Source code for pylorax.api.yumbase

#
# Copyright (C) 2017  Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# pylint: disable=bad-preconf-access

import logging
log = logging.getLogger("lorax-composer")

import ConfigParser
from fnmatch import fnmatchcase
from glob import glob
import os
from threading import Lock
import time
import yum
from yum.Errors import YumBaseError

# This is a hack to short circuit yum's internal logging
yum.logginglevels._added_handlers = True

from pylorax.sysutils import joinpaths

[docs]class YumLock(object): """Hold the YumBase object and a Lock to control access to it. self.yb is a property that returns the YumBase object, but it *may* change from one call to the next if the upstream repositories have changed. """ def __init__(self, conf, expire_secs=6*60*60): self._conf = conf self._lock = Lock() self.yb = get_base_object(self._conf) self._expire_secs = expire_secs self._expire_time = time.time() + self._expire_secs @property
[docs] def lock(self): """Check for repo updates (using expiration time) and return the lock If the repository has been updated, tear down the old YumBase and create a new one. This is the only way to force yum to use the new metadata. """ if time.time() > self._expire_time: return self.lock_check return self._lock
@property
[docs] def lock_check(self): """Force a check for repo updates and return the lock If the repository has been updated, tear down the old YumBase and create a new one. This is the only way to force yum to use the new metadata. Use this method sparingly, it removes the repodata and downloads a new copy every time. """ self._expire_time = time.time() + self._expire_secs if self._haveReposChanged(): self._destroyYb() self.yb = get_base_object(self._conf) return self._lock
def _destroyYb(self): # Do our best to get yum to let go of all the things... self.yb.pkgSack.dropCachedData() for s in self.yb.pkgSack.sacks.values(): s.close() del s del self.yb.pkgSack self.yb.closeRpmDB() del self.yb.tsInfo del self.yb.ts self.yb.close() del self.yb def _haveReposChanged(self): """Return True if the repo has new metadata""" # This is a total kludge, yum doesn't really expect to deal with things changing while the # object is is use. try: before = [(r.id, r.repoXML.checksums["sha256"]) for r in sorted(self.yb.repos.listEnabled())] for r in sorted(self.yb.repos.listEnabled()): r.metadata_expire = 0 del r.repoXML after = [(r.id, r.repoXML.checksums["sha256"]) for r in sorted(self.yb.repos.listEnabled())] return before != after except Exception: return False
[docs]def get_base_object(conf): """Get the Yum object with settings from the config file :param conf: configuration object :type conf: ComposerParser :returns: A Yum base object :rtype: YumBase """ cachedir = os.path.abspath(conf.get("composer", "cache_dir")) yumconf = os.path.abspath(conf.get("composer", "yum_conf")) yumroot = os.path.abspath(conf.get("composer", "yum_root")) repodir = os.path.abspath(conf.get("composer", "repo_dir")) c = ConfigParser.ConfigParser() # add the main section section = "main" data = {"cachedir": cachedir, "keepcache": 0, "gpgcheck": 0, "plugins": 0, "assumeyes": 1, "reposdir": "", "tsflags": "nodocs"} if conf.get_default("yum", "proxy", None): data["proxy"] = conf.get("yum", "proxy") if conf.has_option("yum", "sslverify") and not conf.getboolean("yum", "sslverify"): data["sslverify"] = "0" c.add_section(section) map(lambda (key, value): c.set(section, key, value), data.items()) # write the yum configuration file with open(yumconf, "w") as f: c.write(f) # create the yum base object yb = yum.YumBase() yb.preconf.fn = yumconf yb.preconf.root = yumroot if not os.path.isdir(yb.preconf.root): os.makedirs(yb.preconf.root) _releasever = conf.get_default("composer", "releasever", None) if not _releasever: distroverpkg = ['system-release(releasever)', 'redhat-release'] # Use yum private function to guess the releasever _releasever = yum.config._getsysver("/", distroverpkg) log.info("releasever = %s", _releasever) yb.preconf.releasever = _releasever # Turn on as much yum logging as we can yb.preconf.debuglevel = 6 yb.preconf.errorlevel = 6 yb.logger.setLevel(logging.DEBUG) yb.verbose_logger.setLevel(logging.DEBUG) # Gather up all the available repo files, add the ones matching "repos":"enabled" patterns enabled_repos = conf.get("repos", "enabled").split(",") repo_files = glob(joinpaths(repodir, "*.repo")) if not conf.has_option("repos", "use_system_repos") or conf.getboolean("repos", "use_system_repos"): repo_files.extend(glob("/etc/yum.repos.d/*.repo")) for repo_file in repo_files: name = os.path.basename(repo_file)[:-5] if any(map(lambda pattern: fnmatchcase(name, pattern), enabled_repos)): # pylint: disable=cell-var-from-loop yb.getReposFromConfigFile(repo_file) # Remove any duplicate repo entries. These can cause problems with Anaconda, which will fail # with space problems. repos = list(r.id for r in yb.repos.listEnabled()) seen = {"baseurl": [], "mirrorlist": [], "metalink": []} for source_name in repos: remove = False repo = yb.repos.getRepo(source_name) if repo.baseurl: if repo.baseurl[0] in seen["baseurl"]: log.info("Removing duplicate repo: %s baseurl=%s", source_name, repo.baseurl[0]) remove = True else: seen["baseurl"].append(repo.baseurl[0]) elif repo.mirrorlist: if repo.mirrorlist in seen["mirrorlist"]: log.info("Removing duplicate repo: %s mirrorlist=%s", source_name, repo.mirrorlist) remove = True else: seen["mirrorlist"].append(repo.mirrorlist) if remove: yb.repos.delete(source_name) # delete doesn't remove it from the cache used by listEnabled so we have to force it yb.repos._cache_enabled_repos = None # Update the metadata from the enabled repos to speed up later operations log.info("Updating yum repository metadata") update_metadata(yb) return yb
[docs]def update_metadata(yb): """Update the metadata for all the enabled repos :param yb: The Yum base object :type yb: yum.YumBase :returns: None :rtype: None """ for r in yb.repos.sort(): r.metadata_expire = 0 r.mdpolicy = "group:all" try: yb.doRepoSetup() yb.repos.doSetup() yb.repos.populateSack(mdtype='all', cacheonly=0) except YumBaseError as e: log.error("Failed to update metadata: %s", str(e)) raise RuntimeError("Fetching metadata failed: %s" % str(e))