploying the cluster if want to run kube-proxy in ipvs mode.
+
+If you are using kubeadm with a configuration file, you can specify the ipvs mode adding `SupportIPVSProxyMode: true` below the `featureGates` field.
+Then the configuration file is similar to:
+
+```json
+kind: MasterConfiguration
+apiVersion: kubeadm.k8s.io/v1alpha1
+...
+featureGates:
+  SupportIPVSProxyMode: true
+...
+```
+
+#### Test
+
+Use `ipvsadm` tool to test whether the kube-proxy start succeed. By default we may get result like:
+
+```shell
+# ipvsadm -ln
+IP Virtual Server version 1.2.1 (size=4096)
+Prot LocalAddress:Port Scheduler Flags
+  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
+TCP  10.0.0.1:443 rr persistent 10800
+  -> 10.229.43.2:6443             Masq    1      0          0         
+TCP  10.0.0.10:53 rr      
+UDP  10.0.0.10:53 rr
+```