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#!/usr/bin/env python
# -*- coding: utf-8 -*-
import pymongo
import sys
import inspect
import kpov_random_helpers
import settings
import guestfs
import os
import glob
import subprocess
import fcntl
def get_prepare_disks(db, task_id):
prepare_disks_source = db.prepare_disks.find_one({'task_id':task_id})['source']
prepare_disks_code = compile(prepare_disks_source, 'prepare_disks.py', 'exec')
exec(prepare_disks_code)
return prepare_disks
def create_snapshot(task_id, student_id, disk_name, overwrite = True, cow = False):
print(os.path.join(settings.DISK_TEMPLATE_PATH, task_id, disk_name) + '.*')
template_paths = glob.glob(os.path.join(settings.DISK_TEMPLATE_PATH, task_id, disk_name) + '.*')
filtered_paths = filter((lambda x: os.path.splitext(x)[1] == '.' + settings.STUDENT_DISK_FORMAT), template_paths)
if filtered_paths:
template_path = filtered_paths[0]
else:
template_path = template_paths[0]
if cow:
d = os.path.join(student_id, task_id, disk_name) + os.path.splitext(template_path)[1]
else:
d = os.path.join(student_id, task_id, disk_name) + '.qcow2'
try:
os.makedirs(os.path.join(settings.STUDENT_DISK_PATH, student_id, task_id))
except:
pass
disk_file = os.path.join(settings.STUDENT_DISK_PATH, d)
if overwrite or not os.path.exists(disk_file):
if cow:
subprocess.call(['cp', '--reflink=always', template_path, disk_file])
else:
subprocess.call(['qemu-img', 'create', '-f', 'qcow2', '-o', 'backing_file=' + template_path,
disk_file])
return d
def publish_snapshot(d):
if os.path.splitext(d)[1][1:] != settings.STUDENT_DISK_FORMAT:
snap_name = os.path.splitext(d)[0] + '.' + settings.STUDENT_DISK_FORMAT
disk_file = os.path.join(settings.STUDENT_DISK_PATH, d)
snap_file = os.path.join(settings.STUDENT_DISK_PATH, snap_name)
subprocess.call(['qemu-img', 'convert', '-f', 'qcow2', '-O', settings.STUDENT_DISK_FORMAT, disk_file,
snap_file])
url = settings.STUDENT_DISK_URL + snap_name
else:
url = settings.STUDENT_DISK_URL + d
return url
if __name__ == '__main__':
if len(sys.argv) != 1:
print "Usage: {0}"
print "Create the neccessarry disk images"
db = pymongo.Connection(settings.DB_HOST).kpov
try:
db.authenticate(settings.USERNAME, settings.PASSWORD)
except Exception, e:
print str(e)
dev_prefix = settings.GUESTFS_DEV_PREFIX
l = db.student_computers.find({"disk_urls": {"$exists": False}})
computers_by_task_student = dict()
for computer in l:
student_id, task_id = computer['student_id'], computer['task_id']
if (task_id, student_id) not in computers_by_task_student:
computers_by_task_student[(task_id, student_id)] = list()
computers_by_task_student[(task_id, student_id)].append(computer)
for (task_id, student_id), computers in computers_by_task_student.iteritems():
l = db.student_computers.find_one({'task_id': task_id, 'student_id':student_id, "disk_urls": {"$exists": False}})
if l is None:
continue
lock_file = os.path.join(settings.STUDENT_LOCKFILE_PATH,
'{0}-{1}.lock'.format(student_id, task_id))
lock_fp = open(lock_file, 'w')
try:
fcntl.lockf(lock_fp, fcntl.LOCK_EX | fcntl.LOCK_NB)
except IOError:
continue
params = db.task_params.find_one({'task_id': task_id, 'student_id': student_id})['params']
prepare_disks = get_prepare_disks(db, task_id)
# tule odpri, ustvari snapshote za vajo
templates = dict()
all_disks = dict()
parts = dict()
for computer in computers:
lock_fp.write('creating computer ' + computer['name'] + '\n')
all_disks[computer['name']] = dict()
manual_disks = list()
this_computers_disks = set()
try_automount = False
g = guestfs.GuestFS()
for disk in computer['disks']:
lock_fp.write("register " + disk['name'] + '\n')
snap = create_snapshot(task_id, student_id, disk['name'],
cow = settings.STUDENT_DISK_COW)
snap_file = os.path.join(settings.STUDENT_DISK_PATH, snap)
if 'options' in disk:
g.add_drive_opts(snap_file, **(disk['options']))
else:
g.add_drive(snap_file)
if 'parts' in disk:
for p in disk['parts']:
manual_disks.append((dev_prefix + p['dev'],
p['path'], p.get('options', None)))
else:
try_automount = True
templates[disk['name']] = g
all_disks[computer['name']][disk['name']] = snap
g.launch()
mounted = set()
if try_automount:
roots = g.inspect_os()
for root in roots:
mps = g.inspect_get_mountpoints(root)
lock_fp.write("detected:"+str(mps)+'\n')
for mountpoint, device in sorted(mps):
if mountpoint not in mounted:
try:
g.mount(device, mountpoint, )
lock_fp.write( 'mounted ' + device + ' on ' + mountpoint + '\n')
except RuntimeError as msg:
lock_fp.write( "%s (ignored)\n" % msg)
mounted.add(mountpoint)
for device, mountpoint, opts in manual_disks:
try:
if opts is not None:
g.mount_options(opts, device, mountpoint)
else:
g.mount(device, mountpoint)
lock_fp.write('manually mounted ' + device + " on " + mountpoint + '\n')
except RuntimeError as msg:
lock_fp.write( "%s (ignored)\n" % msg)
lock_fp.write("preparing disks\n")
prepare_disks(templates, params)
# pospravi za seboj.
lock_fp.write("unmounting\n")
for g in set(templates.values()):
g.umount_all()
g.close()
lock_fp.write("saving URLs\n")
for comp_name, d_dict in all_disks.iteritems():
disk_urls = list()
for d_name, d in d_dict.iteritems():
lock_fp.write('publishing '+ str(d) + '\n')
url = publish_snapshot(d)
lock_fp.write('published as '+ url + '\n')
disk_urls.append({'name': d_name, 'url': url})
lock_fp.write('urls: '+ str(disk_urls) + '\n')
l = db.student_computers.update({
"disk_urls": {"$exists": False},
'student_id': student_id,
'task_id': task_id,
'name': comp_name},
{'$set': { 'disk_urls': disk_urls }})
# print "done for ", student_id, task_id
os.unlink(lock_file)
lock_fp.close()
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