# Getting Started

## Overview/What’s Ryu the Network Operating System

Ryu is an open-sourced Network Operating System which is licensed under Apache v2.0. It supports openflow protocol.

If you are not familiar with Software Defined Network(SDN) and OpenFlow/openflow controller, please refer to openflow org .

The mailing list is available at ryu-devel ML

## Installing Ryu Network Operating System

Extract source code and just type:

    % python ./setup.py install

Then, run ryu-manager. It listens to ip address 0.0.0.0 and port 6633 by default. Then have your openflow switch (hardware or openvswitch OVS) to connect to ryu-manager.

For OVS case, you can done it by

> % ovs-vsctl set-controller <your bridge> tcp:<ip addr>[:<port: default 6633>]

At the moment, ryu-manager supports only tcp method. If you want to use it with openstack nova and quantum OVS plugin, Please refer to Using Ryu Network Operating System with OpenStack as OpenFlow controller.

## invoking application and Configuration

It can be configured by passing configuration file like:

    ryu-manager [generic/application specific options...]

At the moment applications including the following ones are available (And more to come as Ryu evolves.)

> - ryu.app.simple_isolation.SimpleIsolation
> - ryu.app.rest.RestAPI
> - ryu.app.simple_bridge.SimpleSwitch

The generic available is as follows:

    --app-lists: application module name to run;
      repeat this option to specify a list of values
    --help: show help

The options for REST server:

    --wsapi-host: webapp listen host
      (default: '')
    --wsapi-port: webapp listen port
      (default: '8080')
      (an integer)

The options for openflow controller:

    --ofp-listen-host: openflow listen host
      (default: '')
    --ofp-tcp-listen-port: openflow tcp listen port
      (default: '6633')
      (an integer)

The options for log:

    --default-log-level: default log level
      (an integer)
    --log-dir: log file directory
    --log-file: log file name
    --log-file-mode: default log file permission
      (default: '0644')
    --[no]use-stderr: log to standard error
      (default: 'true')
    --use-syslog: output to syslog
      (default: 'False')
    --[no]verbose: show debug output
      (default: 'false')

The option for oslo.config.cfg:

    --config-file: Path to a config file to use. Multiple config files
      can be specified, with values in later files taking precedence.
      (default: [])
    --config-dir: Path to a config directory to pull *.conf files from.
      This file set is sorted, so as to provide a predictable parse order if
      individual options are over-ridden. The set is parsed after the file(s),
      if any, specified via --config-file, hence over-ridden options in the
      directory take precedence.

## Invoking Example

The example is as follows:

    % PYTHONPATH=. ./bin/ryu-manager --wsapi-port 8081 --verbose --app-lists ryu.app.simple_isolation,ryu.app.rest
    loading app ryu.app.simple_isolation
    loading app ryu.app.rest
    loading app ryu.controller.ofp_handler
    creating context dpset
    creating context wsgi
    creating context network
    instantiating app ryu.app.simple_isolation
    instantiating app ryu.app.rest
    instantiating app ryu.controller.ofp_handler
    BRICK dpset
      CONSUMES EventOFPStateChange
      CONSUMES EventOFPPortStatus
      CONSUMES EventOFPSwitchFeatures
    BRICK ofp_event
      PROVIDES EventOFPStateChange TO ['dpset']
      PROVIDES EventOFPPortStatus TO ['dpset', 'SimpleIsolation']
      PROVIDES EventOFPPacketIn TO ['SimpleIsolation']
      PROVIDES EventOFPSwitchFeatures TO ['dpset', 'SimpleIsolation']
      CONSUMES EventOFPEchoRequest
      CONSUMES EventOFPErrorMsg
      CONSUMES EventOFPSwitchFeatures
      CONSUMES EventOFPHello
    BRICK network
    BRICK RestAPI
    BRICK SimpleIsolation
      CONSUMES EventOFPPacketIn
      CONSUMES EventOFPPortStatus
      CONSUMES EventOFPSwitchFeatures