#!/usr/bin/env bash

# netdata
# real-time performance and health monitoring, done right!
# (C) 2016 Costa Tsaousis <costa@tsaousis.gr>
# GPL v3+
#
# This plugin requires a special version of fping.
# Get it from https://github.com/ktsaou/fping
# and build it, like this:
#
# cd /usr/src
# git clone https://github.com/ktsaou/fping.git fping-netdata.git
# cd fping-netdata.git
# ./autogen.sh
# ./configure --prefix=/usr/local
# make
# cp src/fping /usr/local/bin/
# chown root:root /usr/local/bin/fping
# chmod 4755 /usr/local/bin/fping
#
# Then, create /etc/netdata/fping.conf
# and set the configuration options given below

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

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

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

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

# 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
NETDATA_CONFIG_DIR="${NETDATA_CONFIG_DIR-/etc/netdata}"

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

# the fping binary to use
# we need one that can output netdata friendly info
fping="$(which fping || command -v fping)"

# a space separated list of hosts to fping
hosts=""

# the time in milliseconds (1 sec = 1000 ms)
# to ping the hosts - by default 2 pings per iteration
ping_every="$((update_every * 1000 / 2))"

# how many retries to make if a host does not respond
retries=1

# -----------------------------------------------------------------------------
# load the configuration file

if [ ! -f "${NETDATA_CONFIG_DIR}/fping.conf" ]
then
	fatal "configuration file '${NETDATA_CONFIG_DIR}/fping.conf' not found - nothing to do."
fi

source "${NETDATA_CONFIG_DIR}/fping.conf"

if [ -z "${hosts}" ]
then
	fatal "no hosts configued in '${NETDATA_CONFIG_DIR}/fping.conf' - nothing to do."
fi

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

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

# execute fping
exec "${fping}" "${options[@]}"

# if we cannot execute fping, stop
fatal "command '${fping} ${options[@]}' failed to be executed."