Config#start_opts -> Config#customize

README.md

@@ -65,9 +65,9 @@ Vagrant.configure("2") do |config|
 
   config.vm.provider :lxc do |lxc|
     # Same as 'customize ["modifyvm", :id, "--memory", "1024"]' for VirtualBox
-    lxc.start_opts << 'lxc.cgroup.memory.limit_in_bytes=400M'
+    lxc.customize 'cgroup.memory.limit_in_bytes', '400M'
     # Limits swap size
-    lxc.start_opts << 'lxc.cgroup.memory.memsw.limit_in_bytes=500M'
+    lxc.customize 'cgroup.memory.memsw.limit_in_bytes', '500M'
   end
 
   # ... your puppet / chef / shell provisioner configs here ...

development/Vagrantfile

@@ -63,7 +63,7 @@ Vagrant.configure("2") do |config|
 
     lxc_config.vm.provider :lxc do |lxc|
       # Required to boot nested containers
-      lxc.start_opts << 'lxc.aa_profile=unconfined'
+      lxc.customize 'aa_profile', 'unconfined'
     end
   end
 

example/Vagrantfile

@@ -27,8 +27,8 @@ Vagrant.configure("2") do |config|
   config.vm.synced_folder cache_dir, "/var/cache/apt/archives"
 
   config.vm.provider :lxc do |lxc|
-    lxc.start_opts << 'lxc.cgroup.memory.limit_in_bytes=400M'
-    lxc.start_opts << 'lxc.cgroup.memory.memsw.limit_in_bytes=500M'
+    lxc.customize 'cgroup.memory.limit_in_bytes', '400M'
+    lxc.customize 'cgroup.memory.memsw.limit_in_bytes', '500M'
   end
 
   config.vm.provision :shell, :inline => <<-SCRIPT

lib/vagrant-lxc/action/share_folders.rb

@@ -9,7 +9,7 @@ module Vagrant
         def call(env)
           @env = env
           prepare_folders
-          add_start_opts
+          add_override_configs
           @app.call env
         end
 
@@ -47,7 +47,7 @@ module Vagrant
           end
         end
 
-        def add_start_opts
+        def add_override_configs
           @env[:ui].info I18n.t("vagrant.actions.lxc.share_folders.preparing")
 
           folders = []

lib/vagrant-lxc/config.rb

@@ -1,14 +1,31 @@
 module Vagrant
   module LXC
     class Config < Vagrant.plugin("2", :config)
-      # An array of options to be passed to lxc-start when booting the machine.
+      # An array of container's configuration overrides to be provided to `lxc-start`.
       #
       # @return [Array]
-      attr_reader :start_opts
+      attr_reader :customizations
 
       def initialize
-        @start_opts         = []
+        @customizations = []
       end
+
+      # Customize the container by calling `lxc-start` with the given
+      # configuration overrides.
+      #
+      # For example, if you want to set the memory limit, you can use it
+      # like: config.customize 'cgroup.memory.limit_in_bytes', '400M'
+      #
+      # When `lxc-start`ing the container, vagrant-lxc will pass in
+      # "-s lxc.cgroup.memory.limit_in_bytes=400M" to it.
+      #
+      # @param [String] key Configuration key to override
+      # @param [String] value Configuration value to override
+      def customize(key, value)
+        @customizations << [key, value]
+      end
+
+      # TODO: At some point in the future it would be nice to validate these options
     end
   end
 end

lib/vagrant-lxc/driver.rb

@@ -55,19 +55,19 @@ module Vagrant
             end
           end
 
-          config.start_opts << "lxc.mount.entry=#{folder[:hostpath]} #{guestpath} none bind 0 0"
+          # TODO: Move outside
+          config.customize 'mount.entry', "#{folder[:hostpath]} #{guestpath} none bind 0 0"
         end
       end
 
       def start(config)
         @logger.info('Starting container...')
 
-        opts = config.start_opts.dup
         if ENV['LXC_START_LOG_FILE']
           extra = ['-o', ENV['LXC_START_LOG_FILE'], '-l', 'DEBUG']
         end
 
-        @cli.transition_to(:running) { |c| c.start(opts, (extra || nil)) }
+        @cli.transition_to(:running) { |c| c.start(config.customizations, (extra || nil)) }
       end
 
       def halt

lib/vagrant-lxc/driver/cli.rb

@@ -45,10 +45,10 @@ module Vagrant
           run :destroy, '--name', @name
         end
 
-        def start(configs = [], extra_opts = [])
-          configs = configs.map { |conf| ["-s", conf] }.flatten
-          configs += extra_opts if extra_opts
-          run :start, '-d', '--name', @name, *configs
+        def start(overrides = [], extra_opts = [])
+          options = overrides.map { |key, value| ["-s", "lxc.#{key}=#{value}"] }.flatten
+          options += extra_opts if extra_opts
+          run :start, '-d', '--name', @name, *options
         end
 
         def shutdown

spec/spec_helper.rb

@@ -17,6 +17,7 @@ Dir[File.dirname(__FILE__) + "/support/**/*.rb"].each { |f| require f }
 if ENV['VERIFY_CONSTANT_NAMES']
   require 'vagrant-lxc/plugin'
   require 'vagrant-lxc/provider'
+  require 'vagrant-lxc/config'
 end
 
 require 'rspec/fire'

spec/unit/driver/cli_spec.rb

@@ -80,8 +80,8 @@ describe Vagrant::LXC::Driver::CLI do
       )
     end
 
-    it 'uses provided hash to configure the container' do
-      subject.start(['lxc.config=value', 'lxc.other=value'])
+    it 'uses provided array to override container configs' do
+      subject.start([['config', 'value'], ['other', 'value']])
       subject.should have_received(:run).with(:start, '-d', '--name', name,
         '-s', 'lxc.config=value',
         '-s', 'lxc.other=value'

spec/unit/driver_spec.rb

@@ -70,8 +70,8 @@ describe Vagrant::LXC::Driver do
   end
 
   describe 'start' do
-    let(:config) { mock(:config, start_opts: ['a=1', 'b=2']) }
     let(:name)   { 'container-name' }
+    let(:config) { fire_double('Vagrant::LXC::Config', customizations: [['a', '1'], ['b', '2']]) }
     let(:cli)    { fire_double('Vagrant::LXC::Driver::CLI', start: true) }
 
     subject { described_class.new(name, cli) }
@@ -81,7 +81,7 @@ describe Vagrant::LXC::Driver do
     end
 
     it 'starts container with configured lxc settings' do
-      cli.should_receive(:start).with(['a=1', 'b=2'], nil)
+      cli.should_receive(:start).with(config.customizations, nil)
       subject.start(config)
     end