Multi-machine Vagrantfile with Shorter, Cleaner Syntax Using JSON and Loops

Thursday, November 13, 2014

In a previous post, I provided an example Vagrantfile to create multiple virtual machines. That Vagrantfile works perfectly fine, but it contains a lot of redundant code. Because a Vagrantfile is written in Ruby, it is possible to create a Vagrantfile with shorter, cleaner syntax using JSON and loops.

The following Vagrantfile uses JSON to define the unique parameters (name, mem, cpu, etc.) for each virtual machine. Then, a for each loop will iterate through the JSON to input the necessary values in the virtual machine definition that now only needs to be defined once instead of three times.

Example Vagrantfile

# -*- mode: ruby -*-

# vi: set ft=ruby :

boxes = [
    {
        :name => "server1",
        :eth1 => "192.168.205.10",
        :mem => "1024",
        :cpu => "1"
    },
    {
        :name => "server2",
        :eth1 => "192.168.205.11",
        :mem => "1024",
        :cpu => "2"
    },
    {
        :name => "server3",
        :eth1 => "192.168.205.12",
        :mem => "2048",
        :cpu => "2"
    }
]

Vagrant.configure(2) do |config|

  config.vm.box = "base"

  config.vm.provider "vmware_fusion" do |v, override|
    override.vm.box = "base"
  end

  # Turn off shared folders
  config.vm.synced_folder ".", "/vagrant", id: "vagrant-root", disabled: true

  boxes.each do |opts|
    config.vm.define opts[:name] do |config|
      config.vm.hostname = opts[:name]

      config.vm.provider "vmware_fusion" do |v|
        v.vmx["memsize"] = opts[:mem]
        v.vmx["numvcpus"] = opts[:cpu]
      end

      config.vm.provider "virtualbox" do |v|
        v.customize ["modifyvm", :id, "--memory", opts[:mem]]
        v.customize ["modifyvm", :id, "--cpus", opts[:cpu]]
      end

      config.vm.network :private_network, ip: opts[:eth1]
    end
  end
end

References

Multi-VM Vagrant the DRY way

Vagrantfile example from uksysadmin



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