1#!/bin/sh 2 3# ######################################################################## 4# This program is part of $PROJECT_NAME$ 5# License: GPL License (see COPYING) 6# Authors: 7# Baron Schwartz 8# ######################################################################## 9 10# ######################################################################## 11# Redirect STDERR to STDOUT; Nagios doesn't handle STDERR. 12# ######################################################################## 13exec 2>&1 14 15# ######################################################################## 16# Set up constants, etc. 17# ######################################################################## 18STATE_OK=0 19STATE_WARNING=1 20STATE_CRITICAL=2 21STATE_UNKNOWN=3 22STATE_DEPENDENT=4 23 24# ######################################################################## 25# Run the program. 26# ######################################################################## 27main() { 28 # Get options 29 for o; do 30 case "${o}" in 31 -c) shift; OPT_CRIT="${1}"; shift; ;; 32 --defaults-file) shift; OPT_DEFT="${1}"; shift; ;; 33 -H) shift; OPT_HOST="${1}"; shift; ;; 34 -l) shift; OPT_USER="${1}"; shift; ;; 35 -L) shift; OPT_LOPA="${1}"; shift; ;; 36 -p) shift; OPT_PASS="${1}"; shift; ;; 37 -P) shift; OPT_PORT="${1}"; shift; ;; 38 -S) shift; OPT_SOCK="${1}"; shift; ;; 39 -w) shift; OPT_WARN="${1}"; shift; ;; 40 --version) grep -A2 '^=head1 VERSION' "$0" | tail -n1; exit 0 ;; 41 --help) perl -00 -ne 'm/^ Usage:/ && print' "$0"; exit 0 ;; 42 -*) echo "Unknown option ${o}. Try --help."; exit 1; ;; 43 esac 44 done 45 if [ -e '/usr/local/etc/nagios/mysql.cnf' ]; then 46 OPT_DEFT="${OPT_DEFT:-/usr/local/etc/nagios/mysql.cnf}" 47 fi 48 if is_not_sourced; then 49 if [ -n "$1" ]; then 50 echo "WARN spurious command-line options: $@" 51 exit 1 52 fi 53 fi 54 55 # Set the exit status in case there are any problems. 56 NOTE="UNK could not determine the PID file location." 57 58 # Set up files to hold one or more PID file locations. 59 local TEMP=$(mktemp -t "${0##*/}.XXXXXX") || exit $? 60 local FILES=$(mktemp -t "${0##*/}.XXXXXX") || exit $? 61 trap "rm -f '${TEMP}' '${FILES}' >/dev/null 2>&1" EXIT 62 63 # If any connection option was given, then try to log in to find the PID 64 # file. 65 if [ "${OPT_DEFT}${OPT_HOST}${OPT_USER}${OPT_PASS}${OPT_PORT}${OPT_SOCK}" ]; then 66 # If this fails (e.g. we can't log in), then there will be no line in the 67 # file, and later we won't change the exit code / note away from "UNK". 68 if mysql_exec "SHOW GLOBAL VARIABLES" > "${TEMP}"; then 69 get_pidfile "${TEMP}" >> "${FILES}" 70 fi 71 else 72 # Find all MySQL server instances. 73 for pid in $(_pidof mysqld); do 74 ps -p ${pid} -o pid,command | grep "${pid}" >> "${TEMP}" 75 done 76 # The ${TEMP} file may now contain lines like the following sample: 77 # 13822 /usr/sbin/mysqld --defaults-file=/var/lib/mysql/my.cnf \ 78 # --basedir=/usr --datadir=/var/lib/mysql/data/ \ 79 # --pid-file=/var/run/mysqld/mysqld.pid \ 80 # --socket=/var/run/mysqld/mysqld.sock 81 # Now the task is to read find any reference to a --pid-file or --pid_file option. 82 # We store these into the $FILES temp file. 83 while read pid command; do 84 if echo "${command}" | grep pid.file >/dev/null 2>&1; then 85 # Strip off everything up to and including --pid-file= 86 command="${command##*--pid?file=}" 87 # Strip off any options that follow this, assuming that there's not 88 # a space followed by a dash in the pidfile's path. 89 echo "${command%% -*}" >> "${FILES}" 90 fi 91 done < "${TEMP}" 92 fi 93 94 # TODO: maybe in the future we can also check whether the PID in the file is 95 # correct. TODO: maybe we should also alert on which PID is missing its 96 # pidfile. 97 MISSING="" 98 NOTE2="" 99 while read pidfile; do 100 if [ ! -e "${pidfile}" ]; then 101 MISSING=1 102 NOTE2="${NOTE2:+${NOTE2}; }missing ${pidfile}" 103 fi 104 NOTE="OK all PID files exist." 105 done < "${FILES}" 106 107 if [ "${MISSING}" ]; then 108 if [ "${OPT_CRIT}" ]; then 109 NOTE="CRIT ${NOTE2}" 110 else 111 NOTE="WARN ${NOTE2}" 112 fi 113 fi 114 115 echo $NOTE 116} 117 118# ######################################################################## 119# Execute a MySQL command. 120# ######################################################################## 121mysql_exec() { 122 mysql ${OPT_DEFT:+--defaults-file="${OPT_DEFT}"} \ 123 ${OPT_LOPA:+--login-path="${OPT_LOPA}"} \ 124 ${OPT_HOST:+-h"${OPT_HOST}"} ${OPT_PORT:+-P"${OPT_PORT}"} \ 125 ${OPT_USER:+-u"${OPT_USER}"} ${OPT_PASS:+-p"${OPT_PASS}"} \ 126 ${OPT_SOCK:+-S"${OPT_SOCK}"} -ss -e "$1" 127} 128 129# ######################################################################## 130# A wrapper around pidof, which might not exist. The first argument is the 131# command name to match. 132# ######################################################################## 133_pidof() { 134 if ! pidof "${1}" 2>/dev/null; then 135 ps axo pid,ucomm | awk -v comm="${1}" '$2 == comm { print $1 }' 136 fi 137} 138 139# ######################################################################## 140# Unfortunately, MySQL 5.0 doesn't have a system variable @@pid_file, so 141# we have to use SHOW VARIABLES and a temp file. In 5.1 and newer we 142# could have done it in a single SQL statement: 143# SELECT IF(@@pid_file LIKE '/%', @@pid_file, 144# CONCAT(@@basedir, @@pid_file))" >> "${FILES}" 145# The first argument is the file that contains SHOW VARIABLES. 146# ######################################################################## 147get_pidfile() { 148 awk ' 149 /^pid_file/ { pid_file = $2 } 150 /^basedir/ { basedir = $2 } 151 END { 152 if ( substr(pid_file, 1, 1) != "/" ) { 153 pid_file = basedir pid_file; 154 } 155 print pid_file; 156 } 157 ' "$1" 158} 159 160# ######################################################################## 161# Determine whether this program is being executed directly, or sourced/included 162# from another file. 163# ######################################################################## 164is_not_sourced() { 165 [ "${0##*/}" = "pmp-check-mysql-pidfile" ] || [ "${0##*/}" = "bash" -a "$_" = "$0" ] 166} 167 168# ######################################################################## 169# Execute the program if it was not included from another file. 170# This makes it possible to include without executing, and thus test. 171# ######################################################################## 172if is_not_sourced; then 173 OUTPUT=$(main "$@") 174 EXITSTATUS=$STATE_UNKNOWN 175 case "${OUTPUT}" in 176 UNK*) EXITSTATUS=$STATE_UNKNOWN; ;; 177 OK*) EXITSTATUS=$STATE_OK; ;; 178 WARN*) EXITSTATUS=$STATE_WARNING; ;; 179 CRIT*) EXITSTATUS=$STATE_CRITICAL; ;; 180 esac 181 echo "${OUTPUT}" 182 exit $EXITSTATUS 183fi 184 185# ############################################################################ 186# Documentation 187# ############################################################################ 188: <<'DOCUMENTATION' 189=pod 190 191=head1 NAME 192 193pmp-check-mysql-pidfile - Alert when the mysqld PID file is missing. 194 195=head1 SYNOPSIS 196 197 Usage: pmp-check-mysql-pidfile [OPTIONS] 198 Options: 199 -c CRIT Critical threshold; makes a missing PID file critical. 200 --defaults-file FILE Only read mysql options from the given file. 201 Defaults to /usr/local/etc/nagios/mysql.cnf if it exists. 202 -H HOST MySQL hostname. 203 -l USER MySQL username. 204 -L LOGIN-PATH Use login-path to access MySQL (with MySQL client 5.6). 205 -p PASS MySQL password. 206 -P PORT MySQL port. 207 -S SOCKET MySQL socket file. 208 -w WARN Warning threshold; ignored. 209 --help Print help and exit. 210 --version Print version and exit. 211 Options must be given as --option value, not --option=value or -Ovalue. 212 Use perldoc to read embedded documentation with more details. 213 214=head1 DESCRIPTION 215 216This Nagios plugin checks to make sure that the MySQL PID file is not missing. 217The PID file contains the process ID of the MySQL server process, and is used by 218init scripts to start and stop the server. If it is deleted for some reason, 219then it is likely that the init script will not work correctly. The file can be 220deleted by poorly written scripts, an accident, or a mistaken attempt to restart 221MySQL while it is already running, especially if mysqld is executed directly 222instead of using the init script. 223 224The plugin accepts the -w and -c options for compatibility with standard Nagios 225plugin conventions, but they are not based on a threshold. Instead, the plugin 226raises a warning by default, and if the -c option is given, it raises an error 227instead, regardless of the option. 228 229By default, this plugin will attempt to detect all running instances of MySQL, 230and verify the PID file's existence for each one. It does this purely by 231examining the Unix process table with the C<ps> tool. However, in some cases 232the process's command line does not list the path to the PID file. If the tool 233fails to detect the MySQL server process, or if you wish to limit the check to a 234single instance in the event that there are multiple instances on a single 235server, then you can specify MySQL authentication options. This will cause the 236plugin to skip examining the Unix processlist, log into MySQL, and examine the 237pid_file variable from SHOW VARIABLES to find the location of the PID file. 238 239=head1 PRIVILEGES 240 241This plugin executes the following commands against MySQL: 242 243=over 244 245=item * 246 247C<SELECT> the system variables C<@@pid_file> and C<@@basedir>. 248 249=back 250 251This plugin executes the following UNIX commands that may need special privileges: 252 253=over 254 255=item * 256 257ps 258 259=back 260 261The plugin should be able to either get variables from MySQL or find mysqld 262PID using C<ps> command. 263 264On BSD, if C<sysctl> option C<security.bsd.see_other_uids> is set to 0, C<ps> 265will not return mysqld PID if the plugin run from non-root user. 266 267Also an user you run the plugin from should be able to access MySQL PID file 268file, so you may want to add it into mysql unix group etc. 269 270=head1 COPYRIGHT, LICENSE, AND WARRANTY 271 272This program is copyright 2012-$CURRENT_YEAR$ Baron Schwartz, 2012-$CURRENT_YEAR$ Percona Inc. 273Feedback and improvements are welcome. 274 275THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED 276WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 277MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 278 279This program is free software; you can redistribute it and/or modify it under 280the terms of the GNU General Public License as published by the Free Software 281Foundation, version 2. You should have received a copy of the GNU General 282Public License along with this program; if not, write to the Free Software 283Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. 284 285=head1 VERSION 286 287$PROJECT_NAME$ pmp-check-mysql-pidfile $VERSION$ 288 289=cut 290 291DOCUMENTATION 292