#!/bin/bash
# Copyright (C) 2019 tribe29 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="2.1.0p18"

# gets optional socket as argument
do_query() {

    # 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 "$INSTANCE_HEADER"
    mysqladmin --defaults-extra-file="$MK_CONFDIR"/mysql.cfg ${1:+--socket="$1"} ping 2>&1 || return

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

    echo "<<<mysql_capacity>>>"
    echo "$INSTANCE_HEADER"
    mysql --defaults-extra-file="$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"

    echo "<<<mysql_slave>>>"
    echo "$INSTANCE_HEADER"
    mysql --defaults-extra-file="$MK_CONFDIR"/mysql.cfg ${1:+--socket="$1"} -s \
        -e "show slave status\G"

}

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 mysqladmin >/dev/null; then
    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
fi