#! /bin/bash

# Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA


# Script used by systemd mysqld.service to run before executing mysqld

get_option () {
    local section=$1
    local option=$2
    local default=$3
    local instance=$4
    ret=$(/usr/bin/my_print_defaults  ${instance:+--defaults-group-suffix=@$instance} $section | \
              grep '^--'${option}'=' | cut -d= -f2- | tail -n 1)
    [ -z "$ret" ] && ret=$default
    echo $ret
}

install_validate_password_sql_file () {
    local initfile
    initfile="$(mktemp /var/lib/mysql-files/install-validate-password-plugin.XXXXXX.sql)"
    chmod a+r "$initfile"
    echo "SET @@SESSION.SQL_LOG_BIN=0;" > "$initfile"
    echo "INSERT INTO mysql.plugin (name, dl) VALUES ('validate_password', 'validate_password.so');" >> $initfile
    echo $initfile
}

my_which () {
    save_ifs="${IFS-UNSET}"
    IFS=:
    ret=0
    for file
    do
        for dir in $PATH
        do
        if [ -f "$dir/$file" ]
        then
            echo "$dir/$file"
            continue 2
        fi
        done

        ret=1  #signal an error
        break
    done

    if [ "$save_ifs" = UNSET ]
    then
        unset IFS
    else
        IFS="$save_ifs"
    fi
    return $ret  # Success
}

fix_flush_caches() {
    local instance=$1
    flush_caches=$(get_option mysqld_safe flush_caches "0" $instance)
    if [ ${flush_caches} = 1 ]; then
        if [ ! $(my_which sync) ]; then
            echo "sync command not found, required for --flush-caches"
            exit 1
        # Flush file system buffers.
        else
            sync
            ret=$?
            if [ $ret -ne 0 ]; then
                # Huh, the sync() function is always successful...
                echo "sync failed, check if sync is properly installed"
            fi
        fi

        # Locate sysctl, ensure it exists.
        if [ ! $(my_which sysctl) ]; then
            echo "sysctl command not found, required for --flush-caches"
            exit 1
        # Purge page cache, dentries and inodes.
        else
            sysctl -q -w vm.drop_caches=3
            ret=$?
            if [ $ret -ne 0 ]; then
                echo "sysctl failed, check the error message for details"
                exit 1
            fi
        fi
    fi
}

fix_thp_setting() {
    [ -e /etc/sysconfig/mysql ] && . /etc/sysconfig/mysql
    # If no THP_SETTING variable specified in /etc/sysconfig/mysql don't do anything
    if [ ! -z "${THP_SETTING}" ]; then
      # Set whatever option is specified in environment file
      echo "${THP_SETTING}" > /sys/kernel/mm/transparent_hugepage/defrag
      echo "${THP_SETTING}" > /sys/kernel/mm/transparent_hugepage/enabled
    fi
}

install_db () {
    # Note: something different than datadir=/var/lib/mysql requires SELinux policy changes (in enforcing mode)

    # No automatic init wanted
    [ -e /etc/sysconfig/mysql ] && . /etc/sysconfig/mysql
    [ -n "$NO_INIT" ] && exit 0

    local instance=$1
    datadir=$(get_option mysqld datadir "/var/lib/mysql${instance:+-$instance}" $instance)
    log=$(get_option mysqld 'log[_-]error' "/var/log/mysql${instance:+-$instance}.log" $instance)

    # Restore log, dir, perms and SELinux contexts

    if [ ! -d "$datadir" -a ! -h "$datadir" -a "x$(dirname "$datadir")" = "x/var/lib" ]; then
        install -d -m 0751 -omysql -gmysql "$datadir" || exit 1
    fi

    if [ ! -e "$log" -a ! -h "$log" -a x$(dirname "$log") = "x/var/log" ]; then
        case $(basename "$log") in
            mysql*.log) install /dev/null -m0640 -omysql -gmysql "$log" ;;
            *) ;;
        esac
    fi

    if [ -x /usr/sbin/restorecon ]; then
        /usr/sbin/restorecon "$datadir"
        [ -e "$log" ] && /usr/sbin/restorecon "$log"
        for dir in /var/lib/mysql-files /var/lib/mysql-keyring ; do
            if [ -x /usr/sbin/semanage -a -d /var/lib/mysql -a -d $dir ] ; then
                /usr/sbin/semanage fcontext -a -e /var/lib/mysql $dir >/dev/null 2>&1
                /sbin/restorecon -r $dir
            fi
        done
    fi

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

    # Create initial db and install validate_password plugin
    initfile="$(install_validate_password_sql_file)"
    /usr/sbin/mysqld ${instance:+--defaults-group-suffix=@$instance} --initialize \
                     --datadir="$datadir" --user=mysql --init-file="$initfile"
    rm -f "$initfile"

    # Generate certs if needed
    if [ -x /usr/bin/mysql_ssl_rsa_setup -a ! -e "${datadir}/server-key.pem" ] ; then
        /usr/bin/mysql_ssl_rsa_setup --datadir="$datadir" --uid=mysql >/dev/null 2>&1
    fi
    exit 0
}

fix_thp_setting
fix_flush_caches $1
install_db $1

exit 0