Monitoring des sessions BGP de bird via NRPE

#!/bin/sh

# Copyright 2017 alarig <alarig@grifon.fr>
#
# BSD-3-Clause licence
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# 3. Neither the name of the copyright holder nor the names of its contributors
# may be used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

# For debuggin purpose, uncomment the next line and `tail -F` the file.
#exec 2> /tmp/check_bgp.log

usage() {
        printf "Usage:\n"
        printf "check_bgp [-4|-6] -p session\n"
        printf "Must be run with user account able to use birdc/birdc6 or use"
        printf "-s to use birdc with sudo.\n"
}

args=$(getopt 46hsp: $*)

if [ $? -ne 0 ]; then
        usage
        exit 3
fi
set -- $args

while :; do
        case "$1" in
                -h)
                        usage
                        exit 0
                        shift
                        ;;
                -4)
                        VERSION="IPv4"
                        shift
                        ;;
                -6)
                        VERSION="IPv6"
                        shift
                        ;;
                -s)
                        SUDO='sudo'
                        shift
                        ;;
                -p)
                        SESSION="$2"
                        shift; shift
                        ;;
                --)
                        shift; break
                        ;;
        esac
done

# path expansion for birdc and sudo of FreeBSD
PATH="$PATH:/usr/local/sbin/:/usr/local/bin/"

if [ "${VERSION}" = "IPv4" ]; then
        birdc="${SUDO} birdc -r"
elif [ "${VERSION}" = "IPv6" ]; then
        birdc="${SUDO} birdc6 -r"
else
        printf "CRITICAL: Invalid IP version, use -4 for IPv4 and -6 for IPv6\n"
        exit 2
fi

if [ -z ${SESSION} ]; then
        printf "CRITICAL: No session name supplied, use -p \$session.\n"
        exit 2
fi

STATE="$($birdc show protocol ${SESSION} | awk -v session=${SESSION} '$0 ~ session { print $6 }')"

# Session states: https://gitlab.labs.nic.cz/labs/bird/blob/master/proto/bgp/bgp.c#L1465
# Plugin return codes: https://nagios-plugins.org/doc/guidelines.html#AEN78

case ${STATE} in
        Established)
                printf "OK: ${SESSION} is ${STATE}\n"
                exit 0
                ;;
        OpenSent | OpenConfirm)
                printf "WARNING: ${SESSION} is in ${STATE} state\n"
                exit 1
                ;;
        Idle | Connect | Active)
                printf "CRITICAL: ${SESSION} is in ${STATE} state\n"
                exit 2
                ;;
        *)
                printf "Unknown state: ${STATE}\n"
                exit 3
                ;;
esac