#!/usr/local/bin/python
#
# check_rdiff_backup: check liveness of a rdiff-backup repository
# Dan R. K. Ports <drkp@mit.edu>
#
# Copyright (c) 2007-2008 Dan R. K. Ports
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
#
# $Revision$ $Date$

import sys, os, re, popen2, optparse, glob, time
from datetime import datetime, timedelta
from time import strptime


#
# Nagios helpers
#

OK = 0
WARN = 1
CRIT = 2

stat = OK

def updateStat(x):
    global stat
    stat = max(stat,x)

msgs = []

#
# Options
#

parser = optparse.OptionParser()
parser.add_option("-d", "--dir", dest="path",
                  help="path to rdiff backup repository", metavar="PATH")
parser.add_option("-a", "--age", dest="days", type="float",
                  help="acceptable backup age (days)", metavar="DAYS")
parser.add_option("-r", "--runtime-warn", dest="runtimeWarn", type="float",
                  help="warning backup runtime (hours)", metavar="HOURS")
parser.add_option("-R", "--runtime-crit", dest="runtimeCrit", type="float",
                  help="critical backup runtime (hours)", metavar="HOURS")
parser.add_option("-s", "--min-size", dest="minSize", type="float",
                  help="minimum repository size (MB)", metavar="MB")
parser.add_option("-c", "--max-change", dest="maxChange", type="float",
                  help="warning changed size (MB)", metavar="MB")


(options, args) = parser.parse_args()



try:
    if not os.path.isdir(options.path):
        raise Exception("invalid repository directory")

    dataPath = os.path.join(options.path, "rdiff-backup-data")
    if not os.path.isdir(dataPath):
        raise Exception("no rdiff-backup-data directory")

    currentMirrors = glob.glob(os.path.join(dataPath, "current_mirror*"))
    currentMirrors.sort()

    if (len(currentMirrors) != 1 and len(currentMirrors) != 2):

        raise Exception("neither 1 nor 2 current mirrors")

    #
    # Check last successful backup
    # 
    timestamp = os.path.basename(currentMirrors[0]).split(".")[1]

    # Check freshness
    age = (time.time() - os.stat(currentMirrors[0]).st_mtime)/86400.0
    if (age > options.days):
        updateStat(CRIT)
        msgs.append("backup is %f days old" % age)

    # Check statistics
    statsFile = file(os.path.join(dataPath,
                                  "session_statistics." + timestamp +
                                  ".data"))
    stats = {}
    for x in statsFile:
        stats[x.split(" ")[0]] = " ".join(x.split(" ")[1:])

    sourceSize = int(stats["SourceFileSize"].split()[0])/1048576.0
    if (sourceSize < options.minSize):
        updateStat(CRIT)
        msgs.append("source file size dropped below %f MB: %f MB" %
                    (options.minSize, sourceSize))

    sizeChange = int(stats["TotalDestinationSizeChange"].split()[0])/1048576.0
    if (sizeChange > options.maxChange):
        updateStat(WARN)
        msgs.append("transferred more than %f MB: %f MB" %
                    (options.maxChange, sizeChange))

    #
    # Check backup progess
    #

    if len(currentMirrors) == 2:
        msgs.append("backup in progress")
        
        timestamp = os.path.basename(currentMirrors[1]).split(".")[1]

        pid = int(file(currentMirrors[1]).readline().split()[1])

        proc = popen2.Popen4("ps -w -o command= -p " + str(pid))
        if (proc.wait() != 0):
            raise Exception("failed to run ps")
        cmdline = proc.fromchild.readline()

        if not "rdiff-backup" in cmdline:
            updateStat(CRIT)
            msgs.append("backup interrupted!")

        # Check freshness
        age = (time.time() - os.stat(currentMirrors[1]).st_mtime)/3600.0
        if (age > options.runtimeCrit):
            updateStat(CRIT)
            msgs.append("backup has been in progress for %f hours" % age)
        elif (age > options.runtimeWarn):
            updateStat(WARN)
            msgs.append("backup has been in progress for %f hours" % age)

    
    
except Exception, e:
    msgs.append(str(e))
    updateStat(CRIT)

if stat == OK:
    out = "OK "
elif stat == WARN:
    out = "WARN "
else:
    out = "CRIT "
    
out += "; ".join(msgs)
print out
sys.exit(stat)