From f9dd5392ff3d330bea7d0e822b1e3509a2d6d823 Mon Sep 17 00:00:00 2001
From: Fabio Rehm <fgrehm@gmail.com>
Date: Sat, 28 Sep 2013 22:37:31 -0300
Subject: [PATCH] Improve checking for support for fetching IP with
 `lxc-attach` [GH-118]

---
 lib/vagrant-lxc/action/fetch_ip_with_lxc_attach.rb | 12 +++---------
 lib/vagrant-lxc/driver/cli.rb                      |  7 ++++++-
 lib/vagrant-lxc/errors.rb                          |  2 ++
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/lib/vagrant-lxc/action/fetch_ip_with_lxc_attach.rb b/lib/vagrant-lxc/action/fetch_ip_with_lxc_attach.rb
index 45e6231..dd8641f 100644
--- a/lib/vagrant-lxc/action/fetch_ip_with_lxc_attach.rb
+++ b/lib/vagrant-lxc/action/fetch_ip_with_lxc_attach.rb
@@ -12,20 +12,14 @@ module Vagrant
 
           def call(env)
             env[:machine_ip] ||= assigned_ip(env)
-          rescue LXC::Errors::ExecuteError
-            @logger.info 'Unable to fetch IP with `lxc-attach`!'
+          rescue LXC::Errors::NamespacesNotSupported
+            @logger.info 'The `lxc-attach` command available does not support the --namespaces parameter, falling back to dnsmasq leases to fetch container ip'
           ensure
             @app.call(env)
           end
 
           def assigned_ip(env)
-            driver  = env[:machine].provider.driver
-            version = driver.version.match(/^(\d+\.\d+)\./)[1].to_f
-            unless version >= 0.8
-              @logger.debug "lxc version does not support the --namespaces argument to lxc-attach"
-              return nil
-            end
-
+            driver = env[:machine].provider.driver
             ip = ''
             retryable(:on => LXC::Errors::ExecuteError, :tries => 10, :sleep => 3) do
               unless ip = get_container_ip_from_ip_addr(driver)
diff --git a/lib/vagrant-lxc/driver/cli.rb b/lib/vagrant-lxc/driver/cli.rb
index c963ac7..71b8906 100644
--- a/lib/vagrant-lxc/driver/cli.rb
+++ b/lib/vagrant-lxc/driver/cli.rb
@@ -81,7 +81,12 @@ module Vagrant
           if cmd.last.is_a?(Hash)
             opts       = cmd.pop
             namespaces = Array(opts[:namespaces]).map(&:upcase).join('|')
-            extra      = ['--namespaces', namespaces] if namespaces
+
+            if run(:attach, '-h').include?('--namespaces')
+              extra = ['--namespaces', namespaces] if namespaces
+            else
+              raise LXC::Errors::NamespacesNotSupported
+            end
           end
 
           run :attach, '--name', @name, *((extra || []) + cmd)
diff --git a/lib/vagrant-lxc/errors.rb b/lib/vagrant-lxc/errors.rb
index e2c612f..557cbaa 100644
--- a/lib/vagrant-lxc/errors.rb
+++ b/lib/vagrant-lxc/errors.rb
@@ -6,6 +6,8 @@ module Vagrant
       class ExecuteError < Vagrant::Errors::VagrantError
         error_key(:lxc_execute_error)
       end
+      class NamespacesNotSupported < Vagrant::Errors::VagrantError
+      end
 
       class LxcNotInstalled < Vagrant::Errors::VagrantError
         error_key(:lxc_not_installed)