Use EdgeVPN as a library

EdgeVPN can be used as a library. It is very portable and offers a functional interface.

To join a node in a network from a token, without starting the vpn:

import (
    "github.com/ipfs/go-log"
    "github.com/mudler/edgevpn/pkg/discovery"
    "github.com/mudler/edgevpn/pkg/logger"
    node "github.com/mudler/edgevpn/pkg/node"
)

d := discovery.NewDHT()
m := &discovery.MDNS{}

e, err := node.New(
    node.Logger(logger.New(log.LevelInfo)),
    node.MaxMessageSize(2 << 20),
    node.FromBase64(mDNSEnabled, DHTEnabled, token, d, m),
    // ....
)
if err != nil {
    return err
}

if err := e.Start(ctx); err != nil {
    return err
}

node.FromBase64 decodes the same base64 token the CLI uses (edgevpn -g -b) and wires the discovery services into the node, which is why it takes the *discovery.DHT and *discovery.MDNS values you built above. The two booleans enable mDNS and DHT discovery respectively.

or to start a VPN:

import (
    node "github.com/mudler/edgevpn/pkg/node"
    vpn "github.com/mudler/edgevpn/pkg/vpn"
)

opts, err := vpn.Register(vpnOpts...)
if err != nil {
    return err
}

e, err := node.New(append(o, opts...)...)
if err != nil {
    return err
}

if err := e.Start(ctx); err != nil {
    return err
}

vpn.Register turns a set of vpn.Option values into node options — it registers the VPN as a network service on the node, so there is no separate VPN start call. o is your own []node.Option slice, built the same way as in the first example.

Bringing up the TUN interface needs CAP_NET_ADMIN and access to /dev/net/tun, exactly as the edgevpn binary does.