#!/bin/python
# Migrates the machine passed as arguments from the dev cluster.
# To be run on the prod cluster.

## The present version is NOT A REAL SCRIPT.
## Things may not even be tested.  Copy and paste.
not_ready_yet_do_not_run_me

from invirt import remctl as r
from lib import database
import subprocess
import sys

dev_db_uri = 'postgres://sipb-xen@sipb-xen-dev.mit.edu/sipb_xen'
database.connect(dev_db_uri)
dev_sess = database.session

database.connect()
prod_sess = database.session

## dump from dev db
def take_data(machine_name):
  dev_sess.begin()
  machine = dev_sess.query(database.Machine).filter_by(name=machine_name).one()
  
  # Clean out the ACL just so we don't have to think about it
  machine.acl = []
  dev_sess.update(machine)
  
  disks = machine.disks
  nics = machine.nics
  for r in disks + nics + [machine]:
    dev_sess.delete(r)
  
  dev_sess.commit()
  
  for r in disks + nics + [machine]:
    dev_sess.expunge(r)
    del r._instance_key
  
  return machine

## add to prod db
def restore_data(machine):
  # The machine's type is still the one attached to the dev database;
  # get the right one
  machine.type = prod_sess.query(database.Type).filter_by(type_id=machine.type.type_id).one()
  prod_sess.begin()
  prod_sess.save(machine)
  prod_sess.commit()
  
def migrate_vm(machine_name):
  # Power off the VM on dev
  #
  # This has to be done first, because once the machine is deleted
  # from the database, we can't remctl for it anymore
  out, err = r.remctl('xvm-remote.mit.edu', 'control', machine_name, 'destroy', err=True)
  print out
  
  machine = take_data(machine_name)
  
  ## copy disk image... copy, copy...
  for disk in machine.disks:
    lvname='d_%s_%s' % (machine.name, disk.guest_device_name)
    
    subprocess.check_call(['lvcreate', '-L%sM' % str(disk.size), '-n', lvname, 'xenvg'])
    
    ssh = subprocess.Popen(['ssh', '-o', 'GSSAPIDelegateCredentials=no',
                'torchwood-institute.mit.edu',
                'dd', 'if=/dev/xenvg/%s' % lvname, 'bs=1M'],
                 stdout=subprocess.PIPE)
    dd = subprocess.Popen(['dd', 'of=/dev/xenvg/%s' % lvname, 'bs=1M'],
                stdin=ssh.stdout)
    dd.wait()
  
  restore_data(machine)

if __name__ == '__main__':
  for vm in sys.argv[1:]:
    print '==============================================='
    print 'Migrating %s' % vm
    print '==============================================='
    migrate_vm(vm.strip())