""" 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 sys import errno import lxml.etree import Bcfg2.Server import Bcfg2.Server.Plugin import Bcfg2.Server.FileMonitor from Bcfg2.Compat import b64decode #: The probe we send to clients to get the file data. Returns an XML #: document describing the file and its metadata. We avoid returning #: a non-0 error code on most errors, since that could halt client #: execution. PROBECODE = """#!/usr/bin/env python import os import sys import pwd import grp import Bcfg2.Client.XML try: from Bcfg2.Compat import b64encode, oct_mode except ImportError: from base64 import b64encode oct_mode = oct path = "%s" if not os.path.exists(path): sys.stderr.write("%%s does not exist" %% path) raise SystemExit(0) try: stat = os.stat(path) except OSError: sys.stderr.write("Could not stat %%s: %%s" %% (path, sys.exc_info()[1])) raise SystemExit(0) data = Bcfg2.Client.XML.Element("ProbedFileData", name=path, owner=pwd.getpwuid(stat[4])[0], group=grp.getgrgid(stat[5])[0], mode=oct_mode(stat[0] & 4095)) try: data.text = b64encode(open(path).read()) except IOError: sys.stderr.write("Could not read %%s: %%s" %% (path, sys.exc_info()[1])) raise SystemExit(0) print(Bcfg2.Client.XML.tostring(data, xml_declaration=False).decode('UTF-8')) """ 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 """ __author__ = 'chris.a.st.pierre@gmail.com' def __init__(self, core): Bcfg2.Server.Plugin.Plugin.__init__(self, core) Bcfg2.Server.Plugin.Probing.__init__(self) self.config = \ Bcfg2.Server.Plugin.StructFile(os.path.join(self.data, 'config.xml'), should_monitor=True, create=self.name) 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 if (entry.get('update', 'false').lower() == "false" and not cfg.has_generator(entry, metadata)): continue 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.debug_log("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.debug_log("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: try: self.write_data( lxml.etree.XML(data.text, parser=Bcfg2.Server.XMLParser), 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_data(self, data, metadata): """Write the probed file data to the bcfg2 specification.""" filename = data.get("name") contents = b64decode(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 = os.path.join(cfg.data, os.path.join(filename, specific).lstrip("/")) create = False try: cfg.entries[filename].bind_entry(entry, metadata) except (KeyError, Bcfg2.Server.Plugin.PluginExecutionError): create = True # get current entry data if entry.text and entry.get("encoding") == "base64": entrydata = b64decode(entry.text) else: entrydata = entry.text if create: self.logger.info("Writing new probed file %s" % fileloc) self.write_file(fileloc, contents) self.verify_file(filename, contents, metadata) infoxml = os.path.join(cfg.data, filename.lstrip("/"), "info.xml") self.write_infoxml(infoxml, data) elif entrydata == contents: self.debug_log("Existing %s contents match probed contents" % filename) return elif (entry.get('update', 'false').lower() == "true"): self.logger.info("Writing updated probed file %s" % fileloc) self.write_file(fileloc, contents) self.verify_file(filename, contents, metadata) else: self.logger.info("Skipping updated probed file %s" % fileloc) return def write_file(self, fileloc, contents): """ Write the probed file to disk """ try: os.makedirs(os.path.dirname(fileloc)) except OSError: err = sys.exc_info()[1] if err.errno == errno.EEXIST: pass else: self.logger.error("Could not create parent directories for " "%s: %s" % (fileloc, err)) return try: open(fileloc, 'wb').write(contents) except IOError: err = sys.exc_info()[1] self.logger.error("Could not write %s: %s" % (fileloc, err)) return def verify_file(self, filename, contents, metadata): """ 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".""" entry = self.entries[metadata.hostname][filename] cfg = self.core.plugins['Cfg'] tries = 0 updated = False while not updated: if tries >= 10: self.logger.error("%s still not registered" % filename) return Bcfg2.Server.FileMonitor.get_fam().handle_events_in_interval(1) try: cfg.entries[filename].bind_entry(entry, metadata) except Bcfg2.Server.Plugin.PluginExecutionError: tries += 1 continue # get current entry data if entry.get("encoding") == "base64": entrydata = b64decode(entry.text) else: entrydata = entry.text if entrydata == contents: updated = True tries += 1 def write_infoxml(self, infoxml, data): """ write an info.xml for the file """ if os.path.exists(infoxml): return self.logger.info("Writing %s for %s" % (infoxml, data.get("name"))) default_mdata = Bcfg2.Server.Plugin.default_path_metadata() info = lxml.etree.Element( "Info", owner=data.get("owner", default_mdata['owner']), group=data.get("group", default_mdata['group']), mode=data.get("mode", default_mdata['mode'])) root = lxml.etree.Element("FileInfo") root.append(info) try: root.getroottree().write(infoxml, xml_declaration=False, pretty_print=True) except IOError: err = sys.exc_info()[1] self.logger.error("Could not write %s: %s" % (infoxml, err)) return