Peer reconnection address from node announcements

[araspitzu]

Currently the node address information in node_announcement messages is not used when establishing a connection. Peer's addresses are known only when the user initiated the connection providing a destination address, in case of incoming connection the peer's address is blanked out and we can't reconnect. According to the spec the addresses field of node_announcement should contain the network addresses where a peer expects an incoming connection, this PR leverages this information to provide the following enhancements:

• Connect-to a pubkey (no address specified, will use node_announcements)
• Reconnect to peers using their node_announcements address as fallback in case we don't know the address

Fixes #1003

[pm47]

What would be nice is also implement a disconnect API call.

[pm47]

We should also probably make the exponential backoff delay go all the way to 1 hour every reconnect attempt.

[codecov-io]

Codecov Report

Merging #1009 into master will increase coverage by 0.81%.
The diff coverage is 72.72%.

@@            Coverage Diff             @@
##           master    #1009      +/-   ##
==========================================
+ Coverage    80.2%   81.01%   +0.81%     
==========================================
  Files          98       98              
  Lines        7554     8124     +570     
  Branches      296      312      +16     
==========================================
+ Hits         6059     6582     +523     
- Misses       1495     1542      +47

Impacted Files	Coverage Δ
.../src/main/scala/fr/acinq/eclair/db/NetworkDb.scala	100% <ø> (ø)	⬆️
...r-core/src/main/scala/fr/acinq/eclair/Eclair.scala	52.87% <0%> (+0.49%)	⬆️
...cala/fr/acinq/eclair/api/FormParamExtractors.scala	81.81% <100%> (+1.81%)	⬆️
...la/fr/acinq/eclair/db/sqlite/SqliteNetworkDb.scala	98.61% <100%> (+0.08%)	⬆️
...rc/main/scala/fr/acinq/eclair/io/Switchboard.scala	73.84% <25%> (-6.16%)	⬇️
...e/src/main/scala/fr/acinq/eclair/api/Service.scala	68.98% <66.66%> (-0.75%)	⬇️
...-core/src/main/scala/fr/acinq/eclair/io/Peer.scala	75.87% <89.65%> (+0.95%)	⬆️
...scala/fr/acinq/eclair/payment/PaymentRequest.scala	90.45% <0%> (-1.61%)	⬇️
...n/scala/fr/acinq/eclair/channel/ChannelTypes.scala	100% <0%> (ø)	⬆️
...c/main/scala/fr/acinq/eclair/channel/Channel.scala	84.16% <0%> (+1.15%)	⬆️
... and 7 more

[araspitzu]

At commit 3a944e2 all the comments have been addressed, @pm47

[pm47]

Almost there!

[pm47]

How about this refactoring:

diff --git a/eclair-core/src/main/scala/fr/acinq/eclair/io/Peer.scala b/eclair-core/src/main/scala/fr/acinq/eclair/io/Peer.scala
index d7c1f4422..8560a4622 100644
--- a/eclair-core/src/main/scala/fr/acinq/eclair/io/Peer.scala
+++ b/eclair-core/src/main/scala/fr/acinq/eclair/io/Peer.scala
@@ -59,9 +59,9 @@ class Peer(nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: Actor

   when(DISCONNECTED) {
     case Event(Peer.Connect(_, address_opt), d: DisconnectedData) =>
-      address_opt.map(hAndp => new InetSocketAddress(hAndp.getHost, hAndp.getPort)).orElse {
-        getPeerAddressFromNodeAnnouncement()
-      } match {
+      address_opt
+        .map(hostAndPort2InetSocketAddress)
+        .orElse(getPeerAddressFromNodeAnnouncement) match {
         case None =>
           sender ! "no address found"
           stay
@@ -78,7 +78,7 @@ class Peer(nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: Actor
       }

     case Event(Reconnect, d: DisconnectedData) =>
-      d.address_opt.orElse(getPeerAddressFromNodeAnnouncement()) match {
+      d.address_opt.orElse(getPeerAddressFromNodeAnnouncement) match {
         case _ if d.channels.isEmpty => stay // no-op, no more channels with this peer
         case None                    => stay // no-op, we don't know any address to this peer and we won't try reconnecting again
         case Some(address) =>
@@ -518,7 +518,7 @@ class Peer(nodeParams: NodeParams, remoteNodeId: PublicKey, authenticator: Actor
   }

   // TODO gets the first of the list, improve selection?
-  def getPeerAddressFromNodeAnnouncement(): Option[InetSocketAddress] = {
+  def getPeerAddressFromNodeAnnouncement: Option[InetSocketAddress] = {
     nodeParams.db.network.getNode(remoteNodeId).flatMap(_.addresses.headOption.map(_.socketAddress))
   }

@@ -643,4 +643,6 @@ object Peer {
       case _ => true // if there is a filter and message doesn't have a timestamp (e.g. channel_announcement), then we send it
     }
   }
+
+  def hostAndPort2InetSocketAddress(hostAndPort: HostAndPort): InetSocketAddress = new InetSocketAddress(hostAndPort.getHost, hostAndPort.getPort)
 }

NB: for methods without side effect parentheses should be omitted