.

README.md

@@ -2,7 +2,7 @@ TODO
 - timeout/error handling with reactive
 - unregister server on shutdown
 - infrastructure scripts/glue code w/ daemontools
-- djb's multilogd for logging
+- djb's multilogd for logging(?)
 
 environment
 -----------

core-lib/src/main/java/de/kentoj/scrowlib/servermanager/CrownServerManager.java

@@ -1,7 +1,6 @@
 package de.kentoj.scrowlib.servermanager;
 
 import com.google.common.base.Preconditions;
-import com.google.common.io.Files;
 import de.kentoj.scrowlib.messaging.DocumentRepository;
 import de.kentoj.scrowlib.messaging.NatsRepository;
 import io.nats.client.Connection;
@@ -10,8 +9,6 @@ import org.jetbrains.annotations.NotNull;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-import javax.print.Doc;
-
 public class CrownServerManager implements ServerManager {
 
     private final NatsRepository natsRepo;
@@ -55,19 +52,15 @@ public class CrownServerManager implements ServerManager {
     }
 
     @Override
-    public Mono<@NotNull String> getState(String handle) {
+    public Mono<@NotNull ServerInstance> getInfo(String handle) {
         var payload = DocumentRepository.toBytes(new Document("handle", handle));
-        return natsRepo.request("crown.get-state", payload)
+        return natsRepo.request("crown.get-info", payload)
                 .map(DocumentRepository::fromMessage)
-                .map(doc -> doc.getString("state"));
+                .map(doc -> new ServerInstance(
-    }
+                        handle,
-
+                        doc.getInteger("port"),
-    @Override
+                        doc.getString("state")
-    public Mono<@NotNull Integer> getPort(String handle) {
+                ));
-        var payload = DocumentRepository.toBytes(new Document("handle", handle));
-        return natsRepo.request("crown.get-port", payload)
-                .map(DocumentRepository::fromMessage)
-                .map(doc -> doc.getInteger("port"));
     }
 
     @Override

core-lib/src/main/java/de/kentoj/scrowlib/servermanager/ServerManager.java

@@ -11,19 +11,17 @@ public interface ServerManager {
      */
     Mono<@NotNull ServerInstance> deployServer(String template);
 
-    /**
-     * @return Flux with handles of running servers
-     */
-    Flux<@NotNull ServerInstance> getRunningServers();
-
     /**
      * Attempts a clean shutdown, if that doesn't succeed, kills the server.
      */
     Mono<@NotNull Void> destroyServer(String handle);
 
-    Mono<@NotNull String> getState(String handle);
+    /**
+     * @return Flux with handles of running servers
+     */
+    Flux<@NotNull ServerInstance> getRunningServers();
 
-    Mono<@NotNull Integer> getPort(String handle);
+    Mono<@NotNull ServerInstance> getInfo(String handle);
 
     Mono<@NotNull Void> setState(String handle, String state);
 }

core-velocity/src/main/java/de/kentoj/scrow/corevelocity/ServerRegisterWatchdog.java

@@ -7,6 +7,7 @@ import de.kentoj.scrowlib.messaging.NatsRepository;
 import de.kentoj.scrowlib.servermanager.ServerManager;
 import io.nats.client.Connection;
 import lombok.extern.java.Log;
+import org.jetbrains.annotations.NotNull;
 import reactor.core.publisher.Mono;
 
 import java.net.InetSocketAddress;
@@ -29,15 +30,27 @@ public class ServerRegisterWatchdog {
                 .map(DocumentRepository::fromMessage)
                 .flatMap(doc -> {
                     var state = doc.getString("state");
-                    if (!"UP".equals(state)) return Mono.empty();
-
                     var handle = doc.getString("handle");
-                    return serverManager.getPort(handle)
+                    return handleStateChange(state, handle);
-                            .map(port -> {
-                                log.info("registering " + handle);
-                                return server.registerServer(new ServerInfo(handle, new InetSocketAddress(port)));
-                            });
                 })
                 .subscribe();
     }
+
+    private @NotNull Mono<@NotNull Void> handleStateChange(String state, String handle) {
+        return switch (state) {
+            case "UP" -> serverManager.getInfo(handle)
+                    .doOnNext(instance -> {
+                        log.info("registering " + handle);
+                        server.registerServer(new ServerInfo(handle, new InetSocketAddress(instance.getPort())));
+                    })
+                    .then();
+            case "DOWN" -> serverManager.getInfo(handle)
+                    .doOnNext(instance -> {
+                        log.info("unregistering " + handle);
+                        server.unregisterServer(new ServerInfo(handle, new InetSocketAddress(instance.getPort())));
+                    })
+                    .then();
+            default -> Mono.empty();
+        };
+    }
 }