config.rb

require 'open-uri'
require 'yaml'

# Size of the CoreOS cluster created by Vagrant
$num_instances=3

# coreos-vagrant is configured through a series of configuration
# options (global ruby variables) which are detailed below. To modify
# these options simply uncomment the necessary lines, leaving the $, 
# and replace everything after the equals sign..

# Used to fetch a new discovery token for a cluster of size $num_instances
$new_discovery_url="https://discovery.etcd.io/new?size=#{$num_instances}"

# To automatically replace the discovery token on 'vagrant up', uncomment
# the lines below:

# TODO automatically replace token in ```*.user-data``` file
token = open($new_discovery_url).read
Dir.glob('*.user-data').each do |f|
if File.exists?(f) && ARGV[0].eql?('up')

 data = YAML.load(IO.readlines(f)[1..-1].join)
 if data['coreos'].key? 'etcd'
   data['coreos']['etcd']['discovery'] = token
 end
 if data['coreos'].key? 'etcd2'
   data['coreos']['etcd2']['discovery'] = token
 end

 yaml = YAML.dump(data)
 File.open(f, 'w') { |file| file.write("#cloud-config\n\n#{yaml}") }
end
end

# Change the version of CoreOS to be installed
# To deploy a specific version, simply set $image_version accordingly. 
# For example, to deploy version 709.0.0, set $image_version="709.0.0".
# The default value is "current", which points to the current version
# of the selected channel
$image_version = "current"

# Official CoreOS channel from which updates should be downloaded
$update_channel='beta'

# Log the serial consoles of CoreOS VMs to log/
# Enable by setting value to true, disable with false
# WARNING: Serial logging is known to result in extremely high CPU usage with
# VirtualBox, so should only be used in debugging situations
$enable_serial_logging=false

# Enable port forwarding of Docker TCP socket
# Set to the TCP port you want exposed on the *host* machine, default is 2375
# If 2375 is used, Vagrant will auto-increment (e.g. in the case of $num_instances > 1)
# You can then use the docker tool locally by setting the following env var:
#   export DOCKER_HOST='tcp://127.0.0.1:2375'
$expose_docker_tcp=2375

# Setting for VirtualBox VMs
$vb_gui = false
$vb_memory = 2048
$vb_cpus = 2

# Share additional folders to the CoreOS VMs
# For example,
# $shared_folders = {'/path/on/host' => '/path/on/guest', '/home/foo/app' => '/app'}
# or, to map host folders to guest folders of the same name,
# $shared_folders = Hash[*['/home/foo/app1', '/home/foo/app2'].map{|d| [d, d]}.flatten]
$shared_folders = {'jenkins-data' => '/jenkins-data'}

# Enable port forwarding from guest(s) to host machine, syntax is: { 80 => 8080 }, auto correction is enabled by default.
$forwarded_ports = {}