Prometheus WireGuard Exporter

Intro

A Prometheus exporter for WireGuard, written in Rust. This tool exports the wg show all dump results in a format that Prometheus can understand. The exporter is very light on your server resources, both in terms of memory and CPU usage.

Prerequisites

• You need Rust to compile this code. Simply follow the instructions on Rust's website to install the toolchain. If you get weird errors while compiling please try and update your Rust version first (I have developed it on rustc 1.35.0-nightly (8159f389f 2019-04-06)).
• You need WireGuard and the wg CLI in the path. The tool will call wg show all dump and of course will fail if the wg executable is not found. If you want I can add the option of specifying the wg path in the command line, just open an issue for it.

Compilation

To compile the latest master version:

git clone https://github.com/MindFlavor/prometheus_wireguard_exporter.git
cd prometheus_wireguard_exporter
cargo install --path .

If you want the latest release you can simply use:

cargo install prometheus_wireguard_exporter

Usage

Start the binary with -h to get the complete syntax. The parameters are:

Parameter	Mandatory	Valid values	Default	Description
-v	no			Enable verbose mode.
-p	no	any valid port number	9576	Specify the service port. This is the port your Prometheus instance should point to.
-n	no	path to the wireguard configuration file	This flag adds the friendly_name attribute to the exported entries. See Friendly names for more details.

Once started, the tool will listen on the specified port (or the default one, 9576, if not specified) and return a Prometheus valid response at the url /metrics. So to check if the tool is working properly simply browse the http://localhost:9576/metrics (or whichever port you choose).

Friendly Names

Starting from version 1.2 you can instruct the exporter to append a friendly name to the exported entries. This can make the output more understandable than using the public keys. For example this is the standard output:

# HELP wireguard_sent_bytes Bytes sent to the peer
# TYPE wireguard_sent_bytes counter
wireguard_sent_bytes{inteface="wg0", public_key="2S7mA0vEMethCNQrJpJKE81/JmhgtB+tHHLYQhgM6kk=", local_ip="10.70.0.2", local_subnet="32"} 13500788
wireguard_sent_bytes{inteface="wg0", public_key="qnoxQoQI8KKMupLnSSureORV0wMmH7JryZNsmGVISzU=", local_ip="10.70.0.3", local_subnet="32"} 0
wireguard_sent_bytes{inteface="wg0", public_key="L2UoJZN7RmEKsMmqaJgKG0m1S2Zs2wd2ptAf+kb3008=", local_ip="10.70.0.4", local_subnet="32"}  0
wireguard_sent_bytes{inteface="wg0", public_key="MdVOIPKt9K2MPj/sO2NlWQbOnFJ6L/qX80mmhQwsUlA=", local_ip="10.70.0.50", local_subnet="32"} 0
wireguard_sent_bytes{inteface="wg0", public_key="lqYcojJMsIZXMUw1heAFbQHBoKjCEaeo7M1WXDh/KWc=", local_ip="10.70.0.40", local_subnet="32"} 0
wireguard_sent_bytes{inteface="wg0", public_key="928vO9Lf4+Mo84cWu4k1oRyzf0AR7FTGoPKHGoTMSHk=", local_ip="10.70.0.80", local_subnet="32"} 0
wireguard_sent_bytes{inteface="wg0", public_key="wTjv6hS6fKfNK+SzOLo7O6BQjEb6AD1TN9GjwZ08IwA=", local_ip="10.70.0.5", local_subnet="32"} 7975608
# HELP wireguard_received_bytes Bytes received from the peer
# TYPE wireguard_received_bytes counter
wireguard_received_bytes{inteface="wg0", public_key="2S7mA0vEMethCNQrJpJKE81/JmhgtB+tHHLYQhgM6kk=", local_ip="10.70.0.2", local_subnet="32"} 50007604
wireguard_received_bytes{inteface="wg0", public_key="qnoxQoQI8KKMupLnSSureORV0wMmH7JryZNsmGVISzU=", local_ip="10.70.0.3", local_subnet="32"} 0
wireguard_received_bytes{inteface="wg0", public_key="L2UoJZN7RmEKsMmqaJgKG0m1S2Zs2wd2ptAf+kb3008=", local_ip="10.70.0.4", local_subnet="32"}  0
wireguard_received_bytes{inteface="wg0", public_key="MdVOIPKt9K2MPj/sO2NlWQbOnFJ6L/qX80mmhQwsUlA=", local_ip="10.70.0.50", local_subnet="32"} 0
wireguard_received_bytes{inteface="wg0", public_key="lqYcojJMsIZXMUw1heAFbQHBoKjCEaeo7M1WXDh/KWc=", local_ip="10.70.0.40", local_subnet="32"} 0
wireguard_received_bytes{inteface="wg0", public_key="928vO9Lf4+Mo84cWu4k1oRyzf0AR7FTGoPKHGoTMSHk=", local_ip="10.70.0.80", local_subnet="32"} 0
wireguard_received_bytes{inteface="wg0", public_key="wTjv6hS6fKfNK+SzOLo7O6BQjEb6AD1TN9GjwZ08IwA=", local_ip="10.70.0.5", local_subnet="32"} 182505560
# HELP wireguard_latest_handshake_seconds Seconds from the last handshake
# TYPE wireguard_latest_handshake_seconds gauge
wireguard_latest_handshake_seconds{inteface="wg0", public_key="2S7mA0vEMethCNQrJpJKE81/JmhgtB+tHHLYQhgM6kk=", local_ip="10.70.0.2", local_subnet="32"} 50780
wireguard_latest_handshake_seconds{inteface="wg0", public_key="qnoxQoQI8KKMupLnSSureORV0wMmH7JryZNsmGVISzU=", local_ip="10.70.0.3", local_subnet="32"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="L2UoJZN7RmEKsMmqaJgKG0m1S2Zs2wd2ptAf+kb3008=", local_ip="10.70.0.4", local_subnet="32"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="MdVOIPKt9K2MPj/sO2NlWQbOnFJ6L/qX80mmhQwsUlA=", local_ip="10.70.0.50", local_subnet="32"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="lqYcojJMsIZXMUw1heAFbQHBoKjCEaeo7M1WXDh/KWc=", local_ip="10.70.0.40", local_subnet="32"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="928vO9Lf4+Mo84cWu4k1oRyzf0AR7FTGoPKHGoTMSHk=", local_ip="10.70.0.80", local_subnet="32"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="wTjv6hS6fKfNK+SzOLo7O6BQjEb6AD1TN9GjwZ08IwA=", local_ip="10.70.0.5", local_subnet="32"} 63459

And this is the one augmented with friendly names:

# HELP wireguard_sent_bytes Bytes sent to the peer
# TYPE wireguard_sent_bytes counter
wireguard_sent_bytes{inteface="wg0", public_key="2S7mA0vEMethCNQrJpJKE81/JmhgtB+tHHLYQhgM6kk=", local_ip="10.70.0.2", local_subnet="32", friendly_name="OnePlus 6T"} 13500788
wireguard_sent_bytes{inteface="wg0", public_key="qnoxQoQI8KKMupLnSSureORV0wMmH7JryZNsmGVISzU=", local_ip="10.70.0.3", local_subnet="32", friendly_name="varch.local (laptop)"} 0
wireguard_sent_bytes{inteface="wg0", public_key="L2UoJZN7RmEKsMmqaJgKG0m1S2Zs2wd2ptAf+kb3008=", local_ip="10.70.0.4", local_subnet="32", friendly_name="cantarch"} 0
wireguard_sent_bytes{inteface="wg0", public_key="MdVOIPKt9K2MPj/sO2NlWQbOnFJ6L/qX80mmhQwsUlA=", local_ip="10.70.0.50", local_subnet="32", friendly_name="frcognoarch"} 0
wireguard_sent_bytes{inteface="wg0", public_key="lqYcojJMsIZXMUw1heAFbQHBoKjCEaeo7M1WXDh/KWc=", local_ip="10.70.0.40", local_subnet="32", friendly_name="frcognowin10"} 0
wireguard_sent_bytes{inteface="wg0", public_key="928vO9Lf4+Mo84cWu4k1oRyzf0AR7FTGoPKHGoTMSHk=", local_ip="10.70.0.80", local_subnet="32", friendly_name="OnePlus 5T"} 0
wireguard_sent_bytes{inteface="wg0", public_key="wTjv6hS6fKfNK+SzOLo7O6BQjEb6AD1TN9GjwZ08IwA=", local_ip="10.70.0.5", local_subnet="32", friendly_name="folioarch"} 7975608
# HELP wireguard_received_bytes Bytes received from the peer
# TYPE wireguard_received_bytes counter
wireguard_received_bytes{inteface="wg0", public_key="2S7mA0vEMethCNQrJpJKE81/JmhgtB+tHHLYQhgM6kk=", local_ip="10.70.0.2", local_subnet="32", friendly_name="OnePlus 6T"} 50007604
wireguard_received_bytes{inteface="wg0", public_key="qnoxQoQI8KKMupLnSSureORV0wMmH7JryZNsmGVISzU=", local_ip="10.70.0.3", local_subnet="32", friendly_name="varch.local (laptop)"} 0
wireguard_received_bytes{inteface="wg0", public_key="L2UoJZN7RmEKsMmqaJgKG0m1S2Zs2wd2ptAf+kb3008=", local_ip="10.70.0.4", local_subnet="32", friendly_name="cantarch"} 0
wireguard_received_bytes{inteface="wg0", public_key="MdVOIPKt9K2MPj/sO2NlWQbOnFJ6L/qX80mmhQwsUlA=", local_ip="10.70.0.50", local_subnet="32", friendly_name="frcognoarch"} 0
wireguard_received_bytes{inteface="wg0", public_key="lqYcojJMsIZXMUw1heAFbQHBoKjCEaeo7M1WXDh/KWc=", local_ip="10.70.0.40", local_subnet="32", friendly_name="frcognowin10"} 0
wireguard_received_bytes{inteface="wg0", public_key="928vO9Lf4+Mo84cWu4k1oRyzf0AR7FTGoPKHGoTMSHk=", local_ip="10.70.0.80", local_subnet="32", friendly_name="OnePlus 5T"} 0
wireguard_received_bytes{inteface="wg0", public_key="wTjv6hS6fKfNK+SzOLo7O6BQjEb6AD1TN9GjwZ08IwA=", local_ip="10.70.0.5", local_subnet="32", friendly_name="folioarch"} 182505560
# HELP wireguard_latest_handshake_seconds Seconds from the last handshake
# TYPE wireguard_latest_handshake_seconds gauge
wireguard_latest_handshake_seconds{inteface="wg0", public_key="2S7mA0vEMethCNQrJpJKE81/JmhgtB+tHHLYQhgM6kk=", local_ip="10.70.0.2", local_subnet="32", friendly_name="OnePlus 6T"} 50780
wireguard_latest_handshake_seconds{inteface="wg0", public_key="qnoxQoQI8KKMupLnSSureORV0wMmH7JryZNsmGVISzU=", local_ip="10.70.0.3", local_subnet="32", friendly_name="varch.local (laptop)"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="L2UoJZN7RmEKsMmqaJgKG0m1S2Zs2wd2ptAf+kb3008=", local_ip="10.70.0.4", local_subnet="32", friendly_name="cantarch"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="MdVOIPKt9K2MPj/sO2NlWQbOnFJ6L/qX80mmhQwsUlA=", local_ip="10.70.0.50", local_subnet="32", friendly_name="frcognoarch"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="lqYcojJMsIZXMUw1heAFbQHBoKjCEaeo7M1WXDh/KWc=", local_ip="10.70.0.40", local_subnet="32", friendly_name="frcognowin10"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="928vO9Lf4+Mo84cWu4k1oRyzf0AR7FTGoPKHGoTMSHk=", local_ip="10.70.0.80", local_subnet="32", friendly_name="OnePlus 5T"} 1558341167
wireguard_latest_handshake_seconds{inteface="wg0", public_key="wTjv6hS6fKfNK+SzOLo7O6BQjEb6AD1TN9GjwZ08IwA=", local_ip="10.70.0.5", local_subnet="32", friendly_name="folioarch"} 63459

In order for this to work, you need to add comments to your wireguard configuration file (below the [Peer] definition). The comment will be interpreted as friendly_name and added to the entry exported to Prometheus. Note that this is not a standard but, since it's a comment, will not interfere with WireGuard in any way. For example this is how you edit your WireGuard configuration file:

[Peer]
PublicKey = lqYcojJMsIZXMUw1heAFbQHBoKjCEaeo7M1WXDh/KWc=
AllowedIPs = 10.70.0.40/32

[Peer]
PublicKey = 928vO9Lf4+Mo84cWu4k1oRyzf0AR7FTGoPKHGoTMSHk=
AllowedIPs = 10.70.0.80/32

[Peer]
# frcognowin10
PublicKey = lqYcojJMsIZXMUw1heAFbQHBoKjCEaeo7M1WXDh/KWc=
AllowedIPs = 10.70.0.40/32

[Peer]
# OnePlus 5T
PublicKey = 928vO9Lf4+Mo84cWu4k1oRyzf0AR7FTGoPKHGoTMSHk=
AllowedIPs = 10.70.0.80/32

As you can see, all you need to do is to add the friendly name as comment (and enable the flag since this feature is opt-in).

Systemd service file

Now add the exporter to the Prometheus exporters as usual. I recommend to start it as a service. It's necessary to run it as root (if there is a non-root way to call wg show all dump please let me know). My systemd service file is like this one:

[Unit]
Description=Prometheus WireGuard Exporter
Wants=network-online.target
After=network-online.target

[Service]
User=root
Group=root
Type=simple
ExecStart=/usr/local/bin/prometheus_wireguard_exporter -n /etc/wireguard/wg0.conf

[Install]
WantedBy=multi-user.target