#!/bin/bash
# Copyright (C) 2019 Checkmk GmbH - License: GNU General Public License v2
# This file is part of Checkmk (https://checkmk.com). It is subject to the terms and
# conditions defined in the file COPYING, which is part of this source code package.

# Reason for this no-op: shellcheck disable=... before the first command disables the error for the
# entire script.
:

# Disable unused variable error (needed to keep track of version)
# shellcheck disable=SC2034
CMK_VERSION="2.3.0p38"

# gets optional socket as argument
do_query() {
    # workaround because in some cases /root/.my.cnf or /root/.mylogin.cnf are still considered despite the
    # --defaults-file option (SUP-10993)
    HOME=/dev/null

    # we use the sockets full name as instance name:
    INSTANCE_HEADER="[[$2]]"

    # Check if mysqld is running and root password setup
    echo "<<<mysql_ping>>>"
    echo "$INSTANCE_HEADER"
    $MYSQLADMIN --defaults-file="$MK_CONFDIR"/mysql.cfg ${1:+--socket="$1"} ping 2>&1 || return

    echo "<<<mysql>>>"
    echo "$INSTANCE_HEADER"
    $MYSQL --defaults-file="$MK_CONFDIR"/mysql.cfg ${1:+--socket="$1"} -sN \
        -e "show global status ; show global variables ;"

    echo "<<<mysql_capacity>>>"
    echo "$INSTANCE_HEADER"
    $MYSQL --defaults-file="$MK_CONFDIR"/mysql.cfg ${1:+--socket="$1"} -sN \
        -e "SELECT table_schema, sum(data_length + index_length), sum(data_free)
            FROM information_schema.TABLES GROUP BY table_schema"

    MYSQL_VERSION=$($MYSQL --defaults-file="$MK_CONFDIR"/mysql.cfg ${1:+--socket="$1"} -s -e "SELECT VERSION();" | grep -o '^[0-9]\+')
    MYSQL_FULL_VERSION=$($MYSQL --defaults-file="$MK_CONFDIR"/mysql.cfg ${1:+--socket="$1"} -s -e "SELECT VERSION();")

    echo "<<<mysql_replica_slave>>>"
    echo "$INSTANCE_HEADER"

    if echo "$MYSQL_FULL_VERSION" | grep -q "MariaDB"; then
        STATUS_COMMAND="SHOW SLAVE STATUS\G"
    elif [ "$MYSQL_VERSION" -ge 8 ]; then
        STATUS_COMMAND="SHOW REPLICA STATUS\G"
    else
        STATUS_COMMAND="SHOW SLAVE STATUS\G"
    fi
    $MYSQL --defaults-file="$MK_CONFDIR"/mysql.cfg ${1:+--socket="$1"} -s \
        -e "$STATUS_COMMAND"

}

# The following logic exists as well in the windows vbs script mk_mysql
if [ ! -f "${MK_CONFDIR}/mysql.local.cfg" ]; then
    cat <<EOF >"${MK_CONFDIR}/mysql.local.cfg"
# This file is created because some versions of mysqladmin
# issue a warning if there are missing includes.
EOF
fi

if type mariadb-admin &>/dev/null; then
    MYSQL=mariadb
    MYSQLADMIN=mariadb-admin
elif type mysqladmin &>/dev/null; then
    MYSQL=mysql
    MYSQLADMIN=mysqladmin
else
    exit 0
fi

mysql_socket_string=$(grep -F -h socket "$MK_CONFDIR"/mysql{.local,}.cfg | sed -ne 's/.*socket=\([^ ]*\).*/\1/p')
alias_string=$(grep -F -h alias "$MK_CONFDIR"/mysql{.local,}.cfg | sed -ne 's/.*aliases=\([^ ]*\).*/\1/p')

if [ -z "$mysql_socket_string" ]; then
    mysql_socket_string=$(ps -fww -C mysqld | grep "socket" | sed -ne 's/.*socket=\([^ ]*\).*/\1/p')
fi
if [ -z "$mysql_socket_string" ]; then
    do_query "" ""
else
    IFS=" " mapfile -t mysql_sockets <<<"$mysql_socket_string"
    IFS="," read -r -a aliases <<<"$alias_string"

    for i in "${!mysql_sockets[@]}"; do
        socket="${mysql_sockets[i]}"
        alias="${aliases[i]}"
        if [ -z "$alias" ]; then
            do_query "$socket" "$socket"
        else
            do_query "$socket" "$alias"
        fi
    done
fi

# In async execution the cache file would be removed if the plugin exits with non-zero exit code.
# Avoid this from happening, just because the last mysql command failed (due to missing permissions).
exit 0