Add Monitor Graphs to Openwrt

To run the command with the root permission, we must create this script first, which will collect the data and write the data to /tmp folder.

1mkdir /etc/wg

 1#!/bin/sh
 2
 3output=/tmp/wg.collect
 4rm -f $output && touch $output && chmod 666 $output
 5
 6current=$(date +%s)
 7
 8conf="cgCozSFbCG6SvENpITD5n6SF9vWyYO0J6jOuziy3tyU= wg0
 9wFyXEweIGqzB3Keg/bBmxGfBcKpp222/YMyNwvjRgiQ= wg1"
10
11wg show all latest-handshakes | while read line; do
12        device=$(echo $line | awk -F ' ' '{print $1}')
13        peer=$(echo $line | awk -F ' ' '{print $2}')
14        dt=$(echo $line | awk -F ' ' '{print $3}')
15        name=$(echo "$conf" | grep "$peer" | awk -F ' ' '{print $2}')
16
17        if [ "$dt" = "0" ] || [ -z "$name" ]; then
18                continue
19        fi
20
21        diff=$(($current - $dt))
22
23        echo "PUTVAL \"HOSTNAME/exec-wireguard/gauge-last_handshake_$name\" interval=INTERVAL N:$diff" >> $output
24done

The script will write the outputs to the /tmp/wg.collect file. You may want to change the conf settings. It will help us filter which peer we want to monitor and the alias for that peer.

The output is defined here "PUTVAL \"HOSTNAME/exec-wireguard/gauge-last_handshake_$name\" interval=INTERVAL N:$diff". The output format is critical.

• First of all, the HOSTNAME and INTERVAL are placeholders. They will be replaced with the correct value later.
• For the exec-wireguard, exec is the plugin name, the wireguard is the plugin instance name.
• For the gauge-last_handshake_$name, gauge is the metric type. It must be inclued in the /usr/share/collectd/types.db file. You also can use one of the existed type from there. last_handshake_$name is the metric name.

Add the script to the system -> Scheduled Tasks. * * * * * /etc/wg/wg.sh.

Check whether the file /tmp/wg.collect has been created and updated after adding it to the crontab.

Create a file /etc/wg/exec-wg.sh

 1#!/bin/sh
 2
 3HOSTNAME="${COLLECTD_HOSTNAME:-Tux}"
 4INTERVAL="${COLLECTD_INTERVAL:-60}"
 5INTERVAL=$(awk -v i=$INTERVAL 'BEGIN{print int(i)}')
 6
 7input=/tmp/wg.collect
 8
 9while sleep "$INTERVAL"; do
10        cat $input | sed "s/HOSTNAME/$HOSTNAME/g" | sed "s/INTERVAL/$INTERVAL/g"
11done

This script will run and loop forever, read and print the file content. There is nothing special here.

After adding the file to the exec plugin settings UI, run these commands to check if it works.

1# ps |grep exec-wg
2 4001 nobody    1088 SN   /bin/sh /etc/wg/exec-wg.sh
3
4# ls <path-to-rrd-data-directory>/exec-wireguard/
5gauge-last_handshake_wg0.rrd  gauge-last_handshake_wg1.rrd

Create the file /www/luci-static/resources/statistics/rrdtool/definitions/exec.js as bellow.

 1'use strict';
 2'require baseclass';
 3return baseclass.extend({
 4    title: _('Exec'),
 5    rrdargs: function(graph, host, plugin, plugin_instance, dtype) {
 6        // host: Tux
 7        // plugin: exec
 8        // plugin_instance: wireguard
 9        // dtype: null
10        var wireguard_last_handshake_time = {
11            title: "%H: wireguard last handshake time",
12            vlabel: "seconds",
13            alt_autoscale_max: true,
14            data: {
15                types: ["gauge"],
16                options: {
17                    gauge_last_handshake_wg0: {
18                        color: "ff0000",
19                        // noavg: true,
20                        noarea: true,
21                        // overlay: true,
22                        // flip: true,
23                        title: "wg0"
24                    },
25                    gauge_last_handshake_wg1: {
26                        color: "0000ff",
27                        // noavg: true,
28                        noarea: true,
29                        title: "wg1"
30                    }
31                }
32            }
33        };
34        return wireguard_last_handshake_time;
35    }
36});

The important thing in the file

• title: _('Exec'),: define the graph title.
• types: ["gauge"],: define the source data type.
• gauge_last_handshake_wg0 and gauge_last_handshake_wg1: this is optional. I want to rename the metrics name and set the color for the graph. Please notice the _ after the gauge is very important. Don't use - here.