#!/usr/bin/env bash
: <<=cut
=head1 NAME
strelaysrv_ - Plugin to monitor Syncthing relay server

=head1 DESCRIPTION
This plugin gathers metrics from a Syncthing relay server.

This plugin requires the jq utility : https://stedolan.github.io/jq/
This plugin requires the curl utility : https://curl.haxx.se/

Available plugins :
strelaysrv_goroutine #
strelaysrv_num       # 
strelaysrv_proxied   #
strelaysrv_transfer  #
strelaysrv_uptime    #

=head1 CONFIGURATION
To make the plugin connect to the Syncthing relay server one has to use this type of 
configuration
[strelaysrv_*]

env.syncthing_relaysrv_host 127.0.0.1
env.syncthing_relaysrv_port 22070

=head1 AUTHOR
Pierre-Alain TORET <pierre-alain.toret@protonmail.com>

=head1 LICENSE
MIT
=cut

function num {
    case $1 in
       config)
            cat <<'EOM'
graph_title Syncthing relay numbers
graph_category network
graph_vlabel numbers
strelaysrv_num_sessions.label sessions
strelaysrv_num_connections.label connections
strelaysrv_num_pending.label pending session keys
strelaysrv_num_proxies.label proxies
EOM
        exit 0;;
        *)
            NS=$($CURL -s http://$syncthing_relaysrv_host:$syncthing_relaysrv_port/status | $JQ '.numActiveSessions ')
            NC=$($CURL -s http://$syncthing_relaysrv_host:$syncthing_relaysrv_port/status | $JQ '.numConnections ')
            NK=$($CURL -s http://$syncthing_relaysrv_host:$syncthing_relaysrv_port/status | $JQ '.numPendingSessionKeys ')
            NP=$($CURL -s http://$syncthing_relaysrv_host:$syncthing_relaysrv_port/status | $JQ '.numProxies ')
            printf "strelaysrv_num_sessions.value $NS\nstrelaysrv_num_connections.value $NC\nstrelaysrv_num_pending.value $NK\nstrelaysrv_num_proxies.value $NP\n"
    esac
}

function uptime {
    case $1 in
       config)
            cat <<'EOM'
graph_title Syncthing relay uptime
graph_vlabel uptime in seconds
graph_category network
strelaysrv_uptime.label uptime
EOM
        exit 0;;
        *)
            printf "strelaysrv_uptime.value "
            $CURL -s http://$syncthing_relaysrv_host:$syncthing_relaysrv_port/status | $JQ '.uptimeSeconds' 
    esac
}

function goroutine {
    case $1 in
       config)
            cat <<'EOM'
graph_title Syncthing relay go routines
graph_vlabel number of go routines
graph_category network
strelaysrv_goroutine.label routines 
EOM
        exit 0;;
        *)
printf "strelaysrv_goroutine.value "
$CURL -s http://$syncthing_relaysrv_host:$syncthing_relaysrv_port/status | $JQ '.goNumRoutine'
    esac
}

function proxied {
    case $1 in
       config)
            cat <<'EOM'
graph_title Syncthing relay total proxied bits
graph_category network
graph_vlabel bits
graph_args --base 1000
strelaysrv_proxied.label bits
strelaysrv_proxied.cdef strelaysrv_proxied,8,*
EOM
            exit 0;;
	*)
            printf "strelaysrv_proxied.value "
            $CURL -s http://$syncthing_relaysrv_host:$syncthing_relaysrv_port/status | $JQ '.bytesProxied '
    esac
}

function transfer {
    case $1 in
       config)
            cat <<'EOM'
graph_title Syncthing relay transfer rate
graph_category network
graph_vlabel bps
graph_args --base 1000
strelaysrv_transfer.label bps
strelaysrv_transfer.cdef strelaysrv_transfer,1000,*
EOM
            exit 0;;
	*)
            printf "strelaysrv_transfer.value "
            $CURL -s http://$syncthing_relaysrv_host:$syncthing_relaysrv_port/status | $JQ '.kbps10s1m5m15m30m60m[2] '
    esac
}

cd $(dirname $0)

CURL=$(which curl)
JQ=$(which jq) 

case $(basename $0) in 
    strelaysrv_num)
	num $1
	exit 0;;
    strelaysrv_uptime)
	uptime $1
	exit 0;;
    strelaysrv_goroutine)
	goroutine $1
	exit 0;;
    strelaysrv_proxied)
	proxied $1
	exit 0;;
    strelaysrv_transfer)
	transfer $1
	exit 0;;
esac