MySQL Monitor (like 'redis-cli MONITOR')

mysql_monitor.sh

#!/bin/bash
#
# Monitor MySQL queries
# @author Colin Mollenhour

set -e

mysql="mysql"
test="test"
bash="bash"
cp="cp"

if [[ -z $1 ]] && ! test -f /var/run/mysqld/mysqld.sock; then
  set -- "--docker"
fi
if [[ $1 =~ --docker|docker ]]; then
  if [[ $(docker ps --format '{{.Names}}' | grep mysql | wc -l) -eq 1 ]]; then
    container=$(docker ps --format '{{.Names}}' | grep mysql | head -n 1)
  else
    select container in $(docker ps --format '{{.Names}}' | grep mysql); do
      break
    done
  fi
  mysql="docker exec $container mysql"
  test="docker exec $container test"
  bash="docker exec -i $container bash"
  function _cp {
    echo "Using docker cp"
    docker cp "$container:$1" "$2"
  }
elif [[ -n $1 ]]; then
  mysql="$1"
  function _cp {
    cp -f "$1" "$2"
  }
fi

file=$($mysql -sN performance_schema -e 'SELECT Variable_Value FROM global_variables WHERE Variable_Name = "general_log_file"')
if ! $test -f $file; then
  datadir=$($mysql -sN performance_schema -e 'SELECT Variable_Value FROM global_variables WHERE Variable_Name = "datadir"')
  datadir=${datadir%/}
  if ! $test -f $datadir/$file; then
    $mysql -e "SET GLOBAL general_log = 'ON'"
    sleep 1
    if ! $test -f $datadir/$file; then
      echo "Could not locate general log file $file in $datadir."
      exit 1
    fi
  fi
  file=$datadir/$file
fi

if ! $test -w $file  && [[ $bash = "bash" ]]; then
  bash="sudo bash"
fi

$bash -c ">$file"
$mysql -e "SET GLOBAL general_log = 'ON'"

tailPid=0
function cleanExit {
  kill -TERM $tailPid >/dev/null 2>&1
  $mysql -e "SET GLOBAL general_log = 'OFF'"
  tempfile=$(mktemp -p /tmp mysql-XXXXX.log)
  _cp $file $tempfile
  echo -e "\n$tempfile"
}

trap cleanExit SIGINT SIGTERM
$bash -c "tail -f $file" &
tailPid=$!
wait

$mysql -e "SET GLOBAL general_log = 'OFF'"
tempfile=$(mktemp -p /tmp mysql-XXXXX.log)
_cp $file $tempfile
echo -e "\n$tempfile"