Query host interfaces directly as libvirt may not include them (#1627)

On some distros the libvirt does not appear to always return all of the
host interfaces. Switch to using 'ip -j link show' to read them directly
from the system in order to ensure all devices are read.

Refactor the driver tests to better isolate between test setup for the
different sets of functions and avoid accidental setting of
configuration details that may not be obvious.

Fixes: #1624

lib/vagrant-libvirt/action/forward_ports.rb

@@ -110,7 +110,7 @@ module VagrantPlugins
               end
           ).map { |s| ['-o', s] }.flatten
 
-          options += ['-o', "ProxyCommand=\"#{ssh_info[:proxy_command]}\""] if machine.provider_config.proxy_command
+          options += ['-o', "ProxyCommand=\"#{ssh_info[:proxy_command]}\""] if machine.provider_config.proxy_command && !machine.provider_config.proxy_command.empty?
 
           ssh_cmd = ['ssh'] + options + params
 

lib/vagrant-libvirt/config.rb

@@ -19,6 +19,7 @@ module VagrantPlugins
 
       # The name of the server, where Libvirtd is running.
       attr_accessor :host
+      attr_accessor :port
 
       # If use ssh tunnel to connect to Libvirt.
       attr_accessor :connect_via_ssh
@@ -1218,14 +1219,9 @@ module VagrantPlugins
       end
 
       def host_devices(machine)
-        @host_devices ||= begin
-          (
-            machine.provider.driver.list_host_devices.map { |iface| iface.name } +
-            machine.provider.driver.list_networks.map { |net| net.bridge_name }
-          ).uniq.select do |dev|
-            next if dev.empty?
-            dev != "lo" && !@host_device_exclude_prefixes.any? { |exclude| dev.start_with?(exclude) }
-          end
+        machine.provider.driver.host_devices.select do |dev|
+          next if dev.empty?
+          dev != "lo" && !@host_device_exclude_prefixes.any? { |exclude| dev.start_with?(exclude) }
         end
       end
 

lib/vagrant-libvirt/driver.rb

@@ -197,12 +197,28 @@ module VagrantPlugins
         domain
       end
 
-      def list_host_devices
-        connection.client.list_all_interfaces
-      end
+      def host_devices
+        @host_devices ||= begin
+          cmd = []
+          unless @machine.provider_config.proxy_command.nil? || @machine.provider_config.proxy_command.empty?
+            cmd = ['ssh', @machine.provider_config.host]
+            cmd += ['-p', @machine.provider_config.port.to_s] if @machine.provider_config.port
+            cmd += ['-l', @machine.provider_config.username] if @machine.provider_config.username
+            cmd += ['-i', @machine.provider_config.id_ssh_key_file] if @machine.provider_config.id_ssh_key_file
+          end
+          ip_cmd = cmd + %W(ip -j link show)
 
-      def list_networks
-        connection.client.list_all_networks
+          result = Vagrant::Util::Subprocess.execute(*ip_cmd)
+          raise Errors::FogLibvirtConnectionError unless result.exit_code == 0
+
+          info = JSON.parse(result.stdout)
+
+          (
+            info.map { |iface| iface['ifname'] } +
+            connection.client.list_all_interfaces.map { |iface| iface.name } +
+            connection.client.list_all_networks.map { |net| net.bridge_name }
+          ).uniq.reject(&:empty?)
+        end
       end
 
       def attach_device(xml)

lib/vagrant-libvirt/provider.rb

@@ -70,7 +70,7 @@ module VagrantPlugins
           forward_x11: @machine.config.ssh.forward_x11
         }
 
-        ssh_info[:proxy_command] = @machine.provider_config.proxy_command if @machine.provider_config.proxy_command
+        ssh_info[:proxy_command] = @machine.provider_config.proxy_command if @machine.provider_config.proxy_command && !@machine.provider_config.proxy_command.empty?
 
         ssh_info
       end