#! /bin/bash
#
# Scripts to run by Percona Server systemd service
# 
# Needed argument: pre | post
# 
# pre mode  :  try to run mysql_install_db and fix perms and SELinux contexts
# post mode :  ping server until answer is received
# 

parse_cnf()
{
    local var=$1
    shift
    local groups=$*
    reval=$(my_print_defaults $groups | awk -F= '{if ($1 ~ /_/) { gsub(/_/,"-",$1); print $1"="$2 } else { print $0 }}' | grep -- "--$var=" | cut -d= -f2- | tail -n 1 )
    if [[ -z ${reval:-} ]];then 
        reval=""
    fi
    echo $reval
}

install_db () {    
    # Note: something different than datadir=/var/lib/mysql requires SELinux policy changes (in enforcing mode)
    log=$(parse_cnf log-error server mysqld mysqld_safe)
    datadir=$(parse_cnf datadir server mysqld)
    if [[ -z ${datadir:-} ]]; then
        datadir="/var/lib/mysql"
    fi

    # Check that pid-file directory exists and has valid permissions
    pid_path=$(parse_cnf pid-file server mysqld mysqld_safe)
    if [[ -z "${pid_path:-}" ]]; then
      pid_path=$datadir/`hostname`.pid
    else
      case "$pid_path" in
        /* ) ;;
        * )  pid_path="$datadir/$pid_path" ;;
      esac
    fi
    pidfiledir=$(dirname $pid_path)

    if [ ! -z $pidfiledir ]; then
        [ -d "$pidfiledir" ] || install -d -m 0755 -omysql -gmysql "$pidfiledir" || exit 1
    fi
    
    # Restore log, dir, perms and SELinux contexts
    [ -d "$datadir" ] || install -d -m 0755 -omysql -gmysql "$datadir" || exit 1
    if [ -x /usr/sbin/restorecon ]; then
        /usr/sbin/restorecon "$datadir"
        if [ ! -z $pidfiledir ]; then
            /usr/sbin/restorecon "$pidfiledir"
        fi
    fi

    # If log file is not specified it's put into datadir by default
    if [ ! -z $log ]; then
        if [ ! -f $log ]; then
            install -m 0640 -omysql -gmysql /dev/null $log
        fi
        if [ -x /usr/sbin/restorecon ]; then
            /usr/sbin/restorecon $log
        fi
    fi

    # If special mysql dir is in place, skip db install 
    [ -d "$datadir/mysql" ] && exit 0

    # Create initial db
    /usr/bin/mysql_install_db --rpm --datadir="$datadir" --user=mysql
    exit 0
}

pinger () {
    # Wait for ping to answer to signal startup completed,
    # might take a while in case of e.g. crash recovery
    # MySQL systemd service will timeout script if no answer
    datadir=$(parse_cnf datadir server mysqld)
    if [[ -z ${datadir:-} ]]; then
        datadir="/var/lib/mysql"
    fi
    socket=$(parse_cnf socket server mysqld)
    case $socket in
        /*) adminsocket="$socket" ;;
        "") adminsocket="$datadir/mysql.sock" ;;
        *) adminsocket="$datadir/$socket" ;;
    esac

    while /bin/true ; do
        sleep 1
        mysqladmin --socket="$adminsocket" ping >/dev/null 2>&1 && break
    done
    exit 0
}

# main
case $1 in
    "pre") install_db ;;
    "post") pinger ;;
esac

exit 0

