Merge pull request #383 from stucki/use-system-bridge

Use system bridge

lib/vagrant-lxc/action/gc_private_network_bridges.rb

@@ -35,8 +35,9 @@ module Vagrant
 
             if ! driver.bridge_is_in_use?(bridge)
               env[:ui].info I18n.t("vagrant_lxc.messages.remove_bridge", name: bridge)
-              # TODO: Output that bridge is being removed
-              driver.remove_bridge(bridge)
+              unless ['lxcbr0', 'virbr0'].include? bridge
+                driver.remove_bridge(bridge)
+              end
             end
           end
         end

lib/vagrant-lxc/driver.rb

@@ -170,6 +170,11 @@ module Vagrant
       end
 
       def remove_bridge(bridge_name)
+        if ['lxcbr0', 'virbr0'].include? bridge_name
+           @logger.info "Skipping removal of system bridge #{bridge_name}"
+           return
+        end
+
         @logger.info "Checking whether bridge #{bridge_name} exists"
         brctl_output = `ifconfig -a | grep -q #{bridge_name}`
         return if $?.to_i != 0