/usr/lib/python2.7/dist-packages/Bcfg2/Server/Plugins/FileProbes.py is in bcfg2-server 1.4.0~pre2+git141-g6d40dace6358-1.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 | """ 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
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