folder sharing: check

Closes #9

README.md

@@ -55,6 +55,13 @@ gets installed, create a `Vagrantfile` like the one below and run `vagrant-lxc u
 ```ruby
 Vagrant.configure("2") do |config|
   config.vm.box = "ubuntu-cloud"
+
+  # Share an additional folder to the guest Container. The first argument
+  # is the path on the host to the actual folder. The second argument is
+  # the path on the guest to mount the folder. And the optional third
+  # argument is a set of non-required options.
+  config.vm.synced_folder "/tmp", "/host_tmp"
+
   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'

example/Vagrantfile

@@ -7,6 +7,8 @@ Vagrant.configure("2") do |config|
   config.vm.box      = "ubuntu-cloud"
   config.vm.hostname = 'ubuntu-cloud-box'
 
+  config.vm.synced_folder "/tmp", "/vagrant_data"
+
   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'

lib/vagrant-lxc/action.rb

@@ -9,6 +9,7 @@ require 'vagrant-lxc/action/created'
 require 'vagrant-lxc/action/destroy'
 require 'vagrant-lxc/action/handle_box_metadata'
 require 'vagrant-lxc/action/is_running'
+require 'vagrant-lxc/action/share_folders'
 
 module Vagrant
   module LXC
@@ -46,7 +47,7 @@ module Vagrant
           b.use Vagrant::Action::Builtin::Provision
           b.use Vagrant::Action::Builtin::EnvSet, :port_collision_repair => true
           b.use PrepareForwardedPortCollisionParams
-          b.use ClearSharedFolders
+          # b.use ClearSharedFolders
           b.use ShareFolders
           b.use Network
           b.use ForwardPorts
@@ -86,7 +87,7 @@ module Vagrant
           end
           b.use action_start
           b.use AfterCreate
-          b.use Vagrant::Action::Builtin::SetHostname
+          # b.use Vagrant::Action::Builtin::SetHostname
         end
       end
 
@@ -164,9 +165,6 @@ module Vagrant
       # TODO: Check if our requirements are met.
       class CheckLXC < BaseAction; end
 
-      # TODO: Implement folder sharing with "mount"
-      class ShareFolders < BaseAction; end
-
       # TODO: Sets up all networking for the container instance. This includes
       # host only networks, bridged networking, forwarded ports, etc.
       class Network < BaseAction; end

lib/vagrant-lxc/action/share_folders.rb

@@ -0,0 +1,63 @@
+module Vagrant
+  module LXC
+    module Action
+      class ShareFolders < BaseAction
+        def call(env)
+          @env = env
+          prepare_folders
+          add_start_opts
+          @app.call env
+        end
+
+        # This method returns an actual list of VirtualBox shared
+        # folders to create and their proper path.
+        def shared_folders
+          {}.tap do |result|
+            @env[:machine].config.vm.synced_folders.each do |id, data|
+              # Ignore NFS shared folders
+              next if data[:nfs]
+
+              # This to prevent overwriting the actual shared folders data
+              result[id] = data.dup
+            end
+          end
+        end
+
+        # Prepares the shared folders by verifying they exist and creating them
+        # if they don't.
+        def prepare_folders
+          shared_folders.each do |id, options|
+            hostpath = Pathname.new(options[:hostpath]).expand_path(@env[:root_path])
+
+            if !hostpath.directory? && options[:create]
+              # Host path doesn't exist, so let's create it.
+              @logger.debug("Host path doesn't exist, creating: #{hostpath}")
+
+              begin
+                hostpath.mkpath
+              rescue Errno::EACCES
+                raise Vagrant::Errors::SharedFolderCreateFailed,
+                  :path => hostpath.to_s
+              end
+            end
+          end
+        end
+
+        def add_start_opts
+          @env[:ui].info I18n.t("vagrant.actions.vm.share_folders.creating")
+
+          folders = []
+          shared_folders.each do |id, data|
+            folders << {
+              :name      => id,
+              :hostpath  => File.expand_path(data[:hostpath], @env[:root_path]),
+              :guestpath => data[:guestpath]
+            }
+          end
+          config = @env[:machine].provider_config
+          @env[:machine].provider.container.share_folders(folders, config)
+        end
+      end
+    end
+  end
+end

lib/vagrant-lxc/container.rb

@@ -66,6 +66,26 @@ module Vagrant
         end
       end
 
+      def rootfs_path
+        Pathname.new("#{CONTAINERS_PATH}/#{@name}/rootfs")
+      end
+
+      def share_folders(folders, config)
+        folders.each do |folder|
+          guestpath = rootfs_path.join(folder[:guestpath].gsub(/^\//, ''))
+          unless guestpath.directory?
+            begin
+              system "sudo mkdir -p #{guestpath.to_s}"
+            rescue Errno::EACCES
+              raise Vagrant::Errors::SharedFolderCreateFailed,
+                :path => guestpath.to_s
+            end
+          end
+
+          config.start_opts << "lxc.mount.entry=#{folder[:hostpath]} #{guestpath} none bind 0 0"
+        end
+      end
+
       def start(config)
         # @logger.info('Starting container...')
         opts = config.start_opts.map { |opt| ["-s", opt] }.flatten