-#!/usr/bin/python
+#!/usr/bin/env python3
-from invirt import database
import os
-import sys
import subprocess
import random
import string
import tempfile
-import urllib
+import urllib.request
import math
-import optparse as op
-
-class InvirtImageException(Exception):
- pass
+import optparse
-# 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]
- if verbosity > 0:
- print >>sys.stderr, "Fetching image %s from %s to %s" % (cdrom.cdrom_id, full_uri, temp_file)
+ 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):
"""
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
- try:
- temp_file = fetch_image(cdrom)
- except InvirtImageException, e:
- print >>sys.stderr, 'ERROR: %s. Skipping.' % e
- 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:
- st_size = os.stat(temp_file).st_size
- if not st_size:
- print >>sys.stderr, "Failed to fetch %s" % cdrom.cdrom_id
- return
- cdrom_size = '%sM' % math.ceil((float(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 main():
- global verbosity
-
database.connect()
database.session.begin()
%prog [options] --update [short_name1 [short_name2 ...]]
%prog [options] --reap"""
-
- parser = op.OptionParser(usage=usage)
+
+ parser = optparse.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 = optparse.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')
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 = optparse.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)')
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()
+ print(parser.format_help())
elif options.action == 'add':
if options.item == 'cdrom':
- attrs = dict(zip(('cdrom_id', 'description', 'mirror_id', 'uri_suffix'),
- args))
+ attrs = dict(list(zip(('cdrom_id', 'description', 'mirror_id', 'uri_suffix'),
+ args)))
cdrom = database.CDROM(**attrs)
database.session.add(cdrom)
database.session.commit()
-
+
load_image(cdrom)
-
+
elif options.item == 'mirror':
- attrs = dict(zip(('mirror_id', 'uri_prefix'),
- args))
+ attrs = dict(list(zip(('mirror_id', 'uri_prefix'),
+ args)))
mirror = database.Mirror(**attrs)
database.session.add(mirror)
database.session.commit()