check_last_backup

#! /usr/bin/env bash

###############################################################################
# Monitor DB2 with Nagios
# Copyright 2013,2014,2015 Andres Gomez Casanova
# https://github.com/angoca/monitor-db2-with-nagios
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
###############################################################################

# This scripts checks the elderly of the last backup. It throws alerts if the
# last backups are too old.
#
# In order to be used in Nagios, you have to configure the following.
#
# # 'check_last_backup' command definition
# define command {
#         command_name    check_last_backup
#         command_line    $USER1$/check_by_ssh -H $HOSTADDRESS$ -l nagios -C "scripts/check_last_backup -i '$ARG1$' -d '$ARG2$' -w '$ARG3$' -c '$ARG4$'"
# }
# define service{
#         host_name               db2server
#         service_description     Last backup
#         check_command           check_last_backup!/home/db2inst1!sample!240:140:50!168:96:25
#         use                     generic-service
# }
#
# When using NRPE:
#
# In the database server:
#
# command[check_last_backup]=/home/nagios/scripts/check_last_backup -i /home/db2inst1 -d sample -c 240:140:50 -w 168:96:25
#
# Then modify the path according to your script location, instance home dir,
# database and thresholds.
#
# In the Nagios server:
#
# define service{
#         host_name               db2server
#         service_description     Last backup
#         check_command           check_nrpe_1arg!check_last_backup
#         use                     generic-service
# }
#
# Parameters:
# -c | --critical : Time in hours to consider the last backup age as critical.
#    This checks the full, incremental and delta backups.
#    Notation for these three type are times separated by colons
#    FF:II:DD = Full : Incremental : Delta.
#    Full is obligatory, other two are optionals.
# -d | --database : Database name.
# -h | --help : Show the help of this script.
# -i | --instance : Home directory of the instance. Usually it is
#   /home/db2inst1.
# -K | --mk : Change the output for Check_MK.
# -T | --trace : Trace mode. Writes output in /tmp.
# -v | --verbose : Execute the program in verbose mode.
# -V | --version : Show the current version of this script.
# -w | --warning : Time in hours to consider the last backup age as critical.
#    This checks the full, incremental and delta backups.
#
# Notation for these three type are times separated by colons
#    FF:II:DD = Full : Incremental : Delta.
#    Full is obligatory, other two are optionals.
#
# In AIX, the long name options are not supported.
#
# The exit codes are the standard for Nagios.
#
# 0 The plugin was able to check the service and it appeared to be functioning
#   properly.
# 1 The plugin was able to check the service, but it appeared to be above some
#   "warning" threshold or did not appear to be working properly.
# 2 The plugin detected that either the service was not running or it was above
#   some "critical" threshold.
# 3 Invalid command line arguments were supplied to the plugin or low-level
#   failures internal to the plugin (such as unable to fork, or open a tcp
#   socket) that prevent it from performing the specified operation.
#   Higher-level errors (such as name resolution errors, socket timeouts, etc)
#   are outside of the control of plugins and should generally NOT be reported
#   as UNKNOWN states.
#
# Author: Andres Gomez Casanova
# Version: v1.2 2015-10-15

# Flag for debugging.
#set -xv

# Locale to print messages in English. Prevent language problems.
export LANG=en_US

# Version of this script.
function print_revision {
  echo Andres Gomez Casanova - AngocA
  echo v1.2 2015-10-15
}
# Function to show the help
function print_usage {
  /bin/cat <<__EOT
Usage: ${1} { -i instanceHomeDirectory -d databaseName [-c][-w][-K]

| -h | -V }[-T][-v]
__EOT
}

function print_help {
  print_revision
  print_usage ${1}
  # Max 80 chars width.
  /bin/cat <<__EOT
-------------------------------------------------------------------------------
Checks the elderly of the last backup of the database.
-c | --critical INTEGER:INTEGER:INTEGER
   Time in hours of the last backup to considered as critical.
   Default 2.
-d | --database STRING
   Database name.
-h | --help
   Shows the current documentation.
-i | --instance STRING
   Instance home directory. It is usually /home/db2inst1.
-K | --mk
   Changes the output to be compatible with Check_MK.
-T | --trace
   Trace mode: writes date and output in /tmp.
-v | --verbose
   Executes the script in verbose mode (multiple times).
-V | --version
   Shows the current version of this script.
-w | --warning INTEGER:INTEGER:INTEGER
   Time in hours of the last backup to considered as warning.
   Default 1.
__EOT
}

function query {
  PARAM=${1}
  RET=1

  if [[ ${VERBOSE} -ge 2 ]] ; then
    echo "Params: '${PARAM}'"
  fi
  COMMAND_LIST="db2 -x 
with hist(start_time, operationtype) as (
 select start_time, operationtype
 from sysibmadm.db_history
 where operation = 'B' )
select timestampdiff(8, current timestamp - char(timestamp(max(start_time))))
from hist
where operationtype in (${PARAM})
order by 1"
  if [[ ${VERBOSE} -ge 2 ]] ; then
    echo "COMMAND: ${COMMAND_LIST}"
  fi
  LIST=$(db2 connect to ${DATABASE_NAME} > /dev/null ; ${COMMAND_LIST} ; db2 connect reset > /dev/null)
  if [[ ${VERBOSE} -ge 3 ]] ; then
    echo "RESULT:'${LIST}'"
  fi
  if [[ ${TRACE} == true ]] ; then
    echo "RESULT:'${LIST}'" >> ${LOG}
  fi
  # Check for errors
  CONN_ERROR=$(echo ${LIST} | grep SQL1024)
  HIST_ERROR=$(echo ${LIST} | grep SQL2155)
  HADR_ERROR=$(echo ${LIST} | grep SQL1773)
  HADR_REPLAY=$(echo ${LIST} | grep SQL1224)
  if [[ ${CONN_ERROR} != "" ]] ; then
    OUTPUT="Connection problem"
    RETURN=${UNKNOWN}
    CONTINUE=false
  elif [[ ${HIST_ERROR} != "" ]] ; then
    OUTPUT="History file modified"
    RETURN=${UNKNOWN}
    CONTINUE=false
  elif [[ ${HADR_ERROR} != "" ]] ; then
    OUTPUT="Trying to update calculation in Standby database"
    RETURN=${UNKNOWN}
    CONTINUE=false
  elif [[ ${HADR_REPLAY} != "" ]] ; then
    OUTPUT="HADR replaying"
    RETURN=${UNKNOWN}
    CONTINUE=false
  elif [[ ${LIST} == "" ]] ; then
    OUTPUT="Empty output, check the command"
    RETURN=${UNKNOWN}
    CONTINUE=false
  else
    RET=0
  fi
  return ${RET}
}

# Variable to control the flow execution. Prevent Spaghetti code.
CONTINUE=true

# Nagios return codes
OK=0
WARNING=1
CRITICAL=2
UNKNOWN=3
# This is the returned code.
RETURN=${UNKNOWN}

# Nagios Output
# Text output 80 chars | Optional Perf Data Line 1
# Long text Line 1
# Long text Line 2 | Optional Perf Data Line 2
# Optional Perf Data Line 3
OUTPUT=
PERFORMANCE=
LONG_OUTPUT=
LONG_PERFORMANCE=
PERF_MK="-"

APPL_NAME=$(basename ${0})

echo "$(date +"%Y-%m-%d-%H.%M.%S") $$ Started ${APPL_NAME} $@" >> /tmp/${APPL_NAME}.log

# Checks the lock file does not exist.
# The lock file is the way the command was called with its parameters
# without spaces.
COPY_ARGS=("${@}") 
LOCK_FILE=
for VALUE in "${COPY_ARGS[@]}" ; do
  LOCK_FILE="${LOCK_FILE}${VALUE}"
done
LOCK_FILE=${LOCK_FILE//\//}
LOCK_FILE=${LOCK_FILE//\\/}
LOCK_FILE=${LOCK_FILE//\:/}
LOCK_FILE=${LOCK_FILE//\*/}
LOCK_FILE=${LOCK_FILE//\|/}
LOCK_FILE="/tmp/${APPL_NAME}${LOCK_FILE}.lock"
if [[ ! -r ${LOCK_FILE} ]] ; then
  echo $$ > ${LOCK_FILE}
  LOCKED=true
else
  # If it exist, then check if the process is running.
  EXIST=$(ps -ef | grep $(cat ${LOCK_FILE}) | grep ${APPL_NAME})
  # If process is not running, delete it.
  if [[ ${EXIST} == "" ]] ; then
    rm ${LOCK_FILE}
    if [[ ! -r ${LOCK_FILE} ]] ; then
      echo $$ > ${LOCK_FILE}
      LOCKED=true
    else
      OUTPUT="The lock file cannot be replaced: ${LOCK_FILE}"
      CONTINUE=false
      RETURN=${UNKNOWN}
    fi
  else
    OUTPUT="An instance of the script with the same parameters is already running."
    CONTINUE=false
    RETURN=${UNKNOWN}
  fi
fi

if [[ ${#} -eq 0 ]] ; then
  print_usage ${APPL_NAME}
  RETURN=${UNKNOWN}
  CONTINUE=false
fi

# Checks the operating system. geopt works different in AIX than in Linux.
OS=$(uname)

if [[ "${OS:0:5}" == "Linux" ]] ; then
  # The following requires GNU getopt. See the following discussion.
  # http://stackoverflow.com/questions/402377

  TEMP=$(getopt -o c:d:hi:KTvVw: --long critical:,database:,help,instance:,mk,trace,verbose,version,warning: \
               -n ${APPL_NAME} -- "${@}")
elif [[ "${OS:0:3}" == "AIX" ]] ; then
  set -- $(getopt c:d:hi:KTvVw: ${*})
elif [[ "${OS:0:6}" == "Darwin" || "${OS:0:5}" == "SunOS" || "${OS:0:5}" == "HP-UX" ]] ; then
  echo "This plugin is not yet supported in your platform."
  echo "Please create a ticket in GitHub if you want to enable your current platform."
  echo "https://github.com/angoca/monitor-db2-with-nagios/issues"
  RETURN=${UNKNOWN}
  CONTINUE=false
elif [[ "${OS:0:6}" == "CYGWIN" ]] ; then
  echo "This plugin is not supported in Cygwin"
  RETURN=${UNKNOWN}
  CONTINUE=false
else
  echo "The platform is unknown: ${OS}"
  echo "Please create a ticket in GitHub: https://github.com/angoca/monitor-db2-with-nagios/issues"
  RETURN=${UNKNOWN}
  CONTINUE=false
fi

if [[ ${?} -ne 0 ]] ; then
  print_usage ${APPL_NAME}
  RETURN=${UNKNOWN}
  CONTINUE=false
fi

if [[ ${CONTINUE} == true ]] ; then
  if [[ "${OS}" == "Linux" ]] ; then
    # Note the quotes around ${TEMP}: they are essential!
    eval set -- "${TEMP}"
  fi
  HELP=false
  VERSION=false
  CHECK_MK=false
  # Verbosity level
  VERBOSE=0
  # Trace activated
  TRACE=false
  LOG=/tmp/${APPL_NAME}.log
  INSTANCE_HOME=
  DATABASE_NAME=
  WARNING_THRES=
  CRITICAL_THRES=
  if [[ "${OS:0:5}" == "Linux" ]] ; then
    while true; do
      case "${1}" in
        -c | --critical ) CRITICAL_THRES=$(echo ${2} | cut -d' ' -f1) ; shift 2 ;;
        -d | --database ) DATABASE_NAME=$(echo ${2} | cut -d' ' -f1) ; shift 2 ;;
        -h | --help ) HELP=true ; shift ;;
        -i | --instance ) INSTANCE_HOME=$(echo ${2} | cut -d' ' -f1) ; shift 2 ;;
        -K | --mk ) CHECK_MK=true ; shift ;;
        -T | --trace ) TRACE=true ; shift ;;
        -v | --verbose ) VERBOSE=$(( ${VERBOSE} + 1 )) ; shift ;;
        -V | --version ) VERSION=true ; shift ;;
        -w | --warning ) WARNING_THRES=$(echo ${2} | cut -d' ' -f1) ; shift 2 ;;
        -- ) shift ; break ;;
        * ) break ;;
      esac
    done
  elif [[ "${OS:0:3}" = "AIX" ]] ; then
    while [[ $1 != -- ]] ; do
      case "${1}" in
        -c) CRITICAL_THRES=$(echo ${2} | cut -d' ' -f1) ; shift 2 ;;
        -d) DATABASE_NAME=$(echo ${2} | cut -d' ' -f1) ; shift 2 ;;
        -h) HELP=true ; shift ;;
        -i) INSTANCE_HOME=$(echo ${2} | cut -d' ' -f1) ; shift 2 ;;
        -K) CHECK_MK=true ; shift ;;
        -T) TRACE=true ; shift ;;
        -v) VERBOSE=$(( ${VERBOSE} + 1 )) ; shift ;;
        -V) VERSION=true ; shift ;;
        -w) WARNING_THRES=$(echo ${2} | cut -d' ' -f1) ; shift 2 ;;
        * ) break ;;
      esac
    done
  fi
fi

if [[ ${TRACE} == true ]] ; then
  echo ">>>>>" >> ${LOG}
  date >> ${LOG}
  echo "Instance at ${INSTANCE_HOME}" >> ${LOG}
  echo "PID ${$}" >> ${LOG}
fi

ECHO="help:${HELP}, version:${VERSION}, verbose:${VERBOSE}"
ECHO="${ECHO}, directory:${INSTANCE_HOME}, database:${DATABASE_NAME}"
ECHO="${ECHO}, warning:${WARNING_THRES}, critical:${CRITICAL_THRES}"
ECHO="${ECHO}, check_mk:${CHECK_MK}"

if [[ ${VERBOSE} -ge 2 ]] ; then
  echo ${ECHO}
fi

if [[ ${TRACE} == true ]] ; then
  echo "PARAMS:${ECHO}" >> ${LOG}
fi

if [[ ${CONTINUE} == true && ${HELP} == true ]] ; then
  print_help ${APPL_NAME}
  RETURN=${UNKNOWN}
  CONTINUE=false
fi

if [[ ${CONTINUE} == true && ${VERSION} == true ]] ; then
  print_revision ${APPL_NAME}
  RETURN=${UNKNOWN}
  CONTINUE=false
fi

if [[ ${CONTINUE} == true && ${INSTANCE_HOME} == "" ]] ; then
  print_usage ${APPL_NAME}
  RETURN=${UNKNOWN}
  CONTINUE=false
fi

if [[ ${CONTINUE} == true && ${DATABASE_NAME} == "" ]] ; then
  print_usage ${APPL_NAME}
  RETURN=${UNKNOWN}
  CONTINUE=false
fi

if [[ ${CONTINUE} == true ]] ; then
  CRIT_FULL=$(echo ${CRITICAL_THRES} | awk -F: '{print $1}')
  CRIT_INCR=$(echo ${CRITICAL_THRES} | awk -F: '{print $2}')
  CRIT_DELT=$(echo ${CRITICAL_THRES} | awk -F: '{print $3}')
  WARN_FULL=$(echo ${WARNING_THRES} | awk -F: '{print $1}')
  WARN_INCR=$(echo ${WARNING_THRES} | awk -F: '{print $2}')
  WARN_DELT=$(echo ${WARNING_THRES} | awk -F: '{print $3}')

  if [[ ${WARNING_THRES} == "" || ${CRITICAL_THRES} == ""
      || ${WARN_FULL} == "" || ${CRIT_FULL} == ""
      || ${WARN_FULL} -le 0 || ${CRIT_FULL} -le 0
      || ${WARN_FULL} -ge ${CRIT_FULL} 
      || ( ${WARN_INCR} != "" && ${CRIT_INCR} == "" )
      || ( ${WARN_INCR} == "" && ${CRIT_INCR} != "" )
      || ( ${WARN_INCR} != "" && ${CRIT_INCR} != ""
      && ( ${WARN_INCR} -le 0 || ${CRIT_INCR} -le 0
      || ${WARN_INCR} -ge ${CRIT_INCR} ))
      || ( ${WARN_DELT} != "" && ${CRIT_DELT} == "" )
      || ( ${WARN_DELT} == "" && ${CRIT_DELT} != "" )
      || ( ${WARN_DELT} != "" && ${CRIT_DELT} != ""
      && ( ${WARN_DELT} -le 0 || ${CRIT_DELT} -le 0
      || ${WARN_DELT} -ge ${CRIT_DELT} )) ]] ; then
    print_usage ${APPL_NAME}
    echo "Warning threshold should be less than critical threshold."
    echo "Threshold should be greater than 0."
    RETURN=${UNKNOWN}
    CONTINUE=false
  fi
fi

if [[ ${CONTINUE} == true ]] ; then
  if [[ -d ${INSTANCE_HOME} && -e ${INSTANCE_HOME}/sqllib/db2profile ]] ; then
    # Load the DB2 profile.
    . ${INSTANCE_HOME}/sqllib/db2profile
    INSTANCE_NAME=$(db2 get instance | awk '/instance/ {print $7}')
  else
    OUTPUT="Instance directory is invalid."
    RETURN=${UNKNOWN}
    CONTINUE=false
  fi
fi

if [[ ${CONTINUE} == true ]] ; then
  COMMAND_DATABASE="db2 list db directory"
  if [[ ${VERBOSE} -ge 2 ]] ; then
    echo "COMMAND: ${COMMAND_DATABASE}"
  fi
  DATABASE=$(${COMMAND_DATABASE})
  if [[ ${TRACE} == true ]] ; then
    echo "RESULT:'${DATABASE}'" >> ${LOG}
  fi
  DATABASE=$(printf '%s\n' "${DATABASE}" | awk '/Database alias/ {print $4}' | grep -iw ${DATABASE_NAME})
  if [[ ${VERBOSE} -ge 3 ]] ; then
    echo "RESULT:'${DATABASE}'"
  fi
  if [[ ${DATABASE} == "" ]] ; then
    OUTPUT="The database ${DATABASE_NAME} is not catalogued."
    RETURN=${UNKNOWN}
    CONTINUE=false
  fi
fi

if [[ ${CONTINUE} == true ]] ; then
  # Checks HADR role.
  HADR_ROLE=$(db2 get db cfg for wfscpd | awk '/HADR database role/ {print $5}')
  if [[ ${VERBOSE} -ge 3 ]] ; then
    echo "RESULT HADR: '${HADR_ROLE}'"
  fi
  # There could be just one query, but 'union all' is no allowed in HADR, thus 
  # three calls.
  # There is a problem when accessing the db_view, and the script hangs in any
  # of the three calls.
  if [[ ! -z ${CRIT_DELT} ]] ; then
    query "'D', 'E', 'I', 'O', 'F', 'N'"
    RET1=${?}
    DELTA=${LIST}
    if [[ ${RET1} -eq 0 ]] ; then
      DIFF_DELT=$(echo ${DELTA} | awk '{print $1}')
      if [[ ${HADR_ROLE} != "STANDBY" ]] ; then
        if [[ ${DIFF_DELT} -ge ${CRIT_DELT} ]] ; then
          OUTPUT="Delta backup is too old."
          RETURN=${CRITICAL}
        elif [[ ${DIFF_DELT} -ge ${WARN_DELT} ]] ; then
          OUTPUT="Delta backup is getting old."
          if [[ ${RETURN} -ne ${CRITICAL} ]] ; then
            RETURN=${WARNING}
          fi
        else
          OUTPUT="OK Delta."
        fi
      fi
    fi
  fi
fi

if [[ ${CONTINUE} == true ]] ; then
  if [[ ! -z ${CRIT_INCR} ]] ; then
    query "'I', 'O', 'F', 'N'"
    RET2=${?}
    INCREMENTAL=${LIST}
    if [[ ${RET2} -eq 0 ]] ; then
      DIFF_INCR=$(echo ${INCREMENTAL} | awk '{print $1}')
      if [[ ${HADR_ROLE} != "STANDBY" ]] ; then
        if [[ ${DIFF_INCR} -ge ${CRIT_INCR} ]] ; then
          OUTPUT="Incremental backup is too old. ${OUTPUT}"
          RETURN=${CRITICAL}
        elif [[ ${DIFF_INCR} -ge ${WARN_INCR} ]] ; then
           OUTPUT="Incremental backup is getting old. ${OUTPUT}"
          if [[ ${RETURN} -ne ${CRITICAL} ]] ; then
            RETURN=${WARNING}
          fi
        else
          OUTPUT="OK Incremental. ${OUTPUT}"
        fi
      fi
    fi
  fi
fi

if [[ ${CONTINUE} == true ]] ; then
  query "'F', 'N'"
  RET3=${?}
  FULL=${LIST}
  if [[ ${RET3} -eq 0 ]] ; then
    DIFF_FULL=$(echo ${FULL} | awk '{print $1}')
    if [[ ${HADR_ROLE} != "STANDBY" ]] ; then
      if [[ ${DIFF_FULL} -ge ${CRIT_FULL} ]] ; then
        OUTPUT="Full backup is too old. ${OUTPUT}"
        RETURN=${CRITICAL}
      elif [[ ${DIFF_FULL} -ge ${WARN_FULL} ]] ; then
        OUTPUT="Full backup is getting old. ${OUTPUT}"
        RETURN=${WARNING}
      else
        OUTPUT="OK Full. ${OUTPUT}"
        RETURN=${OK}
      fi
    else
      OUTPUT="OK. Standby database, check values in primary."
      RETURN=${OK}
    fi

    # Performance data
    PERFORMANCE="'Full_backup'=${DIFF_FULL};${WARN_FULL};${CRIT_FULL}"
    if [[ ! -z ${CRIT_DELT} ]] ; then
      DELTA_PERF="'Delta_backup'=${DIFF_DELT};${WARN_DELT};${CRIT_DELT}"
    fi
    if [[ ! -z ${CRIT_INCR} ]] ; then
      INCR_PERF="'Incremental_backup'=${DIFF_INCR};${WARN_INCR};${CRIT_INCR}"
    fi
    LONG_PERFORMANCE="${DELTA_PERF}\n${INCR_PERF}"
    PERF_MK="${INCR_PERF}|${DELTA_PERF}|${INCR_PERF}"
  else
    OUTPUT="There are problems retrieving the data."
    RETURN=${UNKNOWN}
  fi
fi

# Prints the output.
if [[ ${OUTPUT} == "" ]] ; then
  OUTPUT="Note: The test was not executed."
fi
# Builds the output.
if [[ ${CHECK_MK} == true ]] ; then
  echo "${RETURN} lastBackup-${INSTANCE_NAME}-${DATABASE_NAME} ${PERF_MK} ${OUTPUT}"
else
  echo -e "${OUTPUT}|${PERFORMANCE}\n${LONG_OUTPUT}|${LONG_PERFORMANCE}"
fi
# Returns the error code.
if [[ ${VERBOSE} -ge 2 ]] ; then
  echo "Return code: ${RETURN}"
fi
if [[ ${TRACE} == true ]] ; then
  echo -e "OUTPUT:${OUTPUT}\nPERF:${PERFORMANCE}\nLONG_OUT:${LONG_OUTPUT}\nLONGPERF:${LONG_PERFORMANCE}\nRET_CODE:${RETURN}" >> ${LOG}
  date >> ${LOG}
  echo -e "<<<<<\n" >> ${LOG}
fi

if [[ ${LOCKED} == true && -r ${LOCK_FILE} ]] ; then
  rm ${LOCK_FILE}
fi

echo "$(date +"%Y-%m-%d-%H.%M.%S") $$ Ended ${APPL_NAME} ${COPY_ARGS[@]}" >> /tmp/${APPL_NAME}.log

exit ${RETURN}