X-Git-Url: http://xvm.mit.edu/gitweb/invirt/packages/invirt-images.git/blobdiff_plain/19c32ff14f08ddcb9826c7738ad0163a5c9a6b39..5b86bc14d1bf12e03968370fac49aa0087811e45:/invirt-images diff --git a/invirt-images b/invirt-images index 1566cc6..1e77767 100755 --- a/invirt-images +++ b/invirt-images @@ -1,135 +1,90 @@ -#!/usr/bin/python +#!/usr/bin/env python3 -from invirt import database import os import subprocess import random import string import tempfile -import urllib +import urllib.request import math -import optparse as op - -class InvirtImageException(Exception): - pass +import argparse -# verbosity = 0 means no output from the actual commands -# verbosity = 1 means only errors from the actual commands -# verbosity = 2 means all output from the actual commands -verbosity = 0 +from invirt import database -def getOutput(): - global verbosity - return { - 'stdout': subprocess.PIPE if verbosity < 2 else None, - 'stderr': subprocess.PIPE if verbosity < 1 else None - } def lvcreate(name, size): - lvc = subprocess.Popen(['lvcreate', '-L', size, '-n', name, 'xenvg'], - stderr=subprocess.PIPE, - stdout=getOutput()['stdout']) - if not lvc.wait(): - return 0 - stderr = lvc.stderr.read() - if 'already exists in volume group' in stderr: - return 5 - else: - if verbosity > 0: - print stderr - return 6 + subprocess.run(['lvcreate', '-L', size, '-n', name, 'xenvg'], + check_output=True, encoding='utf-8', check=True) def lvrename(dest, src): - lvr = subprocess.Popen(['lvrename', 'xenvg', src, dest], - stderr=subprocess.PIPE, - stdout=getOutput()['stdout']) - ret = lvr.wait() - if not ret: - return 0 - stderr = lvr.stderr.read() - if 'not found in volume group' in stderr: - return 0 - else: - if verbosity > 0: - print stderr - return ret + subprocess.run(['lvchange', '-an', f'xenvg/{src}'], + check_output=True, encoding='utf-8', check=True) + + subprocess.run(['lvrename', f'xenvg/{src}', f'xenvg/{dest}'], + check_output=True, encoding='utf-8', check=True) + + subprocess.run(['lvchange', '-ay', f'xenvg/{dest}'], + check_output=True, encoding='utf-8', check=True) def lv_random(func, pattern, *args): """ - Run some LVM-related command, optionally with a random string in - the LV name. - + Run some LVM-related command with a random string in the LV name. + func takes an LV name plus whatever's in *args and returns the return code of some LVM command, such as lvcreate or lvrename - - pattern can contain at most one '%s' pattern, which will be - replaced by a 6-character random string. - - If pattern contains a '%s', the script will attempt to re-run - itself if the error code indicates that the destination already - exists + + pattern must contain one '{}' pattern, which will be replaced + by a 6-character random string. + + the script will attempt to re-run itself if the error code + indicates that the destination already exists """ + # Keep trying until it works while True: - rand_string = ''.join(random.choice(string.ascii_letters) \ - for i in xrange(6)) - if '%s' in pattern: - name = pattern % rand_string - else: - name = pattern - ret = func(name, *args) - if ret == 0: - return name - # 5 is the return code if the destination already exists - elif '%s' not in pattern or ret != 5: - raise InvirtImageException, 'E: Error running %s with args %s' % (func.__name__, args) + letters = (random.choice(string.ascii_letters) for _ in range(6)) + rand_string = ''.join(letters) -def lvcreate_random(pattern, size): - """ - Creates an LV, optionally with a random string in the name. - - Call with a string formatting pattern with a single '%s' to use as - a pattern for the name of the new LV. - """ - return lv_random(lvcreate, pattern, size) + name = pattern.format(rand_string) -def lvrename_random(src, pattern): - """ - Rename an LV to a new name with a random string incorporated. - - Call with a string formatting pattern with a single '%s' to use as - a pattern for the name of the new LV - """ - return lv_random(lvrename, pattern, src) + try: + func(name, *args) + except subprocess.CalledProcessError as e: + # 5 is the return code if the destination already exists + if e.returncode != 5: + raise + else: + return name def fetch_image(cdrom): """ Download a cdrom from a URI, shelling out to rsync if appropriate and otherwise trying to use urllib """ + full_uri = os.path.join(cdrom.mirror.uri_prefix, cdrom.uri_suffix) temp_file = tempfile.mkstemp()[1] + print(f'Fetching image {cdrom.cdrom_id} from {full_uri} to {temp_file}') try: if full_uri.startswith('rsync://'): - if subprocess.call(['rsync', '--no-motd', '-tLP', full_uri, temp_file], - **getOutput()): - raise InvirtImageException, "E: Unable to download '%s'" % full_uri + subprocess.run(['rsync', '--no-motd', '-tLP', full_uri, temp_file], + check_output=True, encoding='utf-8', check=True) else: # I'm not going to look for errors here, because I bet it'll # throw its own exceptions - urllib.urlretrieve(full_uri, temp_file) + urllib.request.urlretrieve(full_uri, temp_file) return temp_file except: - os.unlink(temp_file) + os.remove(temp_file) raise def copy_file(src, dest): """ Copy a file from one location to another using dd """ - if subprocess.call(['dd', 'if=%s' % src, 'of=%s' % dest, 'bs=1M'], - **getOutput()): - raise InvirtImageException, 'E: Unable to transfer %s into %s' % (src, dest) + + subprocess.run(['dd', f'if={src}', f'of={dest}', 'bs=1M'], + check_output=True, encoding='utf-8', check=True) def load_image(cdrom): """ @@ -137,121 +92,113 @@ def load_image(cdrom): transferring it into an LV, moving the old LV out of the way and the new LV into place """ + if cdrom.mirror_id is None: return + temp_file = fetch_image(cdrom) + + st_size = os.stat(temp_file).st_size + + assert st_size > 0, 'CD-ROM image size is 0' + + megabytes = math.ceil((float(st_size) / (1024 * 1024))) + cdrom_size = f'{megabytes}M' + try: - cdrom_size = '%sM' % math.ceil((float(os.stat(temp_file).st_size) / (1024 * 1024))) - new_lv = lvcreate_random('image-new_%s_%%s' % cdrom.cdrom_id, cdrom_size) - copy_file(temp_file, '/dev/xenvg/%s' % new_lv) - lvrename_random('image_%s' % cdrom.cdrom_id, 'image-old_%s_%%s' % cdrom.cdrom_id) - lvrename_random(new_lv, 'image_%s' % cdrom.cdrom_id) + new_lv = lv_random(lvcreate, f'image-new_{cdrom.cdrom_id}' + '_{}', cdrom_size) + copy_file(temp_file, f'/dev/xenvg/{new_lv}') + lv_random(lvrename, f'image-old_{cdrom.cdrom_id}' + '_{}', 'image_{cdrom.cdrom_id}') + lv_random(lvrename, f'image_{cdrom.cdrom_id}', new_lv) reap_images() finally: - os.unlink(temp_file) + os.remove(temp_file) def reap_images(): """ Remove stale cdrom images that are no longer in use - + load_image doesn't attempt to remove the old image because it might still be in use. reap_images attempts to delete any LVs starting with 'image-old_', but ignores errors, in case they're still being used. """ - lvm_list = subprocess.Popen(['lvs', '-o', 'lv_name', '--noheadings'], - stdout=subprocess.PIPE, - stdin=subprocess.PIPE) - lvm_list.wait() - - for lv in map(str.strip, lvm_list.stdout.read().splitlines()): + + lvm_list = subprocess.run(['lvs', '-o', 'lv_name', '--noheadings'], + check_output=True, encoding='utf-8', check=True) + + for lv in (s.strip() for s in lvm_list.stdout.readlines()): if lv.startswith('image-old_'): - subprocess.call(['lvchange', '-a', 'n', '/dev/xenvg/%s' % lv], - **getOutput()) - subprocess.call(['lvchange', '-a', 'n', '/dev/xenvg/%s' % lv], - **getOutput()) - subprocess.call(['lvchange', '-a', 'ey', '/dev/xenvg/%s' % lv], - **getOutput()) - subprocess.call(['lvremove', '--force', '/dev/xenvg/%s' % lv], - **getOutput()) + subprocess.run(['lvchange', '-a', 'n', f'/dev/xenvg/{lv}']) + subprocess.run(['lvchange', '-a', 'n', f'/dev/xenvg/{lv}']) + subprocess.run(['lvchange', '-a', 'ey', f'/dev/xenvg/{lv}']) + subprocess.run(['lvremove', '--force', f'/dev/xenvg/{lv}']) + +def action_add_cdrom(args): + attrs = {key: vars(args)[key] for key in ('cdrom_id', 'description', 'mirror_id', 'uri_suffix')} + + cdrom = database.CDROM(**attrs) + database.session.add(cdrom) + database.session.commit() + + load_image(cdrom) + +def action_add_mirror(args): + attrs = {key: vars(args)[key] for key in ('mirror_id', 'uri_prefix')} + + mirror = database.Mirror(**attrs) + database.session.add(mirror) + database.session.commit() + +def action_update(args): + if not args.names: + images = database.CDROM.query().all() + else: + images = [database.CDROM.query().get(arg) for arg in args.names] + + for cdrom in images: + if cdrom is not None: + load_image(cdrom) + +def action_reap(args): + reap_images() def main(): - global verbosity - database.connect() - - usage = """%prog [options] --add [--cdrom] cdrom_id description mirror_id uri_suffix - %prog [options] --add --mirror mirror_id uri_prefix - - %prog [options] --update [short_name1 [short_name2 ...]] - %prog [options] --reap""" - - parser = op.OptionParser(usage=usage) - parser.set_defaults(verbosity=0, - item='cdrom') - - parser.add_option('-a', '--add', action='store_const', - dest='action', const='add', - help='Add a new item to the database') - - parser.add_option('-u', '--update', action='store_const', - dest='action', const='update', - help='Update all cdrom images in the database with the latest version') - parser.add_option('-r', '--reap', action='store_const', - dest='action', const='reap', - help='Reap stale cdrom images that are no longer in use') - - a_group = op.OptionGroup(parser, 'Adding new items') - a_group.add_option('-c', '--cdrom', action='store_const', - dest='item', const='cdrom', - help='Add a new cdrom to the database') - a_group.add_option('-m', '--mirror', action='store_const', - dest='item', const='mirror', - help='Add a new mirror to the database') - parser.add_option_group(a_group) - - v_group = op.OptionGroup(parser, "Verbosity levels") - v_group.add_option("-q", "--quiet", action='store_const', - dest='verbosity', const=0, - help='Show no output from commands this script runs (default)') - v_group.add_option("-v", "--verbose", action='store_const', - dest='verbosity', const=1, - help='Show only errors from commands this script runs') - v_group.add_option("--noisy", action='store_const', - dest='verbosity', const=2, - help='Show all output from commands this script runs') - parser.add_option_group(v_group) - - (options, args) = parser.parse_args() - verbosity = options.verbosity - if options.action is None: - print parser.format_help() - elif options.action == 'add': - if options.item == 'cdrom': - attrs = dict(zip(('cdrom_id', 'description', 'mirror_id', 'uri_suffix'), - args)) - cdrom = database.CDROM(**attrs) - database.session.save(cdrom) - database.session.flush() - - load_image(cdrom) - - elif options.item == 'mirror': - attrs = dict(zip(('mirror_id', 'uri_prefix'), - args)) - mirror = database.Mirror(**attrs) - database.session.save(mirror) - database.session.flush() - elif options.action == 'update': - if len(args) > 0: - images = [database.CDROM.query().get(arg) for arg in args] - else: - images = database.CDROM.query().all() - for cdrom in images: - if cdrom is not None: - load_image(cdrom) - elif options.action == 'reap': - reap_images() + database.session.begin() + + parser = argparse.ArgumentParser(description='Perform actions on the CD-ROM images in the database') + subparsers = parser.add_subparsers(help='Action to perform') + + add_parser = subparsers.add_parser('add', help='Add new image to database') + add_parser.set_defaults(func=lambda args: add_parser.print_help()) + add_subparsers = add_parser.add_subparsers() + + add_cdrom_parser = add_subparsers.add_parser('cdrom') + add_cdrom_parser.add_argument('cdrom_id') + add_cdrom_parser.add_argument('description') + add_cdrom_parser.add_argument('mirror_id') + add_cdrom_parser.add_argument('uri_suffix') + add_cdrom_parser.set_defaults(func=action_add_cdrom) + + add_mirror_parser = add_subparsers.add_parser('mirror') + add_mirror_parser.add_argument('mirror_id') + add_mirror_parser.add_argument('uri_prefix') + add_mirror_parser.set_defaults(func=action_add_mirror) + + update_parser = subparsers.add_parser('update', help='Update images in database') + update_parser.add_argument('names', nargs='*', metavar='name', help='Shortnames of images to update') + update_parser.set_defaults(func=action_update) + + reap_parser = subparsers.add_parser('reap', help='Reap old images in database') + reap_parser.set_defaults(func=action_reap) + + args = parser.parse_args() + if 'func' in args: + args.func(args) + else: + parser.print_help() + if __name__ == '__main__': main()