# Xen domain configuration file for scripts.mit.edu virtualized web servers
#
# usage, e.g.:
#   xm create scripts-server machine_name=bees-knees
#   xm create scripts-server machine_name=cats-whiskers
# name is the name of the server (as used in the LV volumes)
# mac5 is the fifth octet of the MAC address: ac:de:48:00:xx:01
# set install=fcX if you want to run a Fedora install, where X
# is the version of Fedora to install

vm_host = 0
vm_cpus = 1
vm_mem  = 2
vm_mac5 = 3
machines = { 'bees-knees'     : ['david-letterman',  2, 2560, '10'],
             'cats-whiskers'  : ['david-letterman',  2, 6144, '20'],
             'not-backward'   : ['david-letterman',  2, 2560, '30'],
             'busy-beaver'    : ['conan-obrien',     2, 4096, '40'],
             'pancake-bunny'  : ['conan-obrien',     2, 4096, '50'],
             'whole-enchilada': ['jay-leno',         2, 4096, '60'],
             'real-mccoy'     : ['jay-leno',         2, 4096, '70'],
             'not-forward'    : ['jay-leno',         1,  512, '80'],
             'old-faithful'   : ['johnny-carson',    2, 4096, '90'],
             'better-mousetrap' : ['johnny-carson',  2, 4096, 'a0'],
             'shining-armor'  : ['david-letterman',  2, 6144, 'b0'],
           }
vm = machines[machine_name]

mac5 = vm[vm_mac5]

def maybe_download_isolinux(install):
  """
  Download the release image if it isn't already in /root.
  """
  import subprocess
  import os.path

  install_dir = "/root/%s-install" % install
  if os.path.exists(install_dir): return
  print "Downloading %s..." % install_dir
  fedora_release = install[1:],
  download_dir = "ftp://mirrors.mit.edu/fedora/linux/releases/%s/Fedora/x86_64/os/isolinux" % fedora_release
  os.mkdir(install_dir)
  subprocess.check_call(["wget", "-r", "-nd", download_dir], cwd=install_dir)

def serve_kickstart(machine_name, install):
  """
  Serve a parametrized /root/kickstart.ks to localhost once.
  """
  import socket
  import string
  import re
  import os
  import BaseHTTPServer
  import sys

  # some calculations
  hostname = machine_name + ".mit.edu"
  ip = socket.gethostbyname(hostname)

  source_server = "shining-armor.mit.edu" # hard-coded
  source_ip = re.sub('^18.181.0.', '172.21.0.', socket.gethostbyname(source_server))

  # generate the kickstart file
  ks_orig = open("/etc/xen/scripts.ks").read()
  ks = string.Template(ks_orig).substitute(
    local_mirror = "ftp://mirrors.mit.edu",
    official_mirror = "http://download3.fedora.redhat.com/pub",
    arch = "x86_64",
    fedora_release = re.sub('^f', '', install),
    hostname = hostname,
    ip = ip,
    backend_ip = re.sub('^18.181.0.', '172.21.0.', ip),
    branch = "branches/fc13-dev",
    source_server = source_server,
    source_ip = source_ip,
    )

  class SingleFileHandler(BaseHTTPServer.BaseHTTPRequestHandler):
    def do_GET(self):
      self.send_response(200)
      self.end_headers()
      self.wfile.write(ks)

  if os.fork(): return

  # brief race condition
  try:
    BaseHTTPServer.HTTPServer(('', 55555), SingleFileHandler).handle_request()
  except Exception, e:
    print "Serving kickstart failed."
    print e
  else:
    print "Kickstart served"

  sys.exit()

if 'install' in locals():
  maybe_download_isolinux(install)

  kernel = "/root/%s-install/vmlinuz" % install
  ramdisk = "/root/%s-install/initrd.img" % install

  ip = socket.gethostbyname(machine_name + ".mit.edu")

  serve_kickstart(machine_name, install)

  ks_url = "http://%s.mit.edu:55555/" % vm[vm_host]
  extra = ' '.join([
      "selinux=0",
      "ks=" + ks_url,
      "ip=" + ip,
      "netmask=255.255.0.0",
      "gateway=18.181.0.1",
      "dns=18.70.0.160,18.71.0.151,18.72.0.3",
      "ksdevice=eth0",
      # "syslog=18.181.0.51:514 debug=1 loglevel=debug telnet",
      ])
  on_reboot = 'destroy' # don't rerun the installer

elif 'type' in locals() and type == 'hvm':
  kernel = "/usr/lib/xen/boot/hvmloader"
  builder = "hvm"
  vnc = 1
  vncpassword = "foobar"
else:
  # Fedora installs GRUB.
  bootloader = "/usr/bin/pygrub"

vcpus = vm[vm_cpus]
if 'memory' not in locals(): memory = vm[vm_mem]
maxmem = 16384
name = machine_name
vg = vm[vm_host]
disk = [i % (vg, name) for i in ['phy:/dev/%s/%s-root,xvda,w',
                                 'phy:/dev/%s/%s-swap,xvde,w']]
vif = [i % mac5 for i in ['bridge=eth0, mac=ac:de:48:00:%s:01',
                          'bridge=eth1, mac=ac:de:48:00:%s:02']]

if 'builder' not in locals() or builder != "hvm":
  # https://bugzilla.redhat.com/show_bug.cgi?id=466681
  # pygrub uses cached and eventually outdated grub.conf, kernel and initrd
  file('/proc/sys/vm/drop_caches', 'w').write('1')

#if 'install' in locals():
#  disk.append('file:/root/%s-install/cdimg.ext3.img,hdc1,r' % install)