Launch improvements.

* launch/README: Add note on enabling puppet agent for non-slave
CentOS servers.

* launch/launch-node.py: Reboot immediately after puppeting so that
we don't leave the server booted on an old/vulnerable kernel.

Change-Id: I5d0d36c2a11b078321a8715985868422946b06cb

launch/README

@@ -62,10 +62,15 @@ If this is a Jenkins slave, Puppet configuration is applied through
 an already installed cron job, so you can ignore this section. If
 this is ''not'' a Jenkins slave, you'll want to log into it via SSH
 and turn on the Puppet agent so it will start checking into the
-master on its own::
+master on its own. on Debian/Ubuntu::
 
   sudo sed -i 's/^START=.*/START=yes/' /etc/default/puppet
   sudo invoke-rc.d puppet start
 
+...or on CentOS/Fedora/RHEL::
+
+  sudo chkconfig puppet on
+  sudo service puppet start
+
 You should be able to tell from the Puppet Dashboard when it begins
 to check in, which normally happens at 10-minute intervals.

launch/launch-node.py

@@ -120,6 +120,8 @@ def bootstrap_server(server, admin_pass, key, cert, environment, name,
                    "--no-daemonize --verbose --onetime --pluginsync true "
                    "--certname %s" % (environment, certname))
 
+    ssh_client.ssh("reboot")
+
 def build_server(client, name, image, flavor, cert, environment):
     key = None
     server = None