.

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

@@ -0,0 +1,49 @@
+package de.kentoj.scrow.corevelocity;
+
+import com.google.inject.Inject;
+import com.velocitypowered.api.event.Subscribe;
+import com.velocitypowered.api.event.proxy.ProxyInitializeEvent;
+import com.velocitypowered.api.plugin.Plugin;
+import com.velocitypowered.api.proxy.ProxyServer;
+import de.kentoj.scrowlib.servermanager.CrownServerManager;
+import de.kentoj.scrowlib.servermanager.ServerManager;
+import io.nats.client.Connection;
+import io.nats.client.Nats;
+import io.nats.client.Options;
+import lombok.extern.java.Log;
+
+import java.io.IOException;
+
+@Plugin(
+        id = "corevelocity",
+        name = "CoreVelocity",
+        version = "0.1"
+)
+@Log
+public class CoreVelocity {
+
+    private final ProxyServer server;
+    private final Connection nats;
+    private final ServerManager serverManager;
+    private final ServerRegisterWatchdog registerWatchdog;
+
+    @Inject
+    public CoreVelocity(ProxyServer server) {
+        this.server = server;
+
+        try {
+            var natsHost = System.getenv("HOST_NATS");
+            nats = Nats.connect(Options.builder()
+                    .pedantic()
+                    .server(natsHost)
+                    .build());
+            serverManager = new CrownServerManager(nats);
+            registerWatchdog = new ServerRegisterWatchdog(nats, serverManager, server);
+
+            log.info("listening on " + natsHost + " for server registrations");
+            registerWatchdog.listen();
+        } catch (IOException | InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}

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

@@ -0,0 +1,43 @@
+package de.kentoj.scrow.corevelocity;
+
+import com.velocitypowered.api.proxy.ProxyServer;
+import com.velocitypowered.api.proxy.server.ServerInfo;
+import de.kentoj.scrowlib.messaging.DocumentRepository;
+import de.kentoj.scrowlib.messaging.NatsRepository;
+import de.kentoj.scrowlib.servermanager.ServerManager;
+import io.nats.client.Connection;
+import lombok.extern.java.Log;
+import reactor.core.publisher.Mono;
+
+import java.net.InetSocketAddress;
+
+@Log
+public class ServerRegisterWatchdog {
+
+    private final NatsRepository natsRepo;
+    private final ServerManager serverManager;
+    private final ProxyServer server;
+
+    public ServerRegisterWatchdog(Connection nats, ServerManager serverManager, ProxyServer server) {
+        this.natsRepo = new NatsRepository(nats);
+        this.serverManager = serverManager;
+        this.server = server;
+    }
+
+    public void listen() {
+        natsRepo.subscribe("crown.set-state")
+                .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)
+                            .map(port -> {
+                                log.info("registering " + handle);
+                                return server.registerServer(new ServerInfo(handle, new InetSocketAddress(port)));
+                            });
+                })
+                .subscribe();
+    }
+}