mruby-ipvs

mruby-ipvs is an interface to the IP Virtual Server(IPVS) for mruby.

Installation

• Install dependencies.

apt-get -y install libnl-dev # or yum -y install libnl-devel, and so on...

• Clone mruby

git clone https://github.com/mruby/mruby/ /usr/local/src/mruby

• Set up build_config.rb

Use mgem (recommended)

mgem add mruby-ipvs

# and add some mgems if you want
# mgem add ...

mgem config default > /usr/local/src/mruby/build_config.rb # generate build_config.rb

or add conf.gem line to build_config.rb (/usr/local/src/mruby/build_config.rb).

MRuby::Build.new do |conf|
  # ... (snip) ...
  conf.gem :git => 'https://github.com/rrreeeyyy/mruby-ipvs', :options => '--recursive'
end

• Build mruby

cd /usr/local/src/mruby && ruby ./minirake

• Check the instllation

/usr/local/src/mruby/build/host/bin/mruby -e 'p IPVS'
IPVS

Examples

• Add service.

# Create IPVS::Service instance.
s = IPVS::Service.new({
  'addr' => '10.0.0.1',
  'port' => 80,
  'sched_name' => 'wrr'
})

# apply to IPVS.
s.add_service

• Add destination.

# Create IPVS::Dest instance.
d1 = IPVS::Dest.new({
  'addr' => '192.168.0.1',
  'port' => 80,
  'weight' => 1
})

d2 = IPVS::Dest.new({
  'addr' => '192.168.0.2',
  'port' => 80,
  'weight' => 1,
  'conn' => 'DR'
})

# Add destination to IPVS::Service instance.
s.add_dest(d1)
s.add_dest(d2)

# Change the destination weight, connection flag.
d1.weight = 3
d2.conn = 'TUN'

• Sync daemon start/stop

# Create IPVS::Daemon instance.
daemon = IPVS::Daemon.new({
  'state' => 'master',            # "master" or "backup"
  'ifname' => 'eth0',
  'syncid' => 1
})
daemon.start()                    # you can daemon.stop() after start.

• Check the results

$ cat /proc/net/ip_vs
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP  0A000001:0050 wrr
  -> C0A80002:0050      Tunnel  1      0          0
  -> C0A80001:0050      Masq    3      0          0

• Check the sync daemon multicast group

# netstat -anu | grep 224.0.0.81:8848
udp        0      0 10.0.2.15:50758         224.0.0.81:8848         ESTABLISHED

• more examples in examples/.
  • examples/keepalived.rb: DSL like keepalived.

Docker

You can run mruby-ipvs with docker.

• Build docker image:

docker build -t mruby-ipvs .

• In docker host machine, load ip_vs kernel module.

modprobe ip_vs

or if you use docker-machine, just type:

docker-machine ssh ${DOCKER_MACHINE_NAME:-default} sudo modprobe ip_vs

• Then just docker run:

docker run -d mruby-ipvs ${MRUBY_FILE}

Development

Local Source Testing (Requirements: Vagrant)

$ git clone https://github.com/rrreeeyyy/mruby-ipvs/
$ cd mruby-ipvs
$ git submodule update --init
$ vagrant up
$ vagrant ssh -c 'cd /usr/local/src/mruby && rake test'

More Information

• [in Japanese] http://rrreeeyyy.com/blog/2014/03/17/mruby-ipvs/ (blog)
• [in Japanese] https://speakerdeck.com/rrreeeyyy/mruby-ipvs (presentation)
• [in Japanese] http://rrreeeyyy.com/thesis/thesis.pdf (graduation thesis)

Contributing

1. Fork it ( https://github.com/rrreeeyyy/mruby-ipvs/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

License

GNU General Public License Version 2