wgconfd

wgconfd is a configuration manager for WireGuard.

Overview

wgconfd INTERFACE CONFIG starts a process that manages some peers of a WireGuard interface. It adds/overwrites peers it knows about and removes peers once they disappear from its view. It leaves any peers it has never seen intact.

Peers are defined in sources. A source is a JSON file served over a protocol that curl understands.

A "server" peer has a known IP address and talks to other servers directly. A "road warrior" peer communicates with everyone through its base server.

Configuration

The main configuration file is written in toml.

refresh_sec = 1200 # default
min_keepalive = 10 # default
max_keepalive = 0 # default, means "never"

[[source]]
name = "remote1"
url = "https://wg.example.org/peers.json"
ipv4 = [ "172.16.0.0/12", "192.168.5.0/24" ]
ipv6 = [ "2001:db8::/32" ]

[[source]]
name = "remote2"
url = "https://wg.example.com/peers.json"
ipv4 = [ "172.16.0.0/12", "192.168.6.0/24" ]
ipv6 = [ "2001:db8:1234:/48" ]
psk = "/path/to/psk/file"
allow_road_warriors = false

[[source]]
name = "local-user1"
url = "file:///etc/wireguard/example/user1.json"
ipv4 = [ "172.16.5.54/32" ]

[[source]]
name = "local-user2"
url = "file:///etc/wireguard/example/user2.json"
ipv6 = [ "2001:db8::5/128" ]

All IP address ranges from the source URL not entirely contained within the ones configured are discarded - if a source claims 0.0.0.0/0 but the config only allows 10.0.0.0/8, nothing is allowed.

The preshared key is applied to all peers defined in a source. If a single peer is defined in multiple sources, both the endpoint and preshared key are taken from the first source that defines it.

It is possible to override some options for a specific public key, and/or to restrict the source that can define that peer:

[peer."yIOdSFrFQ1WPYS6IUWCsRjzw2Iqq0HMcyVVEXu5z+nM="]
source = "remote2"
endpoint = "[2001:db8::6]:10656"
psk = "QJmzt2PpKx8g98qrOtsNR4tB1bik+fMSabNNXCC5OUU="
keepalive = 20

Alternative configuration

There is an alternative configuration mechanism intended for integration with other software: wgconfd --cmdline INTERFACE ARGS...

The arguments are a sequence of global options and sources:

• min_keepalive SEC
• max_keepalive SEC
• refresh_sec SEC
• source NAME URL [psk PATH] [ipv4 NET,NET,...] [ipv6 NET,NET,...] [required] [allow_road_warriors | deny_road_warriors]
• peer PUBKEY [endpoint IP:PORT] [psk PATH] [keepalive SEC] [source NAME]

Source format

The source describes a list of peers with their associated endpoint address (required), keepalive (optional, defaults to never), and ipv4 and ipv6 ranges (optional, defaults to nothing):

{
	"servers": [{
		"public_key": "hw0U7vI2rhjG9mQ34CUKO6M4dIF9e8ofKj5N6cAPtwY=",
		"endpoint": "198.51.100.66:656",
		"ipv4": [ "10.1.2.0/24" ]
	}, {
		"public_key": "nlFVtJrOwR2sVJji6NQjXnv//GVUK5W9T7ftkSnYPA8=",
		"endpoint": "[2002:cb00:71af::4]:656",
		"ipv4": [ "10.1.3.0/24" ]
	}],
}

Road warriors

wgconfd also supports roaming peers called "road warriors":

{
	...
	"road_warriors": [{
		"public_key": "YJ0Ye/Z/f+kzMu5au8JL/OP+cMs0eRsJPSQ9FZIa7Sk=",
		"base": "hw0U7vI2rhjG9mQ34CUKO6M4dIF9e8ofKj5N6cAPtwY=",
		"ipv4": [ "10.2.5.44/32" ]
	}, ...]
}

A road warrior does not typically run wgconfd. It is instead expected to only talk to its base server peer.

On the base peer, a WireGuard peer is created for the road warrior. On all other peers the allowed IP address ranges of the road warrior are added to its base instead.

A road warrior from one source can use a server from another source, but allowed IPs are always checked against the source that contains the road warrior definition.

The allow_road_warriors option in [[source]] sections can be used to deny being the base of road warriors from certain sources.

Configuration updates

The root object can contain a field "next" with an "update_at" timestamp and another configuration:

{
	"servers": [{
		"public_key": "hw0U7vI2rhjG9mQ34CUKO6M4dIF9e8ofKj5N6cAPtwY=",
		"endpoint": "198.51.100.66:656",
		"ipv4": [ "10.1.2.0/24" ]
	}, {
		"public_key": "nlFVtJrOwR2sVJji6NQjXnv//GVUK5W9T7ftkSnYPA8=",
		"endpoint": "[2002:cb00:71af::4]:656",
		"ipv4": [ "10.1.3.0/24" ]
	}],
	"road_warriors": [{
		"public_key": "YJ0Ye/Z/f+kzMu5au8JL/OP+cMs0eRsJPSQ9FZIa7Sk=",
		"base": "hw0U7vI2rhjG9mQ34CUKO6M4dIF9e8ofKj5N6cAPtwY=",
		"ipv4": [ "10.2.5.44/32" ]
	}],
	"next": {
		"update_at": "2033-05-18T03:33:20Z",
		"servers": [{
			"public_key": "hw0U7vI2rhjG9mQ34CUKO6M4dIF9e8ofKj5N6cAPtwY=",
			"endpoint": "198.51.100.66:656",
			"ipv4": [ "10.1.2.0/24" ]
		}, {
			"public_key": "nlFVtJrOwR2sVJji6NQjXnv//GVUK5W9T7ftkSnYPA8=",
			"endpoint": "[2002:cb00:71af::4]:656",
			"ipv4": [ "10.1.3.0/25" ]
		}, {
			"public_key": "JjSETJ9ACv0sTTEtBE2qp9q4vbeq1i5suwWaJCuncFo=",
			"endpoint": "[2001:db8:ddcc:bbaa::5]:565",
			"ipv4": [ "10.1.3.128/25" ]
		}],
		"road_warriors": [{
			"public_key": "YJ0Ye/Z/f+kzMu5au8JL/OP+cMs0eRsJPSQ9FZIa7Sk=",
			"base": "nlFVtJrOwR2sVJji6NQjXnv//GVUK5W9T7ftkSnYPA8=",
			"ipv4": [ "10.2.5.44/32" ]
		}]
	}
}

All instances of wgconfd using that source will switch to the new configuration at the specified time according to their system clocks. Note that the regular mechanism for updates still applies - to cancel an update, remove the "next" field early enough so that all machines refresh the source before "update_at".

Operating system support

wgconfd should work on all operating systems that provide the wg and curl commands.

systemd-based Linux distributions

Sample unit files are provided in the dist/systemd directory:

• wgconfd@IFNAME.service runs wgconfd on the network interface IFNAME using configuration in /etc/wireguard/IFNAME.toml. The service expects that the interface has already been created and the prviate key has been set.
• wgconfd-state@IFNAME.service should be restarted every time the network interface loses its configuration, for example when wg-quick is restarted.

A Fedora source package is available at https://git.venev.name/hristo/fedora/rust-wgconfd/.

OpenWRT

There is an OpenWRT netifd protocol script in dist/netifd. The global options are set in the interface section in /etc/config/network. Sources and peers are defined in wgconfd_source_IFNAME/wgconfd_peer_IFNAME sections in the same file:

config interface 'wg0'
	option proto 'wgconfd'
	option listen_port '656'
	option private_key 'uAoL9qoAFbAPg46NxIQJ36Zc5gJaYDBleL2iGEa8SEA='
	list ip6addr '2002:db8:1:1/48'
	list ipaddr '10.4.0.1/10'

config wgconfd_source_wg0
	option name 'source1'
	option url 'https://wg.example.org/peers.json'
	list ipv4 '10.5.0.0/16'
	list ip6addr '2002:db8:2:3/48'

config wgconfd_source_wg0
	option name 'source2'
	option url 'https://wg.example.com/peers.json'
	list ipv4 '10.6.0.0/16'

config wgconfd_peer_wg0
	option public_key 'dJyitquxsM3gf8a8yVDko6Se0sKrXi+glUTQN4mPZCo='
	option source 'source2'
	option psk '/etc/wgconfd-psk/example.com-machine1'