github
/
k3s
mirror of https://github.com/k3s-io/k3s
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Merge pull request #56325 from m1093782566/ipvs-readme 

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Update IPVS README

**What this PR does / why we need it**:

People complained that they feel confused about how to use IPVS-based kube-proxy correctly, probably we may need to provide them a better README.

**Which issue(s) this PR fixes**: 

xref: #56319

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```
pull/6/head
Kubernetes Submit Queue 2017-12-13 19:32:11 -08:00 committed by GitHub
parent bdd4820fed f55c1ea78e
commit 9a03e7e17d
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 35 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
pkg/proxy/ipvs/README.md
View File

@ -10,32 +10,17 @@ 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 virtual services on a single IP address.
## How to use
## Run kube-proxy in ipvs mode
#### Load IPVS kernel modules
Currently, local-up scripts and kubeadm support switching IPVS proxy mode via exporting environment variables or specifying flags.
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
### 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
### 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/).
@ -56,12 +41,14 @@ apiVersion: kubeadm.k8s.io/v1alpha1
...
featureGates:
SupportIPVSProxyMode: true
...
mode: ipvs
```
#### Test
## Debug
Use `ipvsadm` tool to test whether the kube-proxy start succeed. By default we may get result like:
### Check IPVS proxy rules
People can use `ipvsadm` tool to check whether kube-proxy are maintaining IPVS rules correctly. For example, we may get IPVS proxy rules like:
```shell
# ipvsadm -ln
@ -73,3 +60,29 @@ TCP 10.0.0.1:443 rr persistent 10800
TCP 10.0.0.10:53 rr
UDP 10.0.0.10:53 rr
```
### Why kube-proxy can't start IPVS mode
People can do the following check list step by step:
**1. Enable IPVS feature gateway**
Currently IPVS-based kube-proxy is still in alpha phase, people need to enable `--feature-gates=SupportIPVSProxyMode=true` explicitly.
**2. Specify proxy-mode=ipvs**
Tell kube-proxy that proxy-mode=ipvs, please.
**3. Load ipvs required kernel modules**
The following kernel modules are required by IPVS-based kube-proxy:
```shell
ip_vs
ip_vs_rr
ip_vs_wrr
ip_vs_sh
nf_conntrack_ipv4
```
IPVS-based kube-proxy will load them automatically. If it fails to load them, please check whether they are compiled into your kernel.