Set up a DNS entry for Hydra on the public domain

test/Vagrantfile

@@ -16,12 +16,19 @@ Vagrant.configure(API_VERSION) do |config|
     vb.customize ["guestproperty", "set", :id, "/VirtualBox/GuestAdd/VBoxService/--timesync-set-threshold", 3000]
   end
 
+  # Setup /etc/hosts.
+  #
+  # Hosts need to find each other using both the short name and the
+  # fqdn. Furthermore, the OAuth workflow (even internally) uses the
+  # public domain, so we also create an entry for that, pointing at a
+  # random node.
   config.vm.provision "shell", inline: <<SCRIPT
 cat > /etc/hosts <<EOF
 127.0.0.1 localhost
 192.168.10.10 node1.#{DOMAIN} node1
 192.168.10.11 node2.#{DOMAIN} node2
 192.168.10.12 node3.#{DOMAIN} node3
+192.168.10.12 hydra.public.#{DOMAIN}
 EOF
 SCRIPT