#!/usr/bin/env bash
# SPDX-License-Identifier: GPL-3.0-or-later

# netdata
# real-time performance and health monitoring, done right!
# (C) 2017 Costa Tsaousis <costa@tsaousis.gr>
# GPL v3+
#
# This plugin requires a latest version of fping.
# You can compile it from source, by running me with option: install

export PATH="${PATH}:/sbin:/usr/sbin:/usr/local/sbin"
export LC_ALL=C

if [ "${1}" = "install" ]
    then
    [ "${UID}" != 0 ] && echo >&2 "Please run me as root. This will install a single binary file: /usr/local/bin/fping." && exit 1

    [ -z "${2}" ] && fping_version="5.0" || fping_version="${2}"

    run() {
        printf >&2 " > "
        printf >&2 "%q " "${@}"
        printf >&2 "\n"
        "${@}" || exit 1
    }

    download() {
        local curl="$(which curl 2>/dev/null || command -v curl 2>/dev/null)"
        [ ! -z "${curl}" ] && run curl -s -L "${1}" && return 0

        local wget="$(which wget 2>/dev/null || command -v wget 2>/dev/null)"
        [ ! -z "${wget}" ] && run wget -q -O - "${1}" && return 0

        echo >&2 "Cannot find 'curl' or 'wget' in this system." && exit 1
    }

    [ ! -d /usr/src ] && run mkdir -p /usr/src
    [ ! -d /usr/local/bin ] && run mkdir -p /usr/local/bin

    run cd /usr/src

    if [ -d "fping-${fping_version}" ]
        then
        run rm -rf "fping-${fping_version}" || exit 1
    fi

    download "https://github.com/schweikert/fping/releases/download/v${fping_version}/fping-${fping_version}.tar.gz" | run tar -zxvpf -
    [ $? -ne 0 ] && exit 1
    run cd "fping-${fping_version}" || exit 1

    run ./configure --prefix=/usr/local
    run make clean
    run make
    if [ -f /usr/local/bin/fping ]
        then
        run mv -f /usr/local/bin/fping /usr/local/bin/fping.old
    fi
    run mv src/fping /usr/local/bin/fping
    run chown root:root /usr/local/bin/fping
    run chmod 4755 /usr/local/bin/fping
    echo >&2
    echo >&2 "All done, you have a compatible fping now at /usr/local/bin/fping."
    echo >&2

    fping="$(which fping  2>/dev/null || command -v fping 2>/dev/null)"
    if [ "${fping}" != "/usr/local/bin/fping" ]
        then
        echo >&2 "You have another fping installed at: ${fping}."
        echo >&2 "Please set:"
        echo >&2
        echo >&2 "  fping=\"/usr/local/bin/fping\""
        echo >&2
        echo >&2 "at /etc/netdata/fping.conf"
        echo >&2
    fi
    exit 0
fi

# -----------------------------------------------------------------------------

PROGRAM_NAME="$(basename "${0}")"

logdate() {
    date "+%Y-%m-%d %H:%M:%S"
}

log() {
    local status="${1}"
    shift

    echo >&2 "$(logdate): ${PROGRAM_NAME}: ${status}: ${*}"

}

warning() {
    log WARNING "${@}"
}

error() {
    log ERROR "${@}"
}

info() {
    log INFO "${@}"
}

fatal() {
    log FATAL "${@}"
	echo "DISABLE"
    exit 1
}

debug=0
debug() {
    [ $debug -eq 1 ] && log DEBUG "${@}"
}

# -----------------------------------------------------------------------------

# store in ${plugin} the name we run under
# this allows us to copy/link fping.plugin under a different name
# to have multiple fping plugins running with different settings
plugin="${PROGRAM_NAME/.plugin/}"


# -----------------------------------------------------------------------------

# the frequency to send info to netdata
# passed by netdata as the first parameter
update_every="${1-1}"

# the netdata configuration directory
# passed by netdata as an environment variable
[ -z "${NETDATA_USER_CONFIG_DIR}"  ] && NETDATA_USER_CONFIG_DIR="@configdir_POST@"
[ -z "${NETDATA_STOCK_CONFIG_DIR}" ] && NETDATA_STOCK_CONFIG_DIR="@libconfigdir_POST@"

# -----------------------------------------------------------------------------
# configuration options
# can be overwritten at /etc/netdata/fping.conf

# the fping binary to use
# we need one that can output netdata friendly info (supporting: -N)
# if you have multiple versions, put here the full filename of the right one
fping="$( which fping 2>/dev/null || command -v fping 2>/dev/null )"

# a space separated list of hosts to fping
# we suggest to put names here and the IPs of these names in /etc/hosts
hosts=""

# the time in milliseconds (1 sec = 1000 ms)
# to ping the hosts - by default 5 pings per host per iteration
ping_every="$((update_every * 1000 / 5))"

# fping options
fping_opts="-R -b 56 -i 1 -r 0 -t 5000"

# -----------------------------------------------------------------------------
# load the configuration files

for CONFIG in "${NETDATA_STOCK_CONFIG_DIR}/${plugin}.conf" "${NETDATA_USER_CONFIG_DIR}/${plugin}.conf"
do
    if [ -f "${CONFIG}" ]
        then
        info "Loading config file '${CONFIG}'..."
        source "${CONFIG}"
        [ $? -ne 0 ] && error "Failed to load config file '${CONFIG}'."
    else
        warning "Cannot find file '${CONFIG}'."
    fi
done

if [ -z "${hosts}" ]
then
	fatal "no hosts configured - nothing to do."
fi

if [ -z "${fping}" ]
then
	fatal "fping command is not found. Please set its full path in '${NETDATA_USER_CONFIG_DIR}/${plugin}.conf'"
fi

if [ ! -x "${fping}" ]
then
	fatal "fping command '${fping}' is not executable - cannot proceed."
fi

if [ ${ping_every} -lt 20 ]
    then
    warning "ping every was set to ${ping_every} but 20 is the minimum for non-root users. Setting it to 20 ms."
    ping_every=20
fi

# the fping options we will use
options=( -N -l -Q ${update_every} -p ${ping_every} ${fping_opts} ${hosts} )

# execute fping
info "starting fping: ${fping} ${options[*]}"
exec "${fping}" "${options[@]}"

# if we cannot execute fping, stop
fatal "command '${fping} ${options[*]}' failed to be executed (returned code $?)."