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"""Update the lxc 'download' template cache for hosts on closed networks."""
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from __future__ import print_function
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from argparse import ArgumentParser
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from collections import namedtuple
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SITE = 'https://images.linuxcontainers.org'
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INDEX_PATH = 'meta/1.0'
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INDEX = 'index-system'
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ROOTFS = 'rootfs.tar.xz'
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LXC_CACHE = '/var/cache/lxc/download'
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'System', ['dist', 'release', 'arch', 'variant', 'version', 'path'])
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scp {rootfs_path} {meta_path} {user_host}:~/
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ssh {user_host} bash <<"EOT"
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sudo mkdir -p {lxc_cache}
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sudo mv ~/{rootfs} ~/{meta} {lxc_cache}
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sudo chown -R root:root {lxc_cache}
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sudo tar -C {lxc_cache} -xf {lxc_cache}/meta.tar.xz
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"""Manage the LXC download template cache."""
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def __init__(self, workspace, verbose=False, dry_run=False):
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"""Set the workspace for the local cache."""
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self.workspace = os.path.abspath(workspace)
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self.verbose = verbose
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self.dry_run = dry_run
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local_path = os.path.join(self.workspace, INDEX_PATH, INDEX)
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self.systems, ignore = self.init_systems(local_path)
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def init_systems(self, location):
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"""Return a tuple of the dict of lxc Systems and the source data.
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A System has these attributes: 'dist', 'release', 'arch', 'variant',
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'version', and 'path'. The dict keys are a tuple of
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(dist, release, arch, variant).
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if location.startswith('http'):
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request = urllib2.Request(location)
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response = urllib2.urlopen(request)
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data = response.read()
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with open(location) as f:
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if e.errno == errno.ENOENT:
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print('Local cache is empty.')
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for line in data.splitlines():
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system = System(*line.split(';'))
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key = (system.dist, system.release, system.arch, system.variant)
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def get_updates(self, dist, release, arch, variant):
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"""Return a tuple of the new system and the source data that match.
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The new system and source data will be None when there are
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no updates. The dist, release, arch, and variant args identify the
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key = (dist, release, arch, variant)
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old_system = self.systems.get(key)
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url = '%s/%s/%s' % (SITE, INDEX_PATH, INDEX)
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new_systems, data = self.init_systems(url)
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new_system = new_systems[key]
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if not old_system or new_system.version > old_system.version:
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print('Found new version for %s' % str(key))
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print(new_system.version)
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return new_system, data
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print('Version is current for %s' % str(key))
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print(old_system.version)
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def get_lxc_data(self, system):
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"""Download the system image and meta data.
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Return a tuple of the image and meta data paths.
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image_path = os.path.join(self.workspace, system.path[1:])
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print('creating %s' % image_path)
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if not os.path.isdir(image_path):
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os.makedirs(image_path)
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rootfs_path = os.path.join(image_path, ROOTFS)
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rootfs_url = '%s%s%s' % (SITE, system.path, ROOTFS)
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self.download(rootfs_url, rootfs_path)
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meta_path = os.path.join(image_path, META)
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meta_url = '%s%s%s' % (SITE, system.path, META)
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self.download(meta_url, meta_path)
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return rootfs_path, meta_path
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def download(self, location, path):
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"""Download a large binary from location to the specified path."""
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request = urllib2.Request(location)
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response = urllib2.urlopen(request)
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if response.getcode() == 200:
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with open(path, 'wb') as f:
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shutil.copyfileobj(response, f, chunk)
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print('Downloaded %s' % location)
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def put_lxc_data(self, user_host, system, rootfs_path, meta_path):
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"""Install the lxc image and meta data on the host.
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The user on the host must have password-less sudo.
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lxc_cache = os.path.join(
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LXC_CACHE, system.dist, system.release, system.arch,
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put_script = PUT_SCRIPT.format(
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user_host=user_host, rootfs_path=rootfs_path, meta_path=meta_path)
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subprocess.check_call([put_script], shell=True)
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print("Uploaded %s and %s" % (ROOTFS, META))
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install_script = INSTALL_SCRIPT.format(
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user_host=user_host, lxc_cache=lxc_cache, rootfs=ROOTFS, meta=META)
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subprocess.check_call([install_script], shell=True)
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print("Installed %s and %s" % (ROOTFS, META))
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def save_index(self, data):
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"Save the (current) index data for future calls to get_updates()."
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index_dir = os.path.join(self.workspace, INDEX_PATH)
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if not os.path.isdir(index_dir):
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os.makedirs(index_dir)
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index_path = os.path.join(self.workspace, INDEX_PATH, INDEX)
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with open(index_path, 'w') as f:
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print('saved index: %s' % INDEX)
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def parse_args(argv=None):
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"""Return the argument parser for this program."""
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parser = ArgumentParser(
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"Update a remote host's download lxc template cache.")
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'-d', '--dry-run', action='store_true', default=False,
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help='Do not make changes.')
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'-v', '--verbose', action='store_true', default=False,
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help='Increase verbosity.')
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'--dist', default="ubuntu", help="The distribution to update.")
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'--variant', default="default", help="The variant to update.")
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'user_host', help='The user@host to update.')
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'release', help='The release to update.')
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'arch', help='The architecture of the remote host')
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'workspace', help='The path to the local dir to stage the update.')
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args = parser.parse_args(argv)
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"""Update the lxc download template cache for hosts on closed networks."""
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args = parse_args(argv)
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lxc_cache = LxcCache(
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args.workspace, verbose=args.verbose, dry_run=args.dry_run)
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new_system, data = lxc_cache.get_updates(
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args.dist, args.release, args.arch, args.variant)
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rootfs_path, meta_path = lxc_cache.get_lxc_data(new_system)
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lxc_cache.put_lxc_data(
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args.user_host, new_system, rootfs_path, meta_path)
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lxc_cache.save_index(data)
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except Exception as e:
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print(getattr(e, 'output', ''))
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traceback.print_tb(sys.exc_info()[2])
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if __name__ == '__main__':
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sys.exit(main(sys.argv[1:]))
added
removed
update_lxc_cache.py
