Use #!/usr/bin/env python3 shebang
Remove verbosity argument and just use exceptions to display error conditions
Use subprocess.run instead of Popen to throw exceptions upon command failure
Use modern string formatting instead of %
Clean up formatting according to what pylint recommends
+invirt-images (0.0.7) precise; urgency=medium
+
+ * Port to Python 3
+
+ -- Ben Steffen <bds@mit.edu> Sun, 24 Nov 2019 22:03:30 -0500
+
invirt-images (0.0.6) precise; urgency=low
* Fixing images for new lv setup to deactivate volumes before modifying.
invirt-images (0.0.6) precise; urgency=low
* Fixing images for new lv setup to deactivate volumes before modifying.
Maintainer: Invirt project <invirt@mit.edu>
Build-Depends: debhelper (>= 7)
Standards-Version: 3.9.3
Maintainer: Invirt project <invirt@mit.edu>
Build-Depends: debhelper (>= 7)
Standards-Version: 3.9.3
+X-Python3-Version: >= 3.6
Package: invirt-images
Architecture: all
Package: invirt-images
Architecture: all
-Depends: ${shlibs:Depends}, ${misc:Depends}, python, invirt-database
+Depends: ${shlibs:Depends}, ${misc:Depends}, ${python3:Depends}, invirt-database
Description: Invirt's tools for managing disk images for VMs
These install the tools for managing disk images for Invirt
VMs. Images can share common mirrors. The tools include mechanisms
Description: Invirt's tools for managing disk images for VMs
These install the tools for managing disk images for Invirt
VMs. Images can share common mirrors. The tools include mechanisms
-#!/usr/bin/python
-
-from __future__ import print_function
-from future import standard_library
-standard_library.install_aliases()
-from builtins import map
-from builtins import zip
-from builtins import range
-from invirt import database
+#!/usr/bin/env python3
+
import subprocess
import random
import string
import tempfile
import subprocess
import random
import string
import tempfile
-import urllib.request, urllib.parse, urllib.error
-import optparse as op
-
-class InvirtImageException(Exception):
- pass
-# 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):
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)
- lvr = subprocess.Popen(['lvchange', '-an', "xenvg/%s" % (src,)],
- stderr=subprocess.PIPE,
- stdout=getOutput()['stdout'])
- ret = lvr.wait()
-
- if ret:
- if verbosity > 0:
- print(lvr.stderr.read())
- return ret
-
- lvr = subprocess.Popen(['lvrename', "xenvg/%s" % (src,), "xenvg/%s" % (dest,)],
- stderr=subprocess.PIPE,
- stdout=getOutput()['stdout'])
- ret = lvr.wait()
+ subprocess.run(['lvchange', '-an', f'xenvg/{src}'],
+ check_output=True, encoding='utf-8', check=True)
- if ret:
- stderr = lvr.stderr.read()
- if not ('not found in volume group' in stderr):
- if verbosity > 0:
- print(stderr)
- return ret
-
- subprocess.Popen(['lvchange', '-ay', "xenvg/%s" % (dest,)],
- stderr=subprocess.PIPE,
- stdout=getOutput()['stdout'])
- ret = lvr.wait()
-
- if ret:
- if verbosity > 0:
- print(lvr.stderr.read())
-
- return ret
+ 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):
"""
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
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:
# Keep trying until it works
while True:
- rand_string = ''.join(random.choice(string.ascii_letters) \
- for i in range(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
"""
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]
full_uri = os.path.join(cdrom.mirror.uri_prefix, cdrom.uri_suffix)
temp_file = tempfile.mkstemp()[1]
- if verbosity > 0:
- print("Fetching image %s from %s to %s" % (cdrom.cdrom_id, full_uri, temp_file), file=sys.stderr)
+ print(f'Fetching image {cdrom.cdrom_id} from {full_uri} to {temp_file}')
try:
if full_uri.startswith('rsync://'):
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.request.urlretrieve(full_uri, temp_file)
return temp_file
except:
else:
# I'm not going to look for errors here, because I bet it'll
# throw its own exceptions
urllib.request.urlretrieve(full_uri, temp_file)
return temp_file
except:
raise
def copy_file(src, dest):
"""
Copy a file from one location to another using dd
"""
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):
"""
def load_image(cdrom):
"""
transferring it into an LV, moving the old LV out of the way and
the new LV into place
"""
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
if cdrom.mirror_id is None:
return
- try:
- temp_file = fetch_image(cdrom)
- except InvirtImageException as e:
- print('ERROR: %s. Skipping.' % e, file=sys.stderr)
- 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'
- st_size = os.stat(temp_file).st_size
- if not st_size:
- print("Failed to fetch %s" % cdrom.cdrom_id, file=sys.stderr)
- 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)
def reap_images():
"""
Remove stale cdrom images that are no longer in use
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.
"""
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_'):
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}'])
database.connect()
database.session.begin()
database.connect()
database.session.begin()
%prog [options] --update [short_name1 [short_name2 ...]]
%prog [options] --reap"""
%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.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('-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')
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')
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)
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)')
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)
dest='verbosity', const=2,
help='Show all output from commands this script runs')
parser.add_option_group(v_group)
(options, args) = parser.parse_args()
(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(list(zip(('cdrom_id', 'description', 'mirror_id', 'uri_suffix'),
if options.action is None:
print(parser.format_help())
elif options.action == 'add':
if options.item == 'cdrom':
attrs = dict(list(zip(('cdrom_id', 'description', 'mirror_id', 'uri_suffix'),
cdrom = database.CDROM(**attrs)
database.session.add(cdrom)
database.session.commit()
cdrom = database.CDROM(**attrs)
database.session.add(cdrom)
database.session.commit()
elif options.item == 'mirror':
attrs = dict(list(zip(('mirror_id', 'uri_prefix'),
elif options.item == 'mirror':
attrs = dict(list(zip(('mirror_id', 'uri_prefix'),
mirror = database.Mirror(**attrs)
database.session.add(mirror)
database.session.commit()
mirror = database.Mirror(**attrs)
database.session.add(mirror)
database.session.commit()