From a4768c26ca33f6ce7dbe0360e69c4bf9d5e44f2e Mon Sep 17 00:00:00 2001
From: Kristof Willaert <kristof.willaert@cegeka.be>
Date: Tue, 3 Jun 2014 17:53:26 +0200
Subject: [PATCH] Add fallback mechanism for platforms without attach support

Some platforms (most notably CentOS and RHEL) use a kernel without
'attach' support. This patch detects this absence and falls back
to the alternative ways of doing things like detection of IP address
and halting the container.
It does so by running the command "true" through lxc-attach.
---
 lib/vagrant-lxc/action.rb     | 10 ++++++++--
 lib/vagrant-lxc/driver.rb     |  4 ++++
 lib/vagrant-lxc/driver/cli.rb | 15 ++++++++++++++-
 3 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/lib/vagrant-lxc/action.rb b/lib/vagrant-lxc/action.rb
index 66269cc..19dae69 100644
--- a/lib/vagrant-lxc/action.rb
+++ b/lib/vagrant-lxc/action.rb
@@ -197,8 +197,14 @@ module Vagrant
       def self.action_fetch_ip
         Builder.new.tap do |b|
           b.use Builtin::ConfigValidate
-          b.use FetchIpWithLxcAttach
-          b.use FetchIpFromDnsmasqLeases
+          b.use Builtin::Call, Builtin::IsState, :running do |env, b2|
+            if env[:result]
+              b2.use FetchIpWithLxcAttach if env[:machine].provider.driver.supports_attach?
+              b2.use FetchIpFromDnsmasqLeases
+            else
+              b2.use Builtin::Message, I18n.t("vagrant_lxc.messages.not_running")
+            end
+          end
         end
       end
 
diff --git a/lib/vagrant-lxc/driver.rb b/lib/vagrant-lxc/driver.rb
index 6435c24..9ae5662 100644
--- a/lib/vagrant-lxc/driver.rb
+++ b/lib/vagrant-lxc/driver.rb
@@ -113,6 +113,10 @@ module Vagrant
         @cli.destroy
       end
 
+      def supports_attach?
+        @cli.supports_attach?
+      end
+
       def attach(*command)
         @cli.attach(*command)
       end
diff --git a/lib/vagrant-lxc/driver/cli.rb b/lib/vagrant-lxc/driver/cli.rb
index d04a1d9..b9f6ee3 100644
--- a/lib/vagrant-lxc/driver/cli.rb
+++ b/lib/vagrant-lxc/driver/cli.rb
@@ -77,7 +77,7 @@ module Vagrant
         end
 
         def stop
-          attach '/sbin/halt'
+          attach '/sbin/halt' if supports_attach?
           run :stop, '--name', @name
         end
 
@@ -126,6 +126,19 @@ module Vagrant
           end
         end
 
+        def supports_attach?
+          unless defined?(@supports_attach)
+            begin
+              @supports_attach = true
+              run(:attach, '--name', @name, 'true')
+            rescue LXC::Errors::ExecuteError
+              @supports_attach = false
+            end
+          end
+
+          return @supports_attach
+        end
+
         private
 
         def run(command, *args)