api: add a simple getinfo method (closes ACINQ#98) (ACINQ#100)

* api: add a simple getinfo method returning node id, node alias, port, chain hash and current block height
* api: add short description of getinfo [ci skip]

README.md

@@ -92,6 +92,7 @@ option                       | description               | default value
 
  method       |  params                                       | description
  -------------|-----------------------------------------------|-----------------------------------------------------------
+  getinfo     |                                               | return basic node information (id, chain hash, current block height) 
   connect     | host, port, nodeId                            | connect to another lightning node through a secure connection
   open        | host, port, nodeId, fundingSatoshis, pushMsat | opens a channel with another lightning node
   peers       |                                               | list existing local peers

eclair-core/src/main/scala/fr/acinq/eclair/Setup.scala

@@ -8,7 +8,7 @@ import akka.http.scaladsl.Http
 import akka.stream.ActorMaterializer
 import akka.util.Timeout
 import fr.acinq.bitcoin.{Base58Check, OP_CHECKSIG, OP_DUP, OP_EQUALVERIFY, OP_HASH160, OP_PUSHDATA, Script}
-import fr.acinq.eclair.api.Service
+import fr.acinq.eclair.api.{GetInfoResponse, Service}
 import fr.acinq.eclair.blockchain.rpc.BitcoinJsonRPCClient
 import fr.acinq.eclair.blockchain.zmq.ZMQActor
 import fr.acinq.eclair.blockchain.{ExtendedBitcoinClient, PeerWatcher}
@@ -22,7 +22,7 @@ import org.json4s.JsonAST.JString
 
 import scala.compat.Platform
 import scala.concurrent.duration._
-import scala.concurrent.{Await, ExecutionContext, Promise}
+import scala.concurrent.{Await, ExecutionContext, Future, Promise}
 import scala.util.Try
 
 /**
@@ -108,7 +108,9 @@ class Setup(datadir: File, actorSystemName: String = "default") extends Logging
     override val paymentHandler: ActorRef = _setup.paymentHandler
     override val paymentInitiator: ActorRef = _setup.paymentInitiator
     override val system: ActorSystem = _setup.system
+    override def getInfoResponse: Future[GetInfoResponse] = Future.successful(GetInfoResponse(nodeId = nodeParams.privateKey.publicKey, alias = nodeParams.alias, port = config.getInt("server.port"), chainHash = chainHash, blockHeight = Globals.blockCount.intValue()))
   }
+
   val httpBound = Http().bindAndHandle(api.route, config.getString("api.binding-ip"), config.getInt("api.port"))
 
   Try(Await.result(zmqConnected.future, 5 seconds)).recover { case _ => throw BitcoinZMQConnectionTimeoutException }.get

eclair-core/src/main/scala/fr/acinq/eclair/api/Service.scala

@@ -36,6 +36,7 @@ case class JsonRPCBody(jsonrpc: String = "1.0", id: String = "scala-client", met
 case class Error(code: Int, message: String)
 case class JsonRPCRes(result: AnyRef, error: Option[Error], id: String)
 case class Status(node_id: String)
+case class GetInfoResponse(nodeId: PublicKey, alias: String, port: Int, chainHash: String, blockHeight: Int)
 // @formatter:on
 
 trait Service extends Logging {
@@ -61,6 +62,8 @@ trait Service extends Logging {
 
   def system: ActorSystem
 
+  def getInfoResponse: Future[GetInfoResponse]
+
   val customHeaders = `Access-Control-Allow-Origin`(*) ::
     `Access-Control-Allow-Headers`("Content-Type, Authorization") ::
     `Access-Control-Allow-Methods`(PUT, GET, POST, DELETE, OPTIONS) ::
@@ -79,6 +82,7 @@ trait Service extends Logging {
           entity(as[JsonRPCBody]) {
             req =>
               val f_res: Future[AnyRef] = req match {
+                case JsonRPCBody(_, _, "getinfo", _) => getInfoResponse
                 case JsonRPCBody(_, _, "connect", JString(host) :: JInt(port) :: JString(nodeId) :: Nil) =>
                   (switchboard ? NewConnection(PublicKey(nodeId), new InetSocketAddress(host, port.toInt), None)).mapTo[String]
                 case JsonRPCBody(_, _, "open", JString(host) :: JInt(port) :: JString(nodeId) :: JInt(fundingSatoshi) :: JInt(pushMsat) :: Nil) =>