containernetworking-plugins/plugins/meta/tuning

tuning plugin

Overview

This plugin can change some system controls (sysctls) and several netlink attributes (promiscuous mode and mac) in the network namespace. It does not create any network interfaces and therefore does not bring connectivity by itself. It is only useful when used in addition to other plugins.

System Controls Operation

The following network configuration file

{
  "name": "mytuning",
  "type": "tuning",
  "sysctl": {
          "net.core.somaxconn": "500"
  }
}

will set /proc/sys/net/core/somaxconn to 500. Other sysctls can be modified as long as they belong to the network namespace (/proc/sys/net/*).

A successful result would simply be:

{ }

Network sysctls documentation

Some network sysctls are documented in the Linux sources:

• Documentation/sysctl/net.txt
• Documentation/networking/ip-sysctl.txt
• Documentation/networking/

Netlink Operation

The parameters, "mac", "mtu" and "promisc", changes the interface attributes as followings:

{
  "name": "mytuning",
  "type": "tuning",
  "promisc": true,
  "mac": "c2:b0:57:49:47:f1",
  "mtu": 1454
}

Netlink configuration reference

• mac (string, optional): MAC address (i.e. hardware address) of interface
• mtu (integer, optional): MTU of interface
• promisc (bool, optional): Change the promiscas mode of interface

Supported arguments

The following CNI_ARGS are supported:

• MAC: request a specific MAC address for the interface

  (example: CNI_ARGS="IgnoreUnknown=true;MAC=c2:11:22:33:44:55")

Note: You may add IgnoreUnknown=true to allow loose CNI argument verification (see CNI's issue#560).