#!/bin/bash
#
# kill-thread.sh [options]
#  - Kill database connections based on options
#
# Changelog:
#  * 2014-05-23 - Nathan Isburgh <nathan@edgecloud.com>
#               - Initial version of script
#

# Debug flag - 1 for verbose debugging
DEBUG=1

#
# NO EDITS BELOW THIS LINE
#

#
# succeed()
#  - gracefully exit from program successfully
#
succeed() {
  cleanup
  exit 0
}

#
# fail( code, msg )
#  - gracefully exit from program in failure state
#
fail() {
  cleanup
  if [ -n "$2" ]
  then
    echo "$2" > /dev/stderr
  fi
  exit ${1:-1}
}

#
# cleanup()
#  - clean up log/lock files, etc
#
cleanup() {
  return
}

#
# debug( msg )
#  - Prints standard debug message to stderr
#  - Only print if debugging is enabled
#
debug() {
  if [ "$DEBUG" -ne 1 ]
  then
    return
  fi
  echo $(date +%T) " $@" > /dev/stderr
}

#
# usage()
#  - Print a basic usage statement for user to understand program use
#
usage() {
  cat << eof
Usage:
    $0 [-u user] [-h host] [-d db] [-c command]
   Kill database connections based on one or more attributes
 -u user     Kill by connected user
 -h host     Kill connections from host
 -d db       Kill connections to database db
 -c command  Kill connections currently executing command
eof
}

kill-thread() {
# 3 	root	localhost	mysql	
  mysql -se "show full proCESslIst" | fgrep -v proCESslIst | awk -F'\t' '$2 ~ /'$FUSER'/ && $3 ~ /'$FHOST'/ && $4 ~ /'$FDB'/ && $8 ~ /'$FCMD'/ {print $1}' | xargs -rn 1 mysqladmin kill
}

# Main code body
# ...

FUSER=''
FHOST=''
FDB=''
FCMD=''

while getopts ":u:h:d:c:" opt; do
  case $opt in
    u)
      debug "user filter requested: '$OPTARG'"
      FUSER="$OPTARG"
      ;;
    h)
      debug "host filter requested: '$OPTARG'"
      FHOST="$OPTARG"
      ;;
    d)
      debug "db filter requested: '$OPTARG'"
      FDB="$OPTARG"
      ;;
    c)
      debug "command filter requested: '$OPTARG'"
      FCMD="$OPTARG"
      ;;
    \?)
      usage
      fail 1 "Invalid option: -$OPTARG"
      ;;
    :)
      usage
      fail 2 "Option -$OPTARG requires an argument."
      ;;
  esac
done

kill-thread

succeed