Do not attempt to configure apt-cacher-ng bucket if it is not installed on the guest machine

lib/vagrant-cachier/bucket/apt_cacher.rb

@@ -13,21 +13,21 @@ module VagrantPlugins
           guest   = machine.guest
 
           if guest.capability?(:apt_cacher_dir)
-            if machine.config.cache.enable_nfs
+            if guest_path = guest.capability(:apt_cacher_dir)
-              guest_path = guest.capability(:apt_cacher_dir)
+              if machine.config.cache.enable_nfs
+                @env[:cache_dirs] << guest_path
 
-              @env[:cache_dirs] << guest_path
+                machine.communicate.tap do |comm|
-
+                  comm.execute("mkdir -p /tmp/vagrant-cache/#{@name}")
-              machine.communicate.tap do |comm|
+                  unless comm.test("test -L #{guest_path}")
-                comm.execute("mkdir -p /tmp/vagrant-cache/#{@name}")
+                    comm.sudo("rm -rf #{guest_path}")
-                unless comm.test("test -L #{guest_path}")
+                    comm.sudo("mkdir -p `dirname #{guest_path}`")
-                  comm.sudo("rm -rf #{guest_path}")
+                    comm.sudo("ln -s /tmp/vagrant-cache/#{@name} #{guest_path}")
-                  comm.sudo("mkdir -p `dirname #{guest_path}`")
+                  end
-                  comm.sudo("ln -s /tmp/vagrant-cache/#{@name} #{guest_path}")
                 end
+              else
+                @env[:ui].info I18n.t('vagrant_cachier.nfs_required', bucket: 'apt-cacher')
               end
-            else
-              @env[:ui].info I18n.t('vagrant_cachier.nfs_required', bucket: 'apt-cacher')
             end
           else
             @env[:ui].info I18n.t('vagrant_cachier.skipping_bucket', bucket: 'apt-cacher')

lib/vagrant-cachier/cap/debian/apt_cacher_dir.rb

@@ -3,9 +3,18 @@ module VagrantPlugins
     module Cap
       module Debian
         module AptCacherDir
+          CACHER_CONF      = '/etc/apt-cacher-ng/acng.conf'
+          CACHER_CACHE_DIR = "$(cat #{CACHER_CONF} | grep CacheDir | cut -d' ' -f 2)"
+
           def self.apt_cacher_dir(machine)
-            # cat /etc/apt-cacher-ng/acng.conf |grep CacheDir
+            cache_dir = nil
-            '/var/cache/apt-cacher-ng'
+            machine.communicate.tap do |comm|
+              return unless comm.test("test -f #{CACHER_CONF}")
+              comm.execute "echo #{CACHER_CACHE_DIR}" do |buffer, output|
+                cache_dir = output.chomp if buffer == :stdout
+              end
+            end
+            return cache_dir
           end
         end
       end