From 1761e65f2682b2aa0e459565c35ef5cbca672442 Mon Sep 17 00:00:00 2001
From: Brian Cain <bcain@hashicorp.com>
Date: Tue, 23 Oct 2018 10:17:39 -0700
Subject: [PATCH] Fixes #9763 #10300: Fall back on ifdown/ifup tools for
 network restart

This commit adds some additional logic that falls back to using the
ifdown/ifup tools to restart networking. On Ubuntu 14.04, the init
script was designed to always fail to restart newtorking, so it needs
to use the ifdown/up tools instead. This commit will use the networking
init script as a last resort to restart networking, assuming other
commands haven't broken networking already.

https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/1301015
---
 plugins/guests/debian/cap/change_host_name.rb | 21 ++++++++++++++++--
 .../debian/cap/change_host_name_test.rb       | 22 ++++++++++++++++---
 2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/plugins/guests/debian/cap/change_host_name.rb b/plugins/guests/debian/cap/change_host_name.rb
index d8a127100..2323734bd 100644
--- a/plugins/guests/debian/cap/change_host_name.rb
+++ b/plugins/guests/debian/cap/change_host_name.rb
@@ -1,3 +1,5 @@
+require "log4r"
+
 module VagrantPlugins
   module GuestDebian
     module Cap
@@ -6,6 +8,7 @@ module VagrantPlugins
         extend Vagrant::Util::GuestInspection::Linux
 
         def self.change_host_name(machine, name)
+          @logger = Log4r::Logger.new("vagrant::guest::debian::changehostname")
           comm = machine.communicate
 
           if !comm.test("hostname -f | grep '^#{name}$'", sudo: false)
@@ -44,16 +47,30 @@ module VagrantPlugins
               EOH
             end
 
-            restart_command = "/etc/init.d/networking restart"
+            init_restart_command = "/etc/init.d/networking restart"
+            ifdownup_restart_command = "ifdown --exclude=lo -a && ifup --exclude=lo -a"
+            systemctl_restart_command = "systemctl stop ifup@eth0.service && systemctl start ifup@eth0.service"
 
+            restart_command = ifdownup_restart_command
             if systemd?(comm)
               if systemd_networkd?(comm)
+                @logger.debug("Attempting to restart networking with systemd-networkd")
                 restart_command = "systemctl restart systemd-networkd.service"
               elsif systemd_controlled?(comm, "NetworkManager.service")
+                @logger.debug("Attempting to restart networking with NetworkManager")
                 restart_command = "systemctl restart NetworkManager.service"
+              else
+                @logger.debug("Attempting to restart networking with ifup@.service")
+                restart_command = systemctl_restart_command
               end
+            else
+              @logger.debug("Attempting to restart networking with ifdown/ifup net tools")
+            end
+
+            if !comm.test(restart_command, sudo: true)
+              @logger.debug("Attempting to restart networking with init networking service")
+              comm.sudo(init_restart_command)
             end
-            comm.sudo(restart_command)
           end
         end
       end
diff --git a/test/unit/plugins/guests/debian/cap/change_host_name_test.rb b/test/unit/plugins/guests/debian/cap/change_host_name_test.rb
index 73a70564c..b5a319185 100644
--- a/test/unit/plugins/guests/debian/cap/change_host_name_test.rb
+++ b/test/unit/plugins/guests/debian/cap/change_host_name_test.rb
@@ -80,10 +80,17 @@ describe "VagrantPlugins::GuestDebian::Cap::ChangeHostName" do
       context "when networkd and NetworkManager are not in use" do
         let(:networkd) { false }
         let(:network_manager) { false }
+        let(:systemd) { true }
 
-        it "restarts the network using service" do
+        it "restarts the network using systemctl" do
           cap.change_host_name(machine, name)
-          expect(comm.received_commands[3]).to match(/networking restart/)
+          expect(comm.received_commands[3]).to match(/systemctl stop ifup/)
+        end
+
+        it "restarts networking with networking init script" do
+          comm.stub_command("systemctl stop ifup@eth0.service && systemctl start ifup@eth0.service", exit_code: 1)
+          cap.change_host_name(machine, name)
+          expect(comm.received_commands[4]).to match(/networking restart/)
         end
       end
 
@@ -91,8 +98,17 @@ describe "VagrantPlugins::GuestDebian::Cap::ChangeHostName" do
         let(:systemd) { false }
 
         it "restarts the network using service" do
+          comm.stub_command("systemctl stop ifup@eth0.service && systemctl start ifup@eth0.service", exit_code: 1)
           cap.change_host_name(machine, name)
-          expect(comm.received_commands[3]).to match(/networking restart/)
+          expect(comm.received_commands[4]).to match(/networking restart/)
+        end
+
+        it "restarts the network using ifdown/ifup" do
+          comm.stub_command("systemctl stop ifup@eth0.service && systemctl start ifup@eth0.service", exit_code: 1)
+          comm.stub_command("/etc/init.d/networking restart", exit_code: 1)
+          cap.change_host_name(machine, name)
+          expect(comm.received_commands[4]).to match(/ifdown/)
+          expect(comm.received_commands[4]).to match(/ifup/)
         end
       end
     end