Use actor system as conf container (#1420)

This seems to be recommended practice:
https://doc.akka.io/docs/akka/current/general/actor-systems.html#configuration-container.

As a nice side effect, it allows putting akka-related config in eclair.conf.

Also, reorganize reference.conf/application.conf.

eclair-core/src/main/resources/reference.conf

@@ -179,4 +179,22 @@ eclair {
     executor = "thread-pool-executor"
     type = PinnedDispatcher
   }
+}
+
+akka {
+  io {
+    tcp {
+      # The maximum number of bytes delivered by a `Received` message. Before
+      # more data is read from the network the connection actor will try to
+      # do other work.
+      # The purpose of this setting is to impose a smaller limit than the
+      # configured receive buffer size. When using value 'unlimited' it will
+      # try to read all from the receive buffer.
+      # As per BOLT#8 lightning messages are at most 2 + 16 + 65535 + 16 = 65569bytes
+      # Currently the largest message is update_add_htlc (~1500b).
+      # As a tradeoff to reduce the RAM consumption, in conjunction with tcp pull mode,
+      # the default value is chosen to allow for a decent number of messages to be prefetched.
+      max-received-message-size = 16384b
+    }
+  }
 }

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

@@ -105,10 +105,9 @@ object NodeParams {
    * 3) Optionally provided config
    * 4) Default values in reference.conf
    */
-  def loadConfiguration(datadir: File, overrideDefaults: Config = ConfigFactory.empty()) =
+  def loadConfiguration(datadir: File) =
     ConfigFactory.parseProperties(System.getProperties)
       .withFallback(ConfigFactory.parseFile(new File(datadir, "eclair.conf")))
-      .withFallback(overrideDefaults)
       .withFallback(ConfigFactory.load())
 
   def getSeed(datadir: File): ByteVector = {

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

@@ -65,12 +65,10 @@ import scala.util.{Failure, Success}
  * Created by PM on 25/01/2016.
  *
  * @param datadir          directory where eclair-core will write/read its data.
- * @param overrideDefaults use this parameter to programmatically override the node configuration .
  * @param seed_opt         optional seed, if set eclair will use it instead of generating one and won't create a seed.dat file.
  * @param db               optional databases to use, if not set eclair will create the necessary databases
  */
 class Setup(datadir: File,
-            overrideDefaults: Config = ConfigFactory.empty(),
             seed_opt: Option[ByteVector] = None,
             db: Option[Databases] = None)(implicit system: ActorSystem) extends Logging {
 
@@ -87,8 +85,7 @@ class Setup(datadir: File,
   secureRandom.nextInt()
 
   datadir.mkdirs()
-  val appConfig = NodeParams.loadConfiguration(datadir, overrideDefaults)
-  val config = appConfig.getConfig("eclair")
+  val config = system.settings.config.getConfig("eclair")
   val seed = seed_opt.getOrElse(NodeParams.getSeed(datadir))
   val chain = config.getString("chain")
   val chaindir = new File(datadir, chain)

eclair-core/src/test/scala/fr/acinq/eclair/integration/IntegrationSpec.scala

@@ -16,7 +16,7 @@
 
 package fr.acinq.eclair.integration
 
-import java.io.{File, PrintWriter}
+import java.io.File
 import java.util.{Properties, UUID}
 
 import akka.actor.{ActorRef, ActorSystem}
@@ -102,7 +102,7 @@ class IntegrationSpec extends TestKitBaseClass with BitcoindService with AnyFunS
     "eclair.router.broadcast-interval" -> "2 second",
     "eclair.auto-reconnect" -> false,
     "eclair.to-remote-delay-blocks" -> 144,
-    "eclair.multi-part-payment-expiry" -> "20 seconds").asJava)
+    "eclair.multi-part-payment-expiry" -> "20 seconds").asJava).withFallback(ConfigFactory.load())
 
   implicit val formats = DefaultFormats
 
@@ -135,11 +135,7 @@ class IntegrationSpec extends TestKitBaseClass with BitcoindService with AnyFunS
   def instantiateEclairNode(name: String, config: Config): Unit = {
     val datadir = new File(INTEGRATION_TMP_DIR, s"datadir-eclair-$name")
     datadir.mkdirs()
-    new PrintWriter(new File(datadir, "eclair.conf")) {
-      write(config.root().render())
-      close()
-    }
-    implicit val system = ActorSystem(s"system-$name")
+    implicit val system = ActorSystem(s"system-$name", config)
     val setup = new Setup(datadir)
     val kit = Await.result(setup.bootstrap, 10 seconds)
     nodes = nodes + (name -> kit)

eclair-node-gui/src/main/scala/fr/acinq/eclair/JavafxBoot.scala

@@ -27,15 +27,16 @@ import scala.concurrent.ExecutionContext.Implicits.global
   * Created by PM on 25/01/2016.
   */
 object JavafxBoot extends App with Logging {
-  val datadir = new File(System.getProperty("eclair.datadir", System.getProperty("user.home") + "/.eclair"))
   try {
+    val datadir = new File(System.getProperty("eclair.datadir", System.getProperty("user.home") + "/.eclair"))
+    val config = NodeParams.loadConfiguration(datadir)
     val headless = System.getProperty("eclair.headless") != null
 
     if (headless) {
-      implicit val system = ActorSystem("eclair-node-gui")
+      implicit val system = ActorSystem("eclair-node-gui", config)
       val setup = new Setup(datadir)
       setup.bootstrap.map { kit =>
-        Boot.startApiServiceIfEnabled(setup.config, kit)
+        Boot.startApiServiceIfEnabled(kit)
       }
     } else {
       System.setProperty("javafx.preloader", classOf[FxPreloader].getName)

eclair-node-gui/src/main/scala/fr/acinq/eclair/gui/FxApp.scala

@@ -82,7 +82,8 @@ class FxApp extends Application with Logging {
           mainFXML.setController(controller)
           val mainRoot = mainFXML.load[Parent]
           val datadir = new File(getParameters.getUnnamed.get(0))
-          implicit val system = ActorSystem("eclair-node-gui")
+          val config = NodeParams.loadConfiguration(datadir)
+          implicit val system = ActorSystem("eclair-node-gui", config)
           val setup = new Setup(datadir)
 
           val unitConf = setup.config.getString("gui.unit")
@@ -103,7 +104,7 @@ class FxApp extends Application with Logging {
           pKit.completeWith(setup.bootstrap)
           pKit.future.onComplete {
             case Success(kit) =>
-              Boot.startApiServiceIfEnabled(setup.config, kit)
+              Boot.startApiServiceIfEnabled(kit)
               Platform.runLater(new Runnable {
                 override def run(): Unit = {
                   val scene = new Scene(mainRoot)

eclair-node/src/main/resources/application.conf

@@ -17,40 +17,8 @@ kamon.instrumentation.akka {
 }
 
 akka {
-
   loggers = ["akka.event.slf4j.Slf4jLogger"]
   logger-startup-timeout = 30s
   loglevel = "DEBUG" # akka doc: You can enable DEBUG level for akka.loglevel and control the actual level in the SLF4J backend without any significant overhead, also for production.
   logging-filter = "akka.event.slf4j.Slf4jLoggingFilter"
-
-  io {
-    tcp {
-
-      # The maximum number of bytes delivered by a `Received` message. Before
-      # more data is read from the network the connection actor will try to
-      # do other work.
-      # The purpose of this setting is to impose a smaller limit than the
-      # configured receive buffer size. When using value 'unlimited' it will
-      # try to read all from the receive buffer.
-      # As per BOLT#8 lightning messages are at most 2 + 16 + 65535 + 16 = 65569bytes
-      # Currently the largest message is update_add_htlc (~1500b).
-      # As a tradeoff to reduce the RAM consumption, in conjunction with tcp pull mode,
-      # the default value is chosen to allow for a decent number of messages to be prefetched.
-      max-received-message-size = 16384b
-
-    }
-  }
-
-  # Default maximum content length which should not be exceeded by incoming request entities.
-  # Can be changed at runtime (to a higher or lower value) via the `HttpEntity::withSizeLimit` method.
-  # Note that it is not necessarily a problem to set this to a high value as all stream operations
-  # are always properly backpressured.
-  # Nevertheless you might want to apply some limit in order to prevent a single client from consuming
-  # an excessive amount of server resources.
-  #
-  # Set to `infinite` to completely disable entity length checks. (Even then you can still apply one
-  # programmatically via `withSizeLimit`.)
-  #
-  # We disable the size check, because the batching bitcoin json-rpc client may return very large results
-  http.client.parsing.max-content-length=infinite
 }

eclair-node/src/main/scala/fr/acinq/eclair/Boot.scala

@@ -21,7 +21,6 @@ import java.io.File
 import akka.actor.ActorSystem
 import akka.http.scaladsl.Http
 import akka.stream.{ActorMaterializer, BindFailedException}
-import com.typesafe.config.Config
 import fr.acinq.eclair.api.Service
 import grizzled.slf4j.Logging
 import kamon.Kamon
@@ -33,24 +32,24 @@ import scala.util.{Failure, Success}
   * Created by PM on 25/01/2016.
   */
 object Boot extends App with Logging {
-
-  val datadir = new File(System.getProperty("eclair.datadir", System.getProperty("user.home") + "/.eclair"))
-
   try {
+    val datadir = new File(System.getProperty("eclair.datadir", System.getProperty("user.home") + "/.eclair"))
+    val config = NodeParams.loadConfiguration(datadir)
+
     val plugins = Plugin.loadPlugins(args.map(new File(_)))
     plugins.foreach(plugin => logger.info(s"loaded plugin ${plugin.getClass.getSimpleName}"))
-    implicit val system: ActorSystem = ActorSystem("eclair-node")
+    implicit val system: ActorSystem = ActorSystem("eclair-node", config)
     implicit val ec: ExecutionContext = system.dispatcher
     val setup = new Setup(datadir)
 
-    if (setup.config.getBoolean("enable-kamon")) {
-      Kamon.init(setup.appConfig)
+    if (config.getBoolean("eclair.enable-kamon")) {
+      Kamon.init(config)
     }
 
     plugins.foreach(_.onSetup(setup))
     setup.bootstrap onComplete {
       case Success(kit) =>
-        startApiServiceIfEnabled(setup.config, kit)
+        startApiServiceIfEnabled(kit)
         plugins.foreach(_.onKit(kit))
       case Failure(t) => onError(t)
     }
@@ -61,12 +60,12 @@ object Boot extends App with Logging {
   /**
     * Starts the http APIs service if enabled in the configuration
     *
-    * @param config
     * @param kit
     * @param system
     * @param ec
     */
-  def startApiServiceIfEnabled(config: Config, kit: Kit)(implicit system: ActorSystem, ec: ExecutionContext) = {
+  def startApiServiceIfEnabled(kit: Kit)(implicit system: ActorSystem, ec: ExecutionContext) = {
+    val config = system.settings.config.getConfig("eclair")
     if(config.getBoolean("api.enabled")){
       logger.info(s"json API enabled on port=${config.getInt("api.port")}")
       implicit val materializer = ActorMaterializer()