RYU 学习指南State Key Laboratory of Networking and Switching Technology

Future Networking LaboratoryCheng Li

AgendaWhat is RYU

How RYU workHow to develop

What RYU can do

What is RYU

Ryu is a component-based software defined networking framework.

What is RYU

OSS SDN Framework founded by NTT:•Python library for SDN•Apache v2 license•Supports various protocols for managing network devices: - OpenFlow, Netconf, OF-config, SNMP etc.

Features:•OpenFlow - Version:1.0,1.2,1.3,1.4,1.5•Parsing and building various protocols packets: - IP, UDP,TCP,MPLS…•Ryu can configure Open vSwitch directly without ovs-vsctl, ovsdb-client•Integration with other project - OpenStack - HA with Zookeeper - IDS(Intrusion Detection System) with snort

What RYU can do

• Various SDN Application and library: - simple_switch firewall router… - LACP,STP… - RESTAPI, RPC• Integration with other project: - OpenStack - HA with Zookeeper - IDS(Intrusion Detection System) with snort

• Topology Viewer - Topology discovery - Flow entry management.

Mininet 创建的 host ， switch 等实例实际上是运行在不同 namespace 下的某个进程。默认情况下 Host 运行在自己的 namespace 中，交换节点运行在 root namespace 中。

User RYU 在工业界得到了不错的应用，使用 RYU 作为控制器的厂家包括 pica8, centec ， broadcom 等。开源软件交换机 OVS,CPQD 等也均支持 RYU 控制器。更多企业的 SDN 解决方案采用 RYU控制器。

RYU 以其轻巧，快速开发，协议支持完整，支持和其他开源软件协同工作的特点，在开源控制器的竞争中获得了一席之地。

Ref: http://www.slideshare.net/apnic/ryu-sdn-framework?qid=b548fb40-1f9d-477c-ad35-2b9c85f47358&v=default&b=&from_search=1

How to develop• Installation

• Getting started

• CLI

• GUI

• RESTAPI

• Simple_switch

Installation• Pip install

~pip install ryu

• Native Installation form Source~git clone https://github.com/osrg/ryu.git~cd ryu~sudo python setup.py install

• Installhelper~git clone https://github.com/sdnds-tw/ryuInstallHelper.git~cd ryuInstallHelper~./ryuInstallHelper.sh

Getting StartedStartup Options

●ryu-manager 启动 ryu, 如果不加任何参数，则默认启动 ofphandler 模块。●ryu run 等同于 ryu-manager●Ryu-manager –h 查看帮助信息●--verbose 打印详细信息●--version●--observe-links 自动下发 LLDP ，用于拓扑发现。●…

●Example: ryu-manager simple_switch.py ofctl_rest.py –observe-links

CLICLI register

●参数注册统一使用 oslo ： OpenStack Common Libraries 。

●cfg.py: CONF=oslo.config.cfg.ConfigOpts()

●from ryu import cfg :cfg 模块定义了 CONF 对象

●CONF.register_cli_opts([cfg.StrOpt(“wsapi-port”, default =8080, help = ‘webapp listen port’ )])

GUI● 使用官方 GUI

o 官方提供 GUI 套件o 详细教程：

http://www.muzixing.com/pages/2015/04/21/ryu316-guian-zhuang-yu-topologymo-kuai-fen-xi.html

● 使用第三方 GUIo 第三方 GUI 提供者有很多o http://sdnhub.org/releases/sdn-starter-kit-ryu/o ANT GUI

GUI

GUI

GUI

RESAT APIRYU 提供了 RESTAPI ， 用于可以使用 RESTAPI 来开发应用程序。•Ofctl_rest.py 提供 OpenFlow 方面的 REST API 接口：

get the list of all switches GET /stats/switches get the desc stats of the switch GET /stats/desc/<dpid> get flows stats of the switch GET /stats/flow/<dpid> get flows stats of the switch filtered by the fields ： POST /stats/flow/<dpid>

•Rest_topology.py 提供获取拓扑相关 API: get all the switches GET /v1.0/topology/switches get the switch GET /v1.0/topology/switches/<dpid> get all the links GET /v1.0/topology/links get the links of a switch GET /v1.0/topology/links/<dpid>

Write your first APPhttp://ryu.readthedocs.org/en/latest/writing_ryu_app.html

Program model

Simple hub

Simple hub

Controller

SwitchHost A Host C

Host B

Packet Packet

Packet

Packet INPacket out

Simple hub

控制器需要做的事情：•创建一个 app 类，用于描述 hub 的行为：

•注册监听 Packet_in 事件的处理函数，用于处理 packet_in 事件

Event

EventOFPMsgBase

Eventbase

OFPEVENT

EventMSG(datapath, version,msg_type, msg_len, xid, buf)

Datapath

ProtocolDesc(ofproto, ofproto_parser)

Others

OFPActionOutput

OFPActionOutput

OFPAction

OFPActionHeader

StringifyMixin

Simple switch

控制器需要做的事情：•创建一个 app 类，用于描述 switch 的行为：

•注册监听 Packet_in 事件的处理函数，用于处理 packet_in 事件：相比 hub ，多了 MAC 地址自学习功能

•链接： http://osrg.github.io/ryu-book/en/html/switching_hub.html

Parsing Packet

Building Packet

Traffic Monitor

控制器需要做的事情：•创建一个 app 类，用于描述流量监控，继承 Simple switch ；

•完成发送获取网络信息报文的函数；

•注册处理统计数据回复报文的 handler 。

•教程：•http://osrg.github.io/ryu-book/en/html/traffic_monitor.html•http://www.muzixing.com/pages/2015/03/04/traffic-monitor-in-ryu.html

Controller

Switch

Stats_reqeust Stats_reply

How RYU work• Architecture

• RYU code

• Call Graph

Architecture

RYU code

Call Graph

Data plane

Main(RYU)

AppManager

Service brick (event router)

OpenVSwitch

OFHandler(RyuAPP)

ofprotoofproto_v1_* ofproto_v1_*_parser

OpenFlowController

Hello handler

Switch features handler

Handlers…

libARP ipv4… icmp

Datapaths

dp1 dp2 dp3 dpn

StreamServer

OpenVSwitch

OpenVSwitchSocket Client

Read&wirte socketSocket server

connect

CONF

APPn APP2 OFPHandlerAPP list

even

t event

event

response

New datapath

Thank youMUZIXING.COM

State Key Laboratory of Networking and Switching TechnologyFuture Networking Laboratory

Cheng Li