feat: add --listen-address flag

Author: MegaRedHand

config/runtime.exs

@@ -18,6 +18,7 @@ switches = [
   log_file: :string,
   beacon_api: :boolean,
   beacon_api_port: :integer,
+  listen_address: :string,
   discovery_port: :integer,
   boot_nodes: :string,
   keystore_file: :string,
@@ -46,6 +47,7 @@ enable_metrics = Keyword.get(args, :metrics, false)
 metrics_port = Keyword.get(args, :metrics_port, if(enable_metrics, do: 9568, else: nil))
 beacon_api_port = Keyword.get(args, :beacon_api_port, nil)
 enable_beacon_api = Keyword.get(args, :beacon_api, not is_nil(beacon_api_port))
+listen_address = Keyword.get(args, :listen_address)
 discovery_port = Keyword.get(args, :discovery_port, 9000)
 cli_bootnodes = Keyword.get(args, :boot_nodes, "")
 keystore = Keyword.get(args, :keystore_file)
@@ -118,7 +120,10 @@ bootnodes =
   |> Enum.reject(&(&1 == ""))
   |> Enum.concat(bootnodes)
 
-config :lambda_ethereum_consensus, :discovery, port: discovery_port, bootnodes: bootnodes
+config :lambda_ethereum_consensus, :libp2p,
+  port: discovery_port,
+  bootnodes: bootnodes,
+  listen_addr: listen_address
 
 # Engine API
 

lib/lambda_ethereum_consensus/beacon/beacon_node.ex

@@ -79,19 +79,34 @@ defmodule LambdaEthereumConsensus.Beacon.BeaconNode do
   end
 
   defp get_libp2p_args() do
-    config = Application.fetch_env!(:lambda_ethereum_consensus, :discovery)
+    config = Application.fetch_env!(:lambda_ethereum_consensus, :libp2p)
     port = Keyword.fetch!(config, :port)
     bootnodes = Keyword.fetch!(config, :bootnodes)
 
+    listen_addr = Keyword.fetch!(config, :listen_addr) |> parse_listen_addr()
+
     if Enum.empty?(bootnodes) do
       Logger.warning("No bootnodes configured.")
     end
 
     [
-      listen_addr: [],
+      listen_addr: listen_addr,
       enable_discovery: true,
       discovery_addr: "0.0.0.0:#{port}",
       bootnodes: bootnodes
     ]
   end
+
+  defp parse_listen_addr([]), do: []
+
+  defp parse_listen_addr(addr) do
+    case String.split(addr, ":") do
+      [ip, port] ->
+        ["/ip4/#{ip}/tcp/#{port}"]
+
+      _ ->
+        Logger.error("Invalid listen address: #{addr}")
+        System.halt(2)
+    end
+  end
 end

lib/libp2p_port.ex

@@ -48,7 +48,7 @@ defmodule LambdaEthereumConsensus.Libp2pPort do
   ]
 
   @type init_arg ::
-          {:listen_addr, String.t()}
+          {:listen_addr, [String.t()]}
           | {:enable_discovery, boolean()}
           | {:discovery_addr, String.t()}
           | {:bootnodes, [String.t()]}
@@ -67,7 +67,7 @@ defmodule LambdaEthereumConsensus.Libp2pPort do
     * `:opts` - a Keyword list of options to pass onto the GenServer.
       Defaults to `[name: __MODULE__]`.
 
-    * `:listen_addr` - the address to listen on.
+    * `:listen_addr` - the addresses to listen on.
     * `:enable_discovery` - boolean that specifies if the discovery service
       should be started.
     * `:discovery_addr` - the address used by the discovery service.