MySQL bash

#!/bin/bash
#
### BEGIN INIT INFO
# Provides:          mysql
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Should-Start:      $network $named $time
# Should-Stop:       $network $named $time
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start and stop the mysql (Percona Server) daemon
# Description:       Controls the main MySQL (Percona Server) daemon "mysqld"
#                    and its wrapper script "mysqld_safe".
### END INIT INFO
#
set -e
set -u
${DEBIAN_SCRIPT_DEBUG:+ set -v -x}
PERCONA_PREFIX=/usr

test -x "${PERCONA_PREFIX}"/sbin/mysqld || exit 0

. /lib/lsb/init-functions

SELF=$(cd $(dirname $0); pwd -P)/$(basename $0)
CONF=/etc/mysql/my.cnf
MYADMIN="${PERCONA_PREFIX}/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf"

# priority can be overriden and "-s" adds output to stderr
ERR_LOGGER="logger -p daemon.err -t /etc/init.d/mysql -i"

# Safeguard (relative paths, core dumps..)
cd /
umask 077

# mysqladmin likes to read /root/.my.cnf. This is usually not what I want
# as many admins e.g. only store a password without a username there and
# so break my scripts.
export HOME=/etc/mysql/

## Fetch a particular option from mysql's invocation.
#
# Usage: void mysqld_get_param option
mysqld_get_param() {
    "${PERCONA_PREFIX}"/sbin/mysqld --print-defaults \
        | tr " " "\n" \
        | grep -- "--$1" \
        | tail -n 1 \
        | cut -d= -f2
}

## Do some sanity checks before even trying to start mysqld.
sanity_checks() {
  # check for config file
  # DISABLED: We do not install my.cnf
  #if [ ! -r /etc/mysql/my.cnf ]; then
  #  log_warning_msg "$0: WARNING: /etc/mysql/my.cnf cannot be read. See README.Debian.gz"
  #  echo                "WARNING: /etc/mysql/my.cnf cannot be read. See README.Debian.gz" | $ERR_LOGGER
  #fi

  # check for diskspace shortage
  datadir=`mysqld_get_param datadir`
  if LC_ALL=C BLOCKSIZE= df --portability $datadir/. | tail -n 1 | awk '{ exit ($4>4096) }'; then
    log_failure_msg "$0: ERROR: The partition with $datadir is too full!"
    echo                "ERROR: The partition with $datadir is too full!" | $ERR_LOGGER
    exit 1
  fi
}

## Checks if there is a server running and if so if it is accessible.
#
# check_alive insists on a pingable server
# check_dead also fails if there is a lost mysqld in the process list
#
# Usage: boolean mysqld_status [check_alive|check_dead] [warn|nowarn]
mysqld_status () {
    ping_output=`$MYADMIN ping 2>&1`; ping_alive=$(( ! $? ))

    ps_alive=0
    pidfile=`mysqld_get_param pid-file`
    if [ -f "$pidfile" ] && ps `cat $pidfile` >/dev/null 2>&1; then ps_alive=1; fi

    if [ "$1" = "check_alive"  -a  $ping_alive = 1 ] ||
       [ "$1" = "check_dead"   -a  $ping_alive = 0  -a  $ps_alive = 0 ]; then
    return 0 # EXIT_SUCCESS
    else
    if [ "$2" = "warn" ]; then
        echo -e "$ps_alive processes alive and '$MYADMIN ping' resulted in\n$ping_output\n" | $ERR_LOGGER -p daemon.debug
    fi
    return 1 # EXIT_FAILURE
    fi
}

#
# main()
#

case "${1:-''}" in
  'start')
    sanity_checks;
    # Start daemon
    log_daemon_msg "Starting MySQL (Percona Server) database server" "mysqld"
    if mysqld_status check_alive nowarn; then
       log_progress_msg "already running"
       log_end_msg 0
    else
        "${PERCONA_PREFIX}"/bin/mysqld_safe > /dev/null 2>&1 &
        # 6s was reported in #352070 to be too few when using ndbcluster
        for i in 1 2 3 4 5 6 7 8 9 10 11 12 13 14; do
                sleep 1
            if mysqld_status check_alive nowarn ; then break; fi
        log_progress_msg "."
        done
        if mysqld_status check_alive warn; then
                log_end_msg 0
            # Now start mysqlcheck or whatever the admin wants.
            output=$(/etc/mysql/debian-start)
        [ -n "$output" ] && log_action_msg "$output"
        else
            log_end_msg 1
        log_failure_msg "Please take a look at the syslog"
        fi
    fi
    ;;

  'stop')
    # * As a passwordless mysqladmin (e.g. via ~/.my.cnf) must be possible
    # at least for cron, we can rely on it here, too. (although we have
    # to specify it explicit as e.g. sudo environments points to the normal
    # users home and not /root)
    log_daemon_msg "Stopping MySQL (Percona Server)" "mysqld"
    if ! mysqld_status check_dead nowarn; then
      set +e
      shutdown_out=`$MYADMIN shutdown 2>&1`; r=$?
      set -e
      if [ "$r" -ne 0 ]; then
        log_end_msg 1
        [ "$VERBOSE" != "no" ] && log_failure_msg "Error: $shutdown_out"
        log_daemon_msg "Killing MySQL (Percona Server) by signal" "mysqld"
        killall -15 mysqld
            server_down=
        for i in 1 2 3 4 5 6 7 8 9 10; do
              sleep 1
              if mysqld_status check_dead nowarn; then server_down=1; break; fi
            done
          if test -z "$server_down"; then killall -9 mysqld; fi
      fi
        fi

        if ! mysqld_status check_dead warn; then
      log_end_msg 1
      log_failure_msg "Please stop MySQL (Percona Server) manually and read /usr/share/doc/percona-server-server-5.5/README.Debian.gz!"
      exit -1
    else
      log_end_msg 0
        fi
    ;;

  'restart')
    set +e; $SELF stop; set -e
    $SELF start
    ;;

  'reload'|'force-reload')
    log_daemon_msg "Reloading MySQL (Percona Server)" "mysqld"
    $MYADMIN reload
    log_end_msg 0
    ;;

  'status')
    if mysqld_status check_alive nowarn; then
      log_action_msg "$($MYADMIN version)"
    else
      log_action_msg "MySQL (Percona Server) is stopped."
      exit 3
    fi
    ;;

  *)
    echo "Usage: $SELF start|stop|restart|reload|force-reload|status"
    exit 1
    ;;
esac