Honor bind address and host in configuration (helidon-io#3105)

Signed-off-by: Tomas Langer <tomas.langer@oracle.com>

Author: tomas-langer

examples/microprofile/multiport/src/main/resources/application.yaml

@@ -19,9 +19,9 @@ server:
   sockets:
     - name: "private"
       port: 8081
-      bind-address: "localhost"
     - name: "admin"
       port: 8082
+      # bind address is optional, if not defined, server host will be used)
       bind-address: "localhost"
 
 # Metrics and health run on admin port

webserver/webserver/src/main/java/io/helidon/webserver/NettyWebServer.java

@@ -17,6 +17,7 @@
 package io.helidon.webserver;
 
 import java.net.BindException;
+import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.util.HashMap;
@@ -240,9 +241,14 @@ public synchronized Single<WebServer> start() {
                     // break because one of the previous channels already failed
                     break;
                 }
+                InetAddress bindAddress = socketConfig.bindAddress();
+                if (bindAddress == null) {
+                    // fall back to the server bind address
+                    bindAddress = configuration.bindAddress();
+                }
 
                 try {
-                    bootstrap.bind(configuration.bindAddress(), port).addListener(channelFuture -> {
+                    bootstrap.bind(bindAddress, port).addListener(channelFuture -> {
                         if (!channelFuture.isSuccess()) {
                             LOGGER.info(() -> "Channel '" + name + "' startup failed with message '"
                                     + channelFuture.cause().getMessage() + "'.");

webserver/webserver/src/main/java/io/helidon/webserver/ServerConfiguration.java

@@ -579,6 +579,8 @@ public Builder config(Config config) {
 
             defaultSocketBuilder.config(config);
 
+            config.get("host").asString().ifPresent(defaultSocketBuilder::host);
+
             DeprecatedConfig.get(config, "worker-count", "workers")
                     .asInt()
                     .ifPresent(this::workersCount);