action/fetch_ip_with_lxc_attach: Attach to the MOUNT namespace in order to fix GH-300

CHANGELOG.md

@@ -8,10 +8,13 @@ IMPROVEMENTS:
 
 BUG FIXES:
 
+  - Attach to containers using the `MOUNT` namespace when attempting to fetch
+    container's IP [[GH-300]]
   - Escape space characters for synced folders [[GH-291]]
   - Use Vagrant's ruby on the sudoers file so that it works on systems that don't
     have a global ruby installation [[GH-289]]
 
+[GH-300]: https://github.com/fgrehm/vagrant-lxc/issues/300
 [GH-291]: https://github.com/fgrehm/vagrant-lxc/issues/291
 [GH-289]: https://github.com/fgrehm/vagrant-lxc/issues/289
 

lib/vagrant-lxc/action/fetch_ip_with_lxc_attach.rb

@@ -32,7 +32,7 @@ module Vagrant
 
         # From: https://github.com/lxc/lxc/blob/staging/src/python-lxc/lxc/__init__.py#L371-L385
         def get_container_ip_from_ip_addr(driver)
-          output = driver.attach '/sbin/ip', '-4', 'addr', 'show', 'scope', 'global', 'eth0', namespaces: 'network'
+          output = driver.attach '/sbin/ip', '-4', 'addr', 'show', 'scope', 'global', 'eth0', namespaces: ['network', 'mount']
           if output =~ /^\s+inet ([0-9.]+)\/[0-9]+\s+/
             return $1.to_s
           end