rename akka-docs dir to docs (#62)

docs/src/test/java/jdocs/discovery/DnsDiscoveryDocTest.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2020-2022 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package jdocs.discovery;
+
+import org.apache.pekko.actor.ActorSystem;
+// #lookup-dns
+import org.apache.pekko.discovery.Discovery;
+import org.apache.pekko.discovery.ServiceDiscovery;
+// #lookup-dns
+import org.apache.pekko.testkit.javadsl.TestKit;
+import docs.discovery.DnsDiscoveryDocSpec;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.scalatestplus.junit.JUnitSuite;
+
+import java.time.Duration;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.TimeUnit;
+
+@SuppressWarnings("unused")
+public class DnsDiscoveryDocTest extends JUnitSuite {
+
+  private static ActorSystem system;
+
+  @BeforeClass
+  public static void setup() {
+    system = ActorSystem.create("DnsDiscoveryDocTest", DnsDiscoveryDocSpec.config());
+  }
+
+  @AfterClass
+  public static void teardown() {
+    TestKit.shutdownActorSystem(system);
+    system = null;
+  }
+
+  @Test
+  public void dnsDiscoveryShouldResolveAkkaIo() throws Exception {
+    try {
+      // #lookup-dns
+
+      ServiceDiscovery discovery = Discovery.get(system).discovery();
+      // ...
+      CompletionStage<ServiceDiscovery.Resolved> result =
+          discovery.lookup("foo", Duration.ofSeconds(3));
+      // #lookup-dns
+
+      result.toCompletableFuture().get(5, TimeUnit.SECONDS);
+    } catch (Exception e) {
+      system.log().warning("Failed lookup akka.io, but ignoring: " + e);
+      // don't fail this test
+    }
+  }
+}