multi: add unsafedisconnect as a dev config

This commit adds a new dev config `unsafedisconnect` as we sometimes
want to disconnect nodes in our itests.

lncfg/dev.go

@@ -24,6 +24,17 @@ func (d *DevConfig) ChannelReadyWait() time.Duration {
 	return 0
 }
 
+// GetUnsafeDisconnect returns the config value, which is always true for
+// production build.
+//
+// TODO(yy): this is a temporary solution to allow users to reconnect peers to
+// trigger a reestablishiment for the active channels. Once a new dedicated RPC
+// is added to realize that functionality, this function should return false to
+// forbidden disconnecting peers while there are active channels.
+func (d *DevConfig) GetUnsafeDisconnect() bool {
+	return true
+}
+
 // GetReservationTimeout returns the config value for `ReservationTimeout`.
 func (d *DevConfig) GetReservationTimeout() time.Duration {
 	return DefaultReservationTimeout

lncfg/dev_integration.go

@@ -22,6 +22,7 @@ type DevConfig struct {
 	ProcessChannelReadyWait time.Duration `long:"processchannelreadywait" description:"Time to sleep before processing remote node's channel_ready message."`
 	ReservationTimeout      time.Duration `long:"reservationtimeout" description:"The maximum time we keep a pending channel open flow in memory."`
 	ZombieSweeperInterval   time.Duration `long:"zombiesweeperinterval" description:"The time interval at which channel opening flows are evaluated for zombie status."`
+	UnsafeDisconnect        bool          `long:"unsafedisconnect" description:"Allows the rpcserver to intentionally disconnect from peers with open channels."`
 }
 
 // ChannelReadyWait returns the config value `ProcessChannelReadyWait`.
@@ -46,3 +47,8 @@ func (d *DevConfig) GetZombieSweeperInterval() time.Duration {
 
 	return d.ZombieSweeperInterval
 }
+
+// ChannelReadyWait returns the config value `UnsafeDisconnect`.
+func (d *DevConfig) GetUnsafeDisconnect() bool {
+	return d.UnsafeDisconnect
+}

lntest/node/config.go

@@ -206,7 +206,6 @@ func (cfg *BaseNodeConfig) GenArgs() []string {
 	args = append(args, backendArgs...)
 
 	nodeArgs := []string{
-		"--bitcoin.active",
 		"--nobootstrap",
 		"--debuglevel=debug,DISC=trace",
 		"--bitcoin.defaultchanconfs=1",
@@ -241,6 +240,9 @@ func (cfg *BaseNodeConfig) GenArgs() []string {
 		// Speed up the tests for bitcoind backend.
 		"--bitcoind.blockpollinginterval=100ms",
 		"--bitcoind.txpollinginterval=100ms",
+
+		// Allow unsafe disconnect in itest.
+		"--dev.unsafedisconnect",
 	}
 
 	args = append(args, nodeArgs...)

rpcserver.go

@@ -1747,15 +1747,27 @@ func (r *rpcServer) DisconnectPeer(ctx context.Context,
 	// In order to avoid erroneously disconnecting from a peer that we have
 	// an active channel with, if we have any channels active with this
 	// peer, then we'll disallow disconnecting from them.
-	if len(nodeChannels) > 0 {
+	if len(nodeChannels) != 0 {
-		return nil, fmt.Errorf("cannot disconnect from peer(%x), "+
+		// If we are not in a dev environment or the configed dev value
-			"all active channels with the peer need to be closed "+
+		// `unsafedisconnect` is false, we return an error since there
-			"first", pubKeyBytes)
+		// are active channels.
+		if !r.cfg.Dev.GetUnsafeDisconnect() {
+			return nil, fmt.Errorf("cannot disconnect from "+
+				"peer(%x), still has %d active channels",
+				pubKeyBytes, len(nodeChannels))
+		}
+
+		// We are in a dev environment, print a warning log and
+		// disconnect.
+		rpcsLog.Warnf("UnsafeDisconnect mode, disconnecting from "+
+			"peer(%x) while there are %d active channels",
+			pubKeyBytes, len(nodeChannels))
 	}
 
 	// With all initial validation complete, we'll now request that the
 	// server disconnects from the peer.
-	if err := r.server.DisconnectPeer(peerPubKey); err != nil {
+	err = r.server.DisconnectPeer(peerPubKey)
+	if err != nil {
 		return nil, fmt.Errorf("unable to disconnect peer: %v", err)
 	}