""" This module allows you to probe a client for a file, which is then added to the specification. On subsequent runs, the file will be replaced on the client if it is missing; if it has changed on the client, it can either be updated in the specification or replaced on the client """ import os import errno import binascii import lxml.etree import Bcfg2.Options import Bcfg2.Server.Plugin probecode = """#!/usr/bin/env python import os import pwd import grp import binascii import lxml.etree path = "%s" if not os.path.exists(path): print "%%s does not exist" %% path raise SystemExit(1) stat = os.stat(path) data = lxml.etree.Element("ProbedFileData", name=path, owner=pwd.getpwuid(stat[4])[0], group=grp.getgrgid(stat[5])[0], perms=oct(stat[0] & 07777)) data.text = binascii.b2a_base64(open(path).read()) print lxml.etree.tostring(data) """ class FileProbesConfig(Bcfg2.Server.Plugin.SingleXMLFileBacked, Bcfg2.Server.Plugin.StructFile): """ Config file handler for FileProbes """ def __init__(self, filename, fam): Bcfg2.Server.Plugin.SingleXMLFileBacked.__init__(self, filename, fam) Bcfg2.Server.Plugin.StructFile.__init__(self, filename) class FileProbes(Bcfg2.Server.Plugin.Plugin, Bcfg2.Server.Plugin.Probing): """ This module allows you to probe a client for a file, which is then added to the specification. On subsequent runs, the file will be replaced on the client if it is missing; if it has changed on the client, it can either be updated in the specification or replaced on the client """ name = 'FileProbes' experimental = True __author__ = 'chris.a.st.pierre@gmail.com' def __init__(self, core, datastore): Bcfg2.Server.Plugin.Plugin.__init__(self, core, datastore) Bcfg2.Server.Plugin.Probing.__init__(self) self.config = FileProbesConfig(os.path.join(self.data, 'config.xml'), core.fam) self.entries = dict() self.probes = dict() def GetProbes(self, metadata): """Return a set of probes for execution on client.""" if metadata.hostname not in self.probes: cfg = self.core.plugins['Cfg'] self.entries[metadata.hostname] = dict() self.probes[metadata.hostname] = [] for entry in self.config.Match(metadata): path = entry.get("name") # do not probe for files that are already in Cfg and # for which update is false; we can't possibly do # anything with the data we get from such a probe try: if (entry.get('update', 'false').lower() == "false" and cfg.entries[path].get_pertinent_entries(entry, metadata)): continue except (KeyError, Bcfg2.Server.Plugin.PluginExecutionError): pass self.entries[metadata.hostname][path] = entry probe = lxml.etree.Element('probe', name=path, source=self.name, interpreter="/usr/bin/env python") probe.text = probecode % path self.probes[metadata.hostname].append(probe) self.logger.debug("Adding file probe for %s to %s" % (path, metadata.hostname)) return self.probes[metadata.hostname] def ReceiveData(self, metadata, datalist): """Receive data from probe.""" self.logger.debug("Receiving file probe data from %s" % metadata.hostname) for data in datalist: if data.text is None: self.logger.error("Got null response to %s file probe from %s" % (data.get('name'), metadata.hostname)) else: self.logger.debug("%s:fileprobe:%s:%s" % (metadata.hostname, data.get("name"), data.text)) try: filedata = lxml.etree.XML(data.text) self.write_file(filedata, metadata) except lxml.etree.XMLSyntaxError: # if we didn't get XML back from the probe, assume # it's an error message self.logger.error(data.text) def write_file(self, data, metadata): """Write the probed file data to the bcfg2 specification.""" filename = data.get("name") contents = binascii.a2b_base64(data.text) entry = self.entries[metadata.hostname][filename] cfg = self.core.plugins['Cfg'] specific = "%s.H_%s" % (os.path.basename(filename), metadata.hostname) # we can't use os.path.join() for this because specific # already has a leading /, which confuses os.path.join() fileloc = "%s%s" % (cfg.data, os.path.join(filename, specific)) create = False try: cfg.entries[filename].bind_entry(entry, metadata) except Bcfg2.Server.Plugin.PluginExecutionError: create = True # get current entry data if entry.text and entry.get("encoding") == "base64": entrydata = binascii.a2b_base64(entry.text) else: entrydata = entry.text if create: self.logger.info("Writing new probed file %s" % fileloc) try: os.makedirs(os.path.dirname(fileloc)) except OSError, err: if err.errno == errno.EEXIST: pass else: raise open(fileloc, 'wb').write(contents) infoxml = os.path.join("%s%s" % (cfg.data, filename), "info.xml") if not os.path.exists(infoxml): self.write_infoxml(infoxml, entry, data) # Service the FAM events queued up by the key generation # so the data structure entries will be available for # binding. # # NOTE: We wait for up to ten seconds. There is some # potential for race condition, because if the file # monitor doesn't get notified about the new key files in # time, those entries won't be available for binding. In # practice, this seems "good enough". tries = 0 is_bound = False while not is_bound: if tries >= 10: self.logger.error("%s still not registered" % filename) raise Bcfg2.Server.Plugin.PluginExecutionError self.core.fam.handle_events_in_interval(1) try: cfg.entries[filename].bind_entry(entry, metadata) is_bound = True except Bcfg2.Server.Plugin.PluginExecutionError: pass tries += 1 elif entrydata == contents: self.logger.debug("Existing %s contents match probed contents" % filename) return elif (entry.get('update', 'false').lower() == "true"): self.logger.info("Writing updated probed file %s" % fileloc) open(fileloc, 'wb').write(contents) # service FAM events tries = 0 updated = False while not updated: if tries >= 10: self.logger.error("%s still not registered" % filename) raise Bcfg2.Server.Plugin.PluginExecutionError self.core.fam.handle_events_in_interval(1) cfg.entries[filename].bind_entry(entry, metadata) # get current entry data if entry.get("encoding") == "base64": entrydata = binascii.a2b_base64(entry.text) else: entrydata = entry.text if entrydata == contents: updated = True tries += 1 else: self.logger.info("Skipping updated probed file %s" % fileloc) return def write_infoxml(self, infoxml, entry, data): """ write an info.xml for the file """ self.logger.info("Writing info.xml at %s for %s" % (infoxml, data.get("name"))) info = \ lxml.etree.Element("Info", owner=data.get("owner", Bcfg2.Options.MDATA_OWNER.value), group=data.get("group", Bcfg2.Options.MDATA_GROUP.value), perms=data.get("perms", Bcfg2.Options.MDATA_PERMS.value), encoding=entry.get("encoding", Bcfg2.Options.ENCODING.value)) root = lxml.etree.Element("FileInfo") root.append(info) open(infoxml, "w").write(lxml.etree.tostring(root, pretty_print=True))