Add flexible Linux box support for Vagrant

Determining the SSH service restart command needed based on
the Vagrant box name containing one of the expected sequences
is problematic. With this change the required service restart
command should be automatically determined for at least all
vaguely recent Debian, Ubuntu, EL, or Suse systems, regardless
of box name.

tasks/vagrant.rb

@@ -80,16 +80,6 @@ def configure_remoting(platform, remoting_config_path, password)
     command = "vagrant ssh-config > \"#{remoting_config_path}\""
     run_local_command(command, @vagrant_env)
     remoting_config = Net::SSH::Config.load(remoting_config_path, 'default')
-    case platform
-    when %r{debian.*|ubuntu.*}
-      restart_command = 'service ssh restart'
-    when %r{sles-11.*|(centos|redhat|oracle)-[56].*}
-      restart_command = 'service sshd restart'
-    when %r{centos.*|redhat.*|oracle.*|sles.*}
-      restart_command = 'systemctl restart sshd.service'
-    else
-      raise ArgumentError, "Unsupported Platform: '#{platform}'"
-    end
     # Pre-configure sshd on the platform prior to handing back
     ssh_params = {
       port: remoting_config['port'],
@@ -104,6 +94,15 @@ def configure_remoting(platform, remoting_config_path, password)
     ) do |session|
       session.exec!('sudo su -c "cp -r .ssh /root/."')
       session.exec!('sudo su -c "sed -i \"s/.*PermitUserEnvironment\s.*/PermitUserEnvironment yes/g\" /etc/ssh/sshd_config"')
+      systemctl = session.exec!('which systemctl 2>/dev/null')
+      restart_command = if systemctl.strip.empty?
+                          # Debian and Ubuntu use 'ssh' and the EL/Suse family use 'sshd'. This will catch either.
+                          'service ssh restart || service sshd restart'
+                        else
+                          # On Debian/Ubuntu sshd is an alias to the 'ssh' service, and on the EL/Suse families
+                          # 'sshd' is the service name, so 'sshd.service' works for all:
+                          'systemctl restart sshd.service'
+                        end
       session.exec!("sudo su -c \"#{restart_command}\"")
     end
   else