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#!/usr/bin/python
#
# Copyright 2014 Canonical Ltd. All rights reserved
# Author: Chris Stratford <chris.stratford@canonical.com>
import os
import sys
import subprocess
import shutil
import tempfile
sys.path.insert(0, os.path.join(os.environ['CHARM_DIR'], 'lib'))
from charmhelpers.core import hookenv, host
from charmhelpers.fetch import apt_install, apt_update
from charmhelpers.contrib.charmsupport.nrpe import NRPE
from Cheetah.Template import Template
from Config import Config
hooks = hookenv.Hooks()
log = hookenv.log
conf = Config()
SERVICE = 'samhain'
requiredPkgs = [
"samhain",
]
scriptsToCopy = [
"check-safe-for-update.sh",
"samhain-summary.py",
]
APT_CONF = "/etc/apt/apt.conf.d/91samhain"
# This should list any files affected by the charm that may trigger an alert
samhainFiles = [
"/etc",
"/etc/samhain",
"/etc/samhain/samhainrc",
"/etc/apt/apt.conf.d",
APT_CONF,
"/etc/cron.d",
"/etc/cron.d/count-samhain-violations",
]
def jujuHeader():
header = ("#-------------------------------------------------#\n"
"# This file is Juju managed - do not edit by hand #\n"
"#-------------------------------------------------#\n")
return header
def fileFromTemplate(tmpl, dest, searchList):
template_file = os.path.join(hookenv.charm_dir(), "templates", tmpl)
t = Template(file=template_file, searchList=searchList)
with open(dest, "w") as f:
f.write(jujuHeader())
f.write(str(t))
os.chmod(dest, 0444)
def copyScripts():
if not os.path.exists(conf.scriptDir()):
host.mkdir(conf.scriptDir())
for script in scriptsToCopy:
src = os.path.join(hookenv.charm_dir(), "files", script)
dest = os.path.join(conf.scriptDir(), script)
shutil.copyfile(src, dest)
os.chmod(dest, 0755)
def updateLogrotate():
relation_data = {}
relation_data["logfiles"] = '{"samhain":{"path":"/var/log/samhain/samhain.log","when":"daily"}}'
if hookenv.relation_id():
hookenv.relation_set(None, relation_data)
else:
for r in hookenv.relation_ids("logrotate"):
hookenv.relation_set(r, relation_data)
def installPackages():
apt_update()
apt_install(requiredPkgs, options=['--force-yes'])
# Note: We can't enable the check on install, as that prevents other
# charms installed alongside it from installing packages (any config
# file changes would make the system unclean), so this has to be set
# manually after the system is up and running.
# Note also, there is no option to disable it. This is intentional.
def updateAptConf():
if conf.enableAptCheck() == "yes":
src = os.path.join(hookenv.charm_dir(), "files", "apt.conf")
shutil.copyfile(src, APT_CONF)
os.chmod(APT_CONF, 0644)
updateSamhain("partial")
def writeConfig():
tmpl_data = {}
tmpl_data["attributesDirs"] = conf.attributesDirs()
tmpl_data["attributesFiles"] = conf.attributesFiles()
tmpl_data["eventSeverity"] = conf.eventSeverity()
tmpl_data["growingLogfiles"] = conf.growingLogfiles()
tmpl_data["ignoreAdded"] = conf.ignoreAdded()
tmpl_data["ignoreMissing"] = conf.ignoreMissing()
tmpl_data["ignoreModified"] = conf.ignoreModified()
tmpl_data["ignoreAllDirs"] = conf.ignoreAllDirs()
tmpl_data["ignoreAllFiles"] = conf.ignoreAllFiles()
tmpl_data["ignoreNoneDirs"] = conf.ignoreNoneDirs()
tmpl_data["ignoreNoneFiles"] = conf.ignoreNoneFiles()
tmpl_data["logging"] = conf.logging()
tmpl_data["logfiles"] = conf.logfiles()
tmpl_data["mailRecipient"] = conf.mailRecipient()
tmpl_data["prelinkDirs"] = conf.prelinkDirs()
tmpl_data["prelinkFiles"] = conf.prelinkFiles()
tmpl_data["readOnlyDirs"] = conf.readOnlyDirs()
tmpl_data["readOnlyFiles"] = conf.readOnlyFiles()
config_path = "/etc/samhain/samhainrc"
fileFromTemplate("samhainrc.tmpl", config_path, tmpl_data)
os.chmod(config_path, 0444)
# The samhain init scripts don't seem to work well
# so we'll control it directly
def controlSamhain(cmd):
log("CHARM: samhain {}".format(cmd))
validCmds = ["start", "stop", "restart", "reload", "status"]
if cmd not in validCmds:
log("CHARM: {} is not a valid samhain option".format(cmd))
sys.exit(1)
# Restart doesn't apear to work
if cmd == "restart":
controlSamhain("stop")
controlSamhain("start")
# If it's not started when we call reload, start it instead
if cmd == "reload":
if subprocess.call(["samhain", "status"]) != 0:
cmd = "start"
command = ["samhain", cmd]
if subprocess.call(command, shell=False) != 0:
log("CHARM: Error running samhain {} command".format(cmd))
sys.exit(1)
# Update samhain's DB
def updateSamhain(type="full"):
command = ['samhain', '-t', 'update', '--foreground', '-m', 'none', '-l', 'none', '-s', 'none']
with tempfile.NamedTemporaryFile() as f:
for filename in samhainFiles:
f.write(filename + "\n")
f.flush()
if type == "partial":
command += ["--listfile={}".format(f.name)]
if subprocess.call(command, shell=False) != 0:
log("CHARM: Error updating samhain")
sys.exit(1)
def configureNrpe():
checkScript = "samhain-policy-violations.py"
nrpePath = "/usr/local/lib/nagios/plugins"
with open("/etc/cron.d/count-samhain-violations", "w") as f:
f.write("*/{} * * * * root /usr/local/sbin/check-safe-for-update.sh > /var/lib/nagios/samhain-policy-violations.txt\n".format(conf.nagiosCheckFrequency()))
src = os.path.join(hookenv.charm_dir(), "files", checkScript)
shutil.copyfile(src, os.path.join(nrpePath, checkScript))
os.chmod(os.path.join(nrpePath, checkScript), 0755)
nrpe_compat = NRPE()
nrpe_compat.add_check(
shortname="samhain-violations",
description="Check for Samhain policy violations",
check_cmd="{} -w {} -c {}".format(
os.path.join(nrpePath, checkScript),
conf.nagiosWarnLevel(),
conf.nagiosCritLevel())
)
nrpe_compat.write()
@hooks.hook("logrotate-relation-changed")
def logrotateRelationChanged():
log("CHARM: Changing logrotate relation for {}".format(conf.appName()))
updateLogrotate()
@hooks.hook("nrpe-external-master-relation-changed")
def nrpeExternalMasterRelationChanged():
log("CHARM: Changing nrpe-external-master relation for {}".format(conf.appName()))
configureNrpe()
@hooks.hook('install')
def install():
log("CHARM: Installing {}".format(conf.appName()))
installPackages()
copyScripts()
updateSamhain()
# Fix samhain log permissions to be world-readable
# (otherwise logstash can't get to them)
if not os.path.exists("/var/log/samhain"):
mkdir("/var/log/samhain")
if not os.path.exists("/var/log/samhain/samhain.log"):
with open("/var/log/samhain/samhain.log", "w") as f:
os.chmod("/var/log/samhain/samhain.log", 0644)
@hooks.hook('config-changed')
def config_changed():
config = hookenv.config()
for key in config:
if config.changed(key):
log("config['{}'] changed from {} to {}".format(
key, config.previous(key), config[key]))
config.save()
writeConfig()
controlSamhain("restart")
updateAptConf()
@hooks.hook('upgrade-charm')
def upgrade_charm():
log("CHARM: Upgrading {}".format(conf.appName()))
copyScripts()
updateAptConf()
@hooks.hook('start')
def start():
controlSamhain("start")
@hooks.hook('stop')
def stop():
controlSamhain("stop")
if __name__ == "__main__":
# execute a hook based on the name the program is called by
hooks.execute(sys.argv)
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