Use HTTP to download kernel and initital RAM disk

As of version 3.70 (Fuel uses 4.05) pxelinux can download files
via HTTP.

DHCP option 210 sets prefix for all files that pxelinux downloads.

Change-Id: I26b62414e1cc0193c75f954ed7ed76570a4bf2f6
Doc-Impact: ops-guide
Closes-Bug: 1521759

deployment/puppet/cobbler/manifests/server.pp

@@ -199,6 +199,15 @@ class cobbler::server (
     notify  => Service[$cobbler_web_service],
   }
 
+  file { '/etc/httpd/conf.d/cobbler-tftp.conf':
+    content => template('cobbler/cobbler-tftp.conf.erb'),
+    owner   => 'root',
+    group   => 'root',
+    mode    => '0644',
+    require => File['/etc/httpd/conf.d/'],
+    notify  => Service[$cobbler_web_service],
+  }
+
   service { $cobbler_web_service:
     ensure     => running,
     enable     => true,

deployment/puppet/cobbler/templates/cobbler-tftp.conf.erb

@@ -0,0 +1,6 @@
+Alias /cobbler/boot /var/lib/tftpboot
+
+<Directory /var/lib/tftpboot>
+  Options +Indexes +FollowSymLinks
+  Require all granted
+</Directory>

deployment/puppet/nailgun/templates/dnsmasq.dhcp-range.erb

@@ -2,3 +2,4 @@
 dhcp-range=<%= @range_name %>,<%= @dhcp_start_address %>,<%= @dhcp_end_address %>,<%= @dhcp_netmask %>,<%= @lease_time %>
 dhcp-option=net:<%= @range_name %>,option:router,<%= @dhcp_gateway %>
 dhcp-boot=net:<%= @range_name %>,pxelinux.0,boothost,<%= @next_server %>
+dhcp-option-force=210,http://<%= @next_server %>/cobbler/boot/