diff options
Diffstat (limited to 'src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py')
| -rw-r--r-- | src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py b/src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py new file mode 100644 index 000000000..32db0b32d --- /dev/null +++ b/src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py @@ -0,0 +1,384 @@ +""" Libraries for bcfg2-yum-helper plugin, used if yum library support +is enabled. The yum libs have horrific memory leaks, so apparently +the right way to get around that in long-running processes it to have +a short-lived helper. No, seriously -- check out the yum-updatesd +code. It's pure madness. """ + +import os +import sys +import yum +import logging +import Bcfg2.Options +import Bcfg2.Logger +from Bcfg2.Compat import wraps +from lockfile import FileLock, LockTimeout +try: + import json +except ImportError: + import simplejson as json + + +def pkg_to_tuple(package): + """ json doesn't distinguish between tuples and lists, but yum + does, so we convert a package in list format to one in tuple + format """ + if isinstance(package, list): + return tuple(package) + else: + return package + + +def pkgtup_to_string(package): + """ given a package tuple, return a human-readable string + describing the package """ + if package[3] in ['auto', 'any']: + return package[0] + + rv = [package[0], "-"] + if package[2]: + rv.extend([package[2], ':']) + rv.extend([package[3], '-', package[4]]) + if package[1]: + rv.extend(['.', package[1]]) + return ''.join(str(e) for e in rv) + + +class YumHelper(object): + """ Yum helper base object """ + + def __init__(self, cfgfile, verbose=1): + self.cfgfile = cfgfile + self.yumbase = yum.YumBase() + # pylint: disable=E1121,W0212 + try: + self.yumbase.preconf.debuglevel = verbose + self.yumbase.preconf.fn = cfgfile + self.yumbase._getConfig() + except AttributeError: + self.yumbase._getConfig(cfgfile, debuglevel=verbose) + # pylint: enable=E1121,W0212 + self.logger = logging.getLogger(self.__class__.__name__) + + +class DepSolver(YumHelper): + """ Yum dependency solver. This is used for operations that only + read from the yum cache, and thus operates in cacheonly mode. """ + + def __init__(self, cfgfile, verbose=1): + YumHelper.__init__(self, cfgfile, verbose=verbose) + # internally, yum uses an integer, not a boolean, for conf.cache + self.yumbase.conf.cache = 1 + self._groups = None + + def get_groups(self): + """ getter for the groups property """ + if self._groups is not None: + return self._groups + else: + return ["noarch"] + + def set_groups(self, groups): + """ setter for the groups property """ + self._groups = set(groups).union(["noarch"]) + + groups = property(get_groups, set_groups) + + def get_package_object(self, pkgtup, silent=False): + """ given a package tuple, get a yum package object """ + try: + matches = yum.packageSack.packagesNewestByName( + self.yumbase.pkgSack.searchPkgTuple(pkgtup)) + except yum.Errors.PackageSackError: + if not silent: + self.logger.warning("Package '%s' not found" % + self.get_package_name(pkgtup)) + matches = [] + except yum.Errors.RepoError: + err = sys.exc_info()[1] + self.logger.error("Temporary failure loading metadata for %s: %s" % + (self.get_package_name(pkgtup), err)) + matches = [] + + pkgs = self._filter_arch(matches) + if pkgs: + return pkgs[0] + else: + return None + + def get_group(self, group, ptype="default"): + """ Resolve a package group name into a list of packages """ + if group.startswith("@"): + group = group[1:] + + try: + if self.yumbase.comps.has_group(group): + group = self.yumbase.comps.return_group(group) + else: + self.logger.error("%s is not a valid group" % group) + return [] + except yum.Errors.GroupsError: + err = sys.exc_info()[1] + self.logger.warning(err) + return [] + + if ptype == "default": + return [p + for p, d in list(group.default_packages.items()) + if d] + elif ptype == "mandatory": + return [p + for p, m in list(group.mandatory_packages.items()) + if m] + elif ptype == "optional" or ptype == "all": + return group.packages + else: + self.logger.warning("Unknown group package type '%s'" % ptype) + return [] + + def _filter_arch(self, packages): + """ filter packages in the given list that do not have an + architecture in the list of groups for this client """ + matching = [] + for pkg in packages: + if pkg.arch in self.groups: + matching.append(pkg) + else: + self.logger.debug("%s has non-matching architecture (%s)" % + (pkg, pkg.arch)) + if matching: + return matching + else: + # no packages match architecture; we'll assume that the + # user knows what s/he is doing and this is a multiarch + # box. + return packages + + def get_package_name(self, package): + """ get the name of a package or virtual package from the + internal representation used by this Collection class """ + if isinstance(package, tuple): + if len(package) == 3: + return yum.misc.prco_tuple_to_string(package) + else: + return pkgtup_to_string(package) + else: + return str(package) + + def complete(self, packagelist): + """ resolve dependencies and generate a complete package list + from the given list of initial packages """ + packages = set() + unknown = set() + for pkg in packagelist: + if isinstance(pkg, tuple): + pkgtup = pkg + else: + pkgtup = (pkg, None, None, None, None) + pkgobj = self.get_package_object(pkgtup) + if not pkgobj: + self.logger.debug("Unknown package %s" % + self.get_package_name(pkg)) + unknown.add(pkg) + else: + if self.yumbase.tsInfo.exists(pkgtup=pkgobj.pkgtup): + self.logger.debug("%s added to transaction multiple times" + % pkgobj) + else: + self.logger.debug("Adding %s to transaction" % pkgobj) + self.yumbase.tsInfo.addInstall(pkgobj) + self.yumbase.resolveDeps() + + for txmbr in self.yumbase.tsInfo: + packages.add(txmbr.pkgtup) + return list(packages), list(unknown) + + +def acquire_lock(func): + """ decorator for CacheManager methods that gets and release a + lock while the method runs """ + @wraps(func) + def inner(self, *args, **kwargs): + """ Get and release a lock while running the function this + wraps. """ + self.logger.debug("Acquiring lock at %s" % self.lockfile) + while not self.lock.i_am_locking(): + try: + self.lock.acquire(timeout=60) # wait up to 60 seconds + except LockTimeout: + self.lock.break_lock() + self.lock.acquire() + try: + func(self, *args, **kwargs) + finally: + self.lock.release() + self.logger.debug("Released lock at %s" % self.lockfile) + + return inner + + +class CacheManager(YumHelper): + """ Yum cache manager. Unlike :class:`DepSolver`, this can write + to the yum cache, and so is used for operations that muck with the + cache. (Technically, :func:`CacheManager.clean_cache` could be in + either DepSolver or CacheManager, but for consistency I've put it + here.) """ + + def __init__(self, cfgfile, verbose=1): + YumHelper.__init__(self, cfgfile, verbose=verbose) + self.lockfile = \ + os.path.join(os.path.dirname(self.yumbase.conf.config_file_path), + "lock") + self.lock = FileLock(self.lockfile) + + @acquire_lock + def clean_cache(self): + """ clean the yum cache """ + for mdtype in ["Headers", "Packages", "Sqlite", "Metadata", + "ExpireCache"]: + # for reasons that are entirely obvious, all of the yum + # API clean* methods return a tuple of 0 (zero, always + # zero) and a list containing a single message about how + # many files were deleted. so useful. thanks, yum. + msg = getattr(self.yumbase, "clean%s" % mdtype)()[1][0] + if not msg.startswith("0 "): + self.logger.info(msg) + + @acquire_lock + def populate_cache(self): + """ populate the yum cache """ + for repo in self.yumbase.repos.findRepos('*'): + repo.metadata_expire = 0 + repo.mdpolicy = "group:all" + self.yumbase.doRepoSetup() + self.yumbase.repos.doSetup() + for repo in self.yumbase.repos.listEnabled(): + # this populates the cache as a side effect + repo.repoXML # pylint: disable=W0104 + try: + repo.getGroups() + except yum.Errors.RepoMDError: + pass # this repo has no groups + self.yumbase.repos.populateSack(mdtype='metadata', cacheonly=1) + self.yumbase.repos.populateSack(mdtype='filelists', cacheonly=1) + self.yumbase.repos.populateSack(mdtype='otherdata', cacheonly=1) + # this does something with the groups cache as a side effect + self.yumbase.comps # pylint: disable=W0104 + + +class HelperSubcommand(Bcfg2.Options.Subcommand): + # the value to JSON encode and print out if the command fails + fallback = None + + # whether or not this command accepts input on stdin + accept_input = True + + def __init__(self): + Bcfg2.Options.Subcommand.__init__(self) + self.verbosity = 0 + if Bcfg2.Options.setup.debug: + self.verbosity = 5 + elif Bcfg2.Options.setup.verbose: + self.verbosity = 1 + + def run(self, setup): + try: + data = json.loads(sys.stdin.read()) + except: # pylint: disable=W0702 + self.logger.error("Unexpected error decoding JSON input: %s" % + sys.exc_info()[1]) + print(json.dumps(self.fallback)) + return 2 + + try: + print(json.dumps(self._run(setup, data))) + except: # pylint: disable=W0702 + self.logger.error("Unexpected error running %s: %s" % + self.__class__.__name__.lower(), + sys.exc_info()[1], exc_info=1) + print(json.dumps(self.fallback)) + return 2 + return 0 + + def _run(self, setup, data): + raise NotImplementedError + + +class DepSolverSubcommand(HelperSubcommand): + def __init__(self): + HelperSubcommand.__init__(self) + self.depsolver = DepSolver(Bcfg2.Options.setup.yum_config, + self.verbosity) + + +class CacheManagerSubcommand(HelperSubcommand): + fallback = False + accept_input = False + + def __init__(self): + HelperSubcommand.__init__(self) + self.cachemgr = CacheManager(Bcfg2.Options.setup.yum_config, + self.verbosity) + + +class Clean(CacheManagerSubcommand): + def _run(self, setup, data): # pylint: disable=W0613 + self.cachemgr.clean_cache() + return True + + +class MakeCache(CacheManagerSubcommand): + def _run(self, setup, data): # pylint: disable=W0613 + self.cachemgr.populate_cache() + return True + + +class Complete(DepSolverSubcommand): + fallback = dict(packages=[], unknown=[]) + + def _run(self, _, data): + self.depsolver.groups = data['groups'] + self.fallback['unknown'] = data['packages'] + (packages, unknown) = self.depsolver.complete( + [pkg_to_tuple(p) for p in data['packages']]) + return dict(packages=list(packages), unknown=list(unknown)) + + +class GetGroups(DepSolverSubcommand): + def _run(self, _, data): + rv = dict() + for gdata in data: + if "type" in gdata: + packages = self.depsolver.get_group(gdata['group'], + ptype=gdata['type']) + else: + packages = self.depsolver.get_group(gdata['group']) + rv[gdata['group']] = list(packages) + return rv + + +Get_Groups = GetGroups + + +class CLI(Bcfg2.Options.CommandRegistry): + options = [ + Bcfg2.Options.PathOption( + "-c", "--yum-config", help="Yum config file"), + Bcfg2.Options.PositionalArgument( + "command", help="Yum helper command", + choices=['clean', 'complete', 'get_groups'])] + + def __init__(self): + Bcfg2.Options.CommandRegistry.__init__(self) + Bcfg2.Options.register_commands(self.__class__, globals().values(), + parent=HelperSubcommand) + parser = Bcfg2.Options.get_parser("Bcfg2 yum helper", + components=[self]) + parser.parse() + self.logger = logging.getLogger(parser.prog) + + def run(self): + if not os.path.exists(Bcfg2.Options.setup.yum_config): + self.logger.error("Config file %s not found" % + Bcfg2.Options.setup.yum_config) + return 1 + return self.runcommand() |