Introduction

l2mesh is a tinc based virtual switch, implemented as a puppet module.

It creates a new ethernet interface on the machine and connects it to the switch.

Here is how the situation looks like when dealing with physical machines and a hardware switch:

+----------------+                        +---------------+
|                |                        |               |
|          +-----+                        +-----+         |
| MACHINE  | eth0+---------+    +---------+eth0 | MACHINE |
|    A     +-----+         |    |         +-----+   C     |
|                |         |    |         |               |
+----------------+     +---+----+---+     +---------------+
                       |  SWITCH    |
                       +-----+------+
                             |
+----------------+           |
|                |           |
|          +-----+           |
| MACHINE  | eth0+-----------+
|    B     +-----+
|                |
+----------------+

Each of the three machines ( A, B, C ) have a physical ethernet connector which shows as eth0. They are connected with a cable to a SWITCH which transmits the packet coming from MACHINE A to MACHINE B or MACHINE C.

With l2mesh, a new virtual interface ( named tun0 below ) is created on each machine and they are all connected by a TINC daemon. Packets go from MACHINE A to MACHINE B or MACHINE C as if they were connected to a physical switch.

+---------+-----+
|         |eth0 |
|         +-----+
| MACHINE |tun0 |
|    A    +-----+
|           TINC+---
+--------------++   \-------
               |            \-------   +---------------+
               |                    X--+TINC           |
               |            /-------   +-----+         |
 +-------------+-+   /------           |tun0 | MACHINE |
 |           TINC+---                  +-----+    C    |
 |         +-----+                     |eth0 |         |
 | MACHINE |tun0 |                     +-----+---------+
 |    B    +-----+
 |         |eth0 |
 +---------+-----+

Here is how it looks on each machine:

$ ip link show eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
   link/ether fa:16:3e:48:ae:6f brd ff:ff:ff:ff:ff:ff

$ ip link show dev tun0
2: tun0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
   link/ether 72:75:6e:60:59:f0 brd ff:ff:ff:ff:ff:ff

Usage

l2mesh is a puppet module that should be installed in the puppet master as follows

git clone http://redmine.the.re/git/l2mesh.git /etc/puppet/modules/l2mesh

Here is an example usage that can be included in /etc/puppet/manifests/site.pp

node /MACHINE-A.example.com/, /MACHINE-B.example.com/ {

  class { 'l2mesh':
    interface     => 'eth0'
    ip            => $::ipaddress_eth0,
    port          => 656,
    tunnel_device => 'tun0',
    tunnel_ip     => '192.168.255.1',
  }
}

On both MACHINE-A and MACHINE-B, it will

create the tun0 ethernet interface
run the tincd daemon to listen on port 656 and bind it to the $::ipaddress_eth0 IP address

In addition, both machines will try to reach each other:

tincd on MACHINE-A will try to connect to tincd on MACHINE-B
tincd on MACHINE-B will try to connect to tincd on MACHINE-A

Adding a new machine to the tun virtual switch is done by adding the hostname of the machine to the node list. For instance, MACHINE-C.example.com can be added with:

node /MACHINE-A.example.com/, /MACHINE-B.example.com/, /MACHINE-C.example.com/  {
...

l2mesh is not

l2mesh is not an equivalent to brctl : it is a switch made of tinc daemons running on multiple machines

Implementation

See the implementation notes at the beginning of the file manifests/init.pp

License

Copyright (C) 2012 eNovance <licensing@enovance.com>
              2014 Joe Topjian <joe@topjian.net>

Authors:
Loic Dachary <loic@dachary.org>
Joe Topjian <joe@topjian.net>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

Running tests

l2mesh has been heavily rewritten. Tests do not work right now.

apt-get install -y tinc
apt-get install -y ruby1.8 rubygems
apt-get remove -y ruby1.9.1
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 1.1.3 diff-lcs
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 1.6.14 facter
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 0.0.1 metaclass
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 0.13.0 mocha
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 2.7.18 puppet
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 0.1.13 puppet-lint
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 0.2.0 puppetlabs_spec_helper
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 10.0.2 rake
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 2.12.0 rspec
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 2.12.0 rspec-core
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 2.12.0 rspec-expectations
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 2.12.0 rspec-mocks
GEM_HOME=$HOME/.gem-installed gem install --include-dependencies --no-rdoc --no-ri --version 0.1.4 rspec-puppet
export PATH=$HOME/.gem-installed/bin:$PATH ; GEM_HOME=$HOME/.gem-installed rake spec

jtopjian / l2mesh