cluster: allow empty wgN.conf files as markers to enable the ring

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/cluster/machine_rings.go

@@ -118,8 +118,9 @@ func (m *Machine) tryApplyWireguardConfig(ring int) error {
 	}
 }
 
-func (m *Machine) applyWireguardConfig(ring int, wg *wireguard.Config) error {
+func (m *Machine) applyWireguardConfigNode(ring int, wg *wireguard.Config) error {
 	addr := wg.GetAddress()
+	if !core.IsZero(addr) {
 		zoneID, nodeID, ok := Rings[ring].Decode(addr)
 		if !ok {
 			return fmt.Errorf("%s: invalid address", addr)
@@ -128,11 +129,20 @@ func (m *Machine) applyWireguardConfig(ring int, wg *wireguard.Config) error {
 		if err := m.applyZoneNodeID(zoneID, nodeID); err != nil {
 			return core.Wrap(err, "%s: invalid address", addr)
 		}
+	}
 
 	if err := m.applyWireguardInterfaceConfig(ring, wg.Interface); err != nil {
 		return core.Wrap(err, "interface")
 	}
 
+	return nil
+}
+
+func (m *Machine) applyWireguardConfig(ring int, wg *wireguard.Config) error {
+	if err := m.applyWireguardConfigNode(ring, wg); err != nil {
+		return err
+	}
+
 	for _, peer := range wg.Peer {
 		err := m.applyWireguardPeerConfig(ring, peer)
 		switch {

pkg/wireguard/config.go

@@ -175,11 +175,13 @@ func (p interfaceConfig) Export() (InterfaceConfig, error) {
 		ListenPort: p.ListenPort,
 	}
 
+	if p.PrivateKey != "" {
 		out.PrivateKey, err = PrivateKeyFromBase64(p.PrivateKey)
 		if err != nil {
 			err = core.Wrap(err, "PrivateKey")
 			return InterfaceConfig{}, err
 		}
+	}
 
 	return out, nil
 }