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+wgconfd
+===
+
+wgconfd is a configuration manager for [WireGuard](https://wireguard.com).
+
+General behavior
+---
+`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.
+
+TODO: Right now `wgconfd` does not persist its state across restarts. Restarting resets all endpoints and does not remove peers that disappeared from its view while it was down.
+
+Configuration
+---
+
+The configuration consists of a set of sources. A source consists of a URL (required), a set of allowed IP address ranges (optional, defaults to nothing), and a preshared key (optional):
+
+```toml
+refresh_sec = 1200 # default
+min_keepalive = 10 # default
+max_keepalive = 0 # default, means "never"
+
+[source.remote1]
+url = "https://wg.example.org/peers.json"
+ipv4 = [ "172.16.0.0/12", "192.168.5.0/24" ]
+ipv6 = [ "2001:db8::/32" ]
+
+[source.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 = "GBRwvlGYEcHqe+ft+px5I9dMAGWAqsghftSDz2PhoM8="
+
+[source.local-user1]
+url = "file:///home/user1/.config/wg-dev.json"
+ipv4 = [ "172.16.5.54/32" ]
+
+[source.local-user2]
+url = "file:///home/user2/.config/wg-dev.json"
+ipv6 = [ "2001:db8::5/128" ]
+```
+
+All IP address ranges from the source URL not entirely contained within the config 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, only the endpoint and preshared key from a single nondeterministic source are considered, but all IP ranges are allowed (TODO: add some per-pubkey filtering).
+
+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):
+
+```json
+{
+	"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":
+
+```json
+{
+	...
+	"road_warriors": [{
+		"public_key": "YJ0Ye/Z/f+kzMu5au8JL/OP+cMs0eRsJPSQ9FZIa7Sk=",
+		"base": "ymTvQHxgEDacZq90T/1dYR4ARvtbBTH4rIHab83WFBY=",
+		"ipv4": [ "10.2.5.44/32" ]
+	}, ...]
+}
+```
+
+A road warrior does not have an endpoint and does not 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 an additional allowed IP address is added for the base.
+
+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.
+
+### Configuration updates
+The root object can contain a field `"next"` with an `"update_at"` timestamp and another configuration:
+
+```json
+{
+	"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": "ymTvQHxgEDacZq90T/1dYR4ARvtbBTH4rIHab83WFBY=",
+		"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": "nlFVtJrOwR2sVJji6NQjXnv//GVUK5W9T7ftkSnYPA8=",
+			"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 same 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"`.