initial commit

.gitignore

@@ -0,0 +1,15 @@
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+.kotlin
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+.vscode/
+.DS_Store

api/build.gradle

@@ -0,0 +1,3 @@
+dependencies {
+    
+}

api/src/main/java/ru/dragonestia/kubik/ServerEntry.java

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+package ru.dragonestia.kubik;
+
+public record ServerEntry(String id, String address, int port) {}

api/src/main/java/ru/dragonestia/kubik/dto/KubikEventUpdate.java

@@ -0,0 +1,8 @@
+package ru.dragonestia.kubik.dto;
+
+import java.util.HashSet;
+
+public record KubikEventUpdate(HashSet<String> unregistered, HashSet<Entry> registered, boolean initial) {
+
+    public record Entry(String id, String address, int port) {}
+}

api/src/main/java/ru/dragonestia/kubik/dto/ServerData.java

@@ -0,0 +1,5 @@
+package ru.dragonestia.kubik.dto;
+
+public record ServerData(
+        String id
+) {}

api/src/main/java/ru/dragonestia/kubik/dto/ServerRegistrationData.java

@@ -0,0 +1,5 @@
+package ru.dragonestia.kubik.dto;
+
+public record ServerRegistrationData(
+        String id
+) {}

build.gradle

@@ -0,0 +1,41 @@
+subprojects {
+    apply plugin: 'java'
+    apply plugin: 'java-library'
+    apply plugin: 'maven-publish'
+
+    group = 'ru.dragonestia.kubik'
+
+    java {
+        toolchain {
+            languageVersion = JavaLanguageVersion.of(25)
+        }
+    }
+
+    tasks {
+        compileJava {
+            options.encoding = "UTF-8"
+        }
+
+        compileTestJava {
+            options.encoding = "UTF-8"
+        }
+    }
+
+    repositories {
+        mavenCentral()
+        maven { url "https://jitpack.io" }
+    }
+
+    dependencies {
+        compileOnly 'org.projectlombok:lombok:1.18.42'
+        annotationProcessor 'org.projectlombok:lombok:1.18.42'
+
+        testImplementation platform('org.junit:junit-bom:5.10.0')
+        testImplementation 'org.junit.jupiter:junit-jupiter'
+        testImplementation 'org.mockito:mockito-core:5.14.2'
+    }
+
+    test {
+        useJUnitPlatform()
+    }
+}

client/build.gradle

@@ -0,0 +1,28 @@
+plugins {
+    id("com.gradleup.shadow") version "9.3.0"
+}
+
+tasks {
+    shadowJar {
+        manifest {
+            attributes (
+                    "Multi-Release": true,
+                    "Add-Opens": "java.base/java.lang java.base/java.lang.reflect"
+            )
+        }
+
+        mergeServiceFiles()
+    }
+
+    assemble {
+        dependsOn shadowJar, processResources
+    }
+}
+
+dependencies {
+    api project(":api")
+
+    api 'com.squareup.okhttp3:okhttp:5.3.2'
+    api 'com.squareup.okhttp3:okhttp-sse:5.3.2'
+    api 'com.google.code.gson:gson:2.13.2'
+}

client/src/main/java/ru/dragonestia/kubik/client/Kubik.java

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+package ru.dragonestia.kubik.client;
+
+import com.google.gson.Gson;
+import lombok.Getter;
+import okhttp3.HttpUrl;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import ru.dragonestia.kubik.client.proxy.ProxyControl;
+import ru.dragonestia.kubik.client.proxy.ProxyServerRegistry;
+import ru.dragonestia.kubik.client.server.ServerControl;
+import ru.dragonestia.kubik.dto.ServerData;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+
+public class Kubik {
+
+    private final static Gson gson = new Gson();
+
+    @Getter private final String httpUrl;
+    @Getter private final String wsUrl;
+    @Getter private final KubikConfig config;
+    @Getter private final OkHttpClient okHttpClient;
+    private final ScheduledExecutorService executor;
+
+    public Kubik(String httpUrl, String wsUrl) {
+        this(httpUrl, wsUrl, KubikConfig.builder().build());
+    }
+
+    public Kubik(String httpUrl, String wsUrl, KubikConfig config) {
+        this.httpUrl = httpUrl;
+        this.wsUrl = wsUrl;
+        this.config = config;
+        this.executor = Executors.newScheduledThreadPool(config.getThreadPoolSize());
+        this.okHttpClient = new OkHttpClient.Builder().build();
+    }
+
+    public ServerControl initServer(String groupId, int port) {
+        return new ServerControl(this, executor, groupId, port);
+    }
+
+    public ProxyControl initProxy(ProxyServerRegistry registry) {
+        return new ProxyControl(this, executor, registry);
+    }
+
+    public String pickServer(String groupId) {
+        var request = new Request.Builder()
+                .url(HttpUrl.get(getHttpUrl() + "/api/v1/server").newBuilder()
+                        .addQueryParameter("groupId", groupId)
+                        .build())
+                .get()
+                .build();
+
+        try (var response = getOkHttpClient().newCall(request).execute()) {
+            if (!response.isSuccessful()) {
+                throw new RuntimeException("Taken bad response: %s, %s".formatted(response.code(), response.message()));
+            }
+            var data = gson.fromJson(response.body().string(), ServerData.class);
+            return data.id();
+        } catch (Exception ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+
+    static void main() throws InterruptedException {
+        var kubik = new Kubik("http://localhost:8080", "ws://localhost:8080");
+        var serverControl = kubik.initServer("TestServer", 19136);
+        var proxyControl = kubik.initProxy(new ProxyServerRegistry() {
+
+            @Override
+            public void register(String id, String address, int port) {
+                System.out.println("Registering " + id + " to " + address + ":" + port);
+            }
+
+            @Override
+            public void unregister(String id) {
+                System.out.println("Unregistering " + id);
+            }
+        });
+    }
+}

client/src/main/java/ru/dragonestia/kubik/client/KubikConfig.java

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+package ru.dragonestia.kubik.client;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+
+@Getter
+@Builder
+@AllArgsConstructor
+public class KubikConfig {
+
+    @Builder.Default private int threadPoolSize = 1;
+    @Builder.Default private int reconnectDelay = 10;
+    @Builder.Default private int heartbeatDuration = 20;
+}

client/src/main/java/ru/dragonestia/kubik/client/proxy/ProxyControl.java

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+package ru.dragonestia.kubik.client.proxy;
+
+import com.google.gson.Gson;
+import okhttp3.*;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import ru.dragonestia.kubik.ServerEntry;
+import ru.dragonestia.kubik.client.Kubik;
+import ru.dragonestia.kubik.dto.KubikEventUpdate;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Logger;
+
+public class ProxyControl {
+
+    private static final Gson gson = new Gson();
+
+    private final Kubik kubik;
+    private final ScheduledExecutorService executor;
+    private final ProxyServerRegistry registry;
+
+    private final Object lock = new Object();
+    private final Map<String, ServerEntry> knownServers = new ConcurrentHashMap<>();
+    private final Logger logger = Logger.getLogger(ProxyControl.class.getName());
+
+    private WebSocket ws;
+    private ScheduledFuture<?> future;
+
+    public ProxyControl(Kubik kubik, ScheduledExecutorService executor, ProxyServerRegistry registry) {
+        this.kubik = kubik;
+        this.executor = executor;
+        this.registry = registry;
+
+        createConnection();
+    }
+
+    private synchronized void handle(KubikEventUpdate update) {
+        for (var toDelete: update.unregistered()) {
+            var server = knownServers.remove(toDelete);
+            if (server != null) registry.unregister(toDelete);
+        }
+
+        if (update.initial()) {
+            var notAdded = new HashSet<>(knownServers.keySet());
+            for (var toAdd: update.registered()) {
+                var newServer = new ServerEntry(toAdd.id(), toAdd.address(), toAdd.port());
+                var prevServer = knownServers.put(toAdd.id(), newServer);
+                if (!newServer.equals(prevServer)) registry.register(toAdd.id(), toAdd.address(), toAdd.port());
+                notAdded.remove(toAdd.id());
+            }
+            for (var toDelete: notAdded) {
+                knownServers.remove(toDelete);
+                registry.unregister(toDelete);
+            }
+            return;
+        }
+
+        for (var toAdd: update.registered()) {
+            var newServer = new ServerEntry(toAdd.id(), toAdd.address(), toAdd.port());
+            var prevServer = knownServers.put(toAdd.id(), newServer);
+            if (!newServer.equals(prevServer)) registry.register(toAdd.id(), toAdd.address(), toAdd.port());
+        }
+    }
+
+    public void dispose() {
+        synchronized (lock) {
+            if (future != null) {
+                future.cancel(false);
+                future = null;
+            }
+            if (ws != null) {
+                ws.cancel();
+                ws = null;
+            }
+        }
+    }
+
+    private void createConnection() {
+        synchronized (lock) {
+            if (future != null) future = null;
+
+            var request = new Request.Builder()
+                    .url(kubik.getWsUrl() + "/api/v1/server/updates/ws")
+                    .build();
+
+            ws = kubik.getOkHttpClient().newWebSocket(request, new WebSocketListener() {
+
+                @Override
+                public void onOpen(@NotNull WebSocket webSocket, @NotNull Response response) {
+                    //System.out.println("Connected to discovery updates: " + kubik.getWsUrl());
+                }
+
+                @Override
+                public void onMessage(@NotNull WebSocket webSocket, @NotNull String text) {
+                    handle(gson.fromJson(text, KubikEventUpdate.class));
+                }
+
+                @Override
+                public void onFailure(@NotNull WebSocket webSocket, @NotNull Throwable t, @Nullable Response response) {
+                    synchronized (lock) {
+                        ws.cancel();
+                        ws = null;
+
+                        future = executor.schedule(() -> createConnection(), kubik.getConfig().getReconnectDelay(), TimeUnit.SECONDS);
+                    }
+                }
+
+                @Override
+                public void onClosing(@NotNull WebSocket webSocket, int code, @NotNull String reason) {
+                    synchronized (lock) {
+                        ws.cancel();
+                        ws = null;
+
+                        future = executor.schedule(() -> createConnection(), kubik.getConfig().getReconnectDelay(), TimeUnit.SECONDS);
+                    }
+                }
+            });
+        }
+    }
+}

client/src/main/java/ru/dragonestia/kubik/client/proxy/ProxyServerRegistry.java

@@ -0,0 +1,8 @@
+package ru.dragonestia.kubik.client.proxy;
+
+public interface ProxyServerRegistry {
+
+    void register(String id, String address, int port);
+
+    void unregister(String id);
+}

client/src/main/java/ru/dragonestia/kubik/client/server/ServerControl.java

@@ -0,0 +1,99 @@
+package ru.dragonestia.kubik.client.server;
+
+import com.google.gson.Gson;
+import lombok.Getter;
+import okhttp3.HttpUrl;
+import okhttp3.Request;
+import okhttp3.RequestBody;
+import ru.dragonestia.kubik.client.Kubik;
+import ru.dragonestia.kubik.dto.ServerRegistrationData;
+
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+
+public class ServerControl {
+
+    private static final Gson gson = new Gson();
+
+    private final Kubik kubik;
+    private final ScheduledExecutorService executor;
+    @Getter private final String groupId;
+    @Getter private final int port;
+    @Getter private String id;
+    private ScheduledFuture<?> future;
+
+    private final Object lock = new Object();
+
+    public ServerControl(Kubik kubik, ScheduledExecutorService executor, String groupId, int port) {
+        this.kubik = kubik;
+        this.executor = executor;
+        this.groupId = groupId;
+        this.port = port;
+
+        executor.execute(this::doRegisterServer);
+    }
+
+    private void doRegisterServer() {
+        synchronized (lock) {
+            try {
+                registerServer();
+                future = executor.schedule(this::doRegisterServer, kubik.getConfig().getHeartbeatDuration(), TimeUnit.SECONDS);
+            } catch (Exception ex) {
+                future = executor.schedule(this::doRegisterServer, kubik.getConfig().getReconnectDelay(), TimeUnit.SECONDS);
+            }
+        }
+    }
+
+    private void registerServer() {
+        var request = new Request.Builder()
+                .url(HttpUrl.get(kubik.getHttpUrl() + "/api/v1/server").newBuilder()
+                        .addQueryParameter("groupId", groupId)
+                        .addQueryParameter("port", Integer.toString(port))
+                        .build())
+                .post(RequestBody.EMPTY)
+                .build();
+
+        try (var response = kubik.getOkHttpClient().newCall(request).execute()) {
+            if (!response.isSuccessful()) {
+                throw new RuntimeException("Taken bad response: %s, %s".formatted(response.code(), response.message()));
+            }
+
+            var responseObject = gson.fromJson(response.body().string(), ServerRegistrationData.class);
+            id = responseObject.id();
+        } catch (Exception ex) {
+            id = null;
+            throw new RuntimeException(ex);
+        }
+    }
+
+    public void dispose() {
+        synchronized (lock) {
+            if (id == null) return;
+            if (future != null) {
+                future.cancel(false);
+                future = null;
+            }
+            unregisterServer();
+        }
+    }
+
+    private void unregisterServer() {
+        var request = new Request.Builder()
+                .url(HttpUrl.get(kubik.getHttpUrl() + "/api/v1/server").newBuilder()
+                        .addQueryParameter("id", id)
+                        .build())
+                .delete()
+                .build();
+
+        try (var response = kubik.getOkHttpClient().newCall(request).execute()) {
+            if (!response.isSuccessful()) {
+                throw new RuntimeException("Taken bad response: %s, %s".formatted(response.code(), response.message()));
+            }
+        } catch (Exception ex) {
+            throw new RuntimeException(ex);
+        } finally {
+            id = null;
+        }
+    }
+}

client/src/main/java/ru/dragonestia/kubik/client/util/EnvUtil.java

@@ -0,0 +1,13 @@
+package ru.dragonestia.kubik.client.util;
+
+import lombok.experimental.UtilityClass;
+
+import java.util.Optional;
+
+@UtilityClass
+public class EnvUtil {
+
+    public String getString(String key, String defaultValue) {
+        return Optional.ofNullable(System.getenv(key)).orElse(defaultValue);
+    }
+}

discovery/.gitattributes

@@ -0,0 +1,3 @@
+/gradlew text eol=lf
+*.bat text eol=crlf
+*.jar binary

discovery/.gitignore

@@ -0,0 +1,41 @@
+node_modules
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
+
+### Vaadin ###
+src/main/frontend/generated

discovery/Dockerfile

@@ -0,0 +1,9 @@
+FROM amazoncorretto:25.0.1-alpine
+
+RUN mkdir /app
+COPY build/libs/discovery.jar /app
+
+WORKDIR /app
+EXPOSE 8080
+
+ENTRYPOINT exec java -jar discovery.jar

discovery/build.gradle

@@ -0,0 +1,29 @@
+plugins {
+    id 'org.springframework.boot' version '4.0.1'
+    id 'io.spring.dependency-management' version '1.1.7'
+    id 'com.vaadin' version '25.0.2'
+}
+
+ext {
+    set('vaadinVersion', "25.0.2")
+}
+
+dependencies {
+    implementation 'org.springframework.boot:spring-boot-starter-webmvc'
+    implementation 'com.vaadin:vaadin-spring-boot-starter'
+
+    implementation 'commons-codec:commons-codec:1.20.0'
+
+    implementation project(":api")
+
+    developmentOnly 'com.vaadin:vaadin-dev'
+
+    testImplementation 'org.springframework.boot:spring-boot-starter-webmvc-test'
+    testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+}
+
+dependencyManagement {
+    imports {
+        mavenBom "com.vaadin:vaadin-bom:${vaadinVersion}"
+    }
+}

discovery/kubik-discovery.yml

@@ -0,0 +1,41 @@
+apiVersion: apps/v1
+kind: Deployment
+
+metadata:
+  name: kubik-discovery
+  labels:
+    app: kubik-discovery
+
+spec:
+  replicas: 1
+
+  selector:
+    matchLabels:
+      app: kubik-discovery
+
+  template:
+    metadata:
+      labels:
+        app: kubik-discovery
+    spec:
+      containers:
+        - name: kubik-discovery
+          image: kubik-discovery:latest
+          imagePullPolicy: Never
+          ports:
+            - containerPort: 8080
+---
+apiVersion: v1
+kind: Service
+
+metadata:
+  name: kubik-discovery
+
+spec:
+  type: LoadBalancer
+  selector:
+    app: kubik-discovery
+  ports:
+    - port: 8080
+      targetPort: 8080
+      protocol: TCP

discovery/src/main/frontend/index.html

@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<!--
+This file is auto-generated by Vaadin.
+-->
+
+<html>
+<head>
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover" />
+  <style>
+    html, body, #outlet {
+      height: 100%;
+      width: 100%;
+      margin: 0;
+    }
+  </style>
+  <!-- index.ts is included here automatically (either by the dev server or during the build) -->
+</head>
+<body>
+  <!-- This outlet div is where the views are rendered -->
+  <div id="outlet"></div>
+</body>
+</html>

discovery/src/main/java/ru/dragonestia/kubik/discovery/DiscoveryApplication.java

@@ -0,0 +1,14 @@
+package ru.dragonestia.kubik.discovery;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
+@EnableScheduling
+@SpringBootApplication
+public class DiscoveryApplication {
+
+    static void main(String[] args) {
+        SpringApplication.run(DiscoveryApplication.class, args);
+    }
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/component/ServerIdentifierGenerator.java

@@ -0,0 +1,29 @@
+package ru.dragonestia.kubik.discovery.component;
+
+
+import lombok.extern.log4j.Log4j2;
+import org.springframework.stereotype.Component;
+import ru.dragonestia.kubik.discovery.model.ServerIdentifierStrategy;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicInteger;
+
+@Log4j2
+@Component
+public class ServerIdentifierGenerator implements ServerIdentifierStrategy {
+
+    private final Map<Key, String> rememberedServers = new ConcurrentHashMap<>();
+    private final Map<String, AtomicInteger> groupFreeIds = new ConcurrentHashMap<>();
+
+    @Override
+    public synchronized String of(String groupId, String address, int port) {
+        var key = new Key(groupId, address, port);
+        return rememberedServers.computeIfAbsent(key, _ -> {
+            var id = groupFreeIds.computeIfAbsent(groupId, _ -> new AtomicInteger(0));
+            return "%s_%s".formatted(groupId, id.getAndIncrement());
+        });
+    }
+
+    private record Key(String groupId, String address, int port) {}
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/component/UpdateStateNotifier.java

@@ -0,0 +1,94 @@
+package ru.dragonestia.kubik.discovery.component;
+
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+import ru.dragonestia.kubik.discovery.event.ServerRegisterEvent;
+import ru.dragonestia.kubik.discovery.event.ServerUnregisterEvent;
+import ru.dragonestia.kubik.discovery.service.ServerService;
+import ru.dragonestia.kubik.dto.KubikEventUpdate;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Consumer;
+
+@Log4j2
+@RequiredArgsConstructor
+@Component
+public class UpdateStateNotifier {
+
+    private final ServerService serverService;
+    private final Map<UUID, Subscriber> subscribers = new ConcurrentHashMap<>();
+
+    @EventListener
+    void onRegisterServer(ServerRegisterEvent event) {
+        var changes = new KubikEventUpdate(
+                new HashSet<>(),
+                new HashSet<>(List.of(new KubikEventUpdate.Entry(event.id(), event.address(), event.port()))),
+                false
+        );
+        subscribers.values().forEach(subscriber -> subscriber.update(changes));
+    }
+
+    @EventListener
+    void onUnregisterServer(ServerUnregisterEvent event) {
+        var changes = new KubikEventUpdate(
+                new HashSet<>(List.of(event.id())),
+                new HashSet<>(),
+                false
+        );
+        subscribers.values().forEach(subscriber -> subscriber.update(changes));
+    }
+
+    public Subscriber subscribe(Consumer<Object> valueConsumer) {
+        synchronized (UpdateStateNotifier.class) {
+            var subscriber = new Subscriber(this, valueConsumer);
+            subscriber.update(initValues());
+            subscribers.put(subscriber.uuid, subscriber);
+            return subscriber;
+        }
+    }
+
+    public Object initValues() {
+        return new KubikEventUpdate(
+                new HashSet<>(),
+                new HashSet<>(serverService.getAllServers().stream()
+                        .map(server -> new KubikEventUpdate.Entry(server.getId(), server.getAddress(), server.getPort()))
+                        .toList()),
+                true);
+    }
+
+    @RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+    public static class Subscriber {
+
+        private final UUID uuid = UUID.randomUUID();
+
+        private final UpdateStateNotifier manager;
+        private final Consumer<Object> consumer;
+
+        private boolean disposed = false;
+
+        public void update(Object response) {
+            try {
+                consumer.accept(response);
+            } catch (Exception ex) {
+                log.error(ex.getMessage(), ex);
+                dispose();
+            }
+        }
+
+        public void dispose() {
+            synchronized (UpdateStateNotifier.class) {
+                if (disposed) return;
+                disposed = true;
+
+                manager.subscribers.remove(uuid);
+            }
+        }
+    }
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/config/WebSocketConfig.java

@@ -0,0 +1,25 @@
+package ru.dragonestia.kubik.discovery.config;
+
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.socket.config.annotation.EnableWebSocket;
+import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
+import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
+import ru.dragonestia.kubik.discovery.component.UpdateStateNotifier;
+import ru.dragonestia.kubik.discovery.ws.WebSocketHandler;
+import tools.jackson.databind.ObjectMapper;
+
+@EnableWebSocket
+@RequiredArgsConstructor
+@Configuration
+public class WebSocketConfig implements WebSocketConfigurer {
+
+    private final UpdateStateNotifier updateStateNotifier;
+    private final ObjectMapper objectMapper;
+
+    @Override
+    public void registerWebSocketHandlers(@NonNull WebSocketHandlerRegistry registry) {
+        registry.addHandler(new WebSocketHandler(updateStateNotifier, objectMapper), "/api/v1/server/updates/ws");
+    }
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/controller/ServerController.java

@@ -0,0 +1,88 @@
+package ru.dragonestia.kubik.discovery.controller;
+
+import jakarta.servlet.http.HttpServletRequest;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;
+import ru.dragonestia.kubik.discovery.component.UpdateStateNotifier;
+import ru.dragonestia.kubik.discovery.service.ServerService;
+import ru.dragonestia.kubik.dto.ServerData;
+import ru.dragonestia.kubik.dto.ServerRegistrationData;
+
+@Log4j2
+@RequiredArgsConstructor
+@RequestMapping("/api/v1/server")
+@RestController
+public class ServerController {
+
+    private final ServerService serverService;
+    private final UpdateStateNotifier updateStateNotifier;
+
+    @PostMapping
+    ServerRegistrationData registerServer(
+            @RequestParam String groupId,
+            @RequestParam int port,
+            @RequestParam(required = false, defaultValue = "true") boolean canPicked,
+            HttpServletRequest request
+    ) {
+        return registerServer(groupId, request.getRemoteAddr(), port, canPicked);
+    }
+
+    @PostMapping("/direct")
+    ServerRegistrationData registerServer(
+            @RequestParam String groupId,
+            @RequestParam String address,
+            @RequestParam int port,
+            @RequestParam(required = false, defaultValue = "true") boolean canPicked
+    ) {
+        var server = serverService.register(groupId, address, port);
+        server.setCanPicked(canPicked);
+        return new ServerRegistrationData(server.getId());
+    }
+
+    @DeleteMapping
+    void unregisterServer(@RequestParam String id) {
+        serverService.unregister(id);
+    }
+
+    @GetMapping
+    ServerData pickServer(@RequestParam String groupId) {
+        var server = serverService.pick(groupId);
+        if (server == null) return new ServerData(null);
+        return new ServerData(server.getId());
+    }
+
+    @PutMapping("/can-picked")
+    void updateCanPicked(
+            @RequestParam String id,
+            @RequestParam boolean value
+    ) {
+        serverService.find(id).ifPresent(server -> server.setCanPicked(value));
+    }
+
+    @GetMapping("/updates")
+    SseEmitter updateStateStream(HttpServletRequest request) {
+        var emitter = new SseEmitter(-1L);
+        var subscriber = updateStateNotifier.subscribe(response -> {
+            try {
+                emitter.send(response);
+            } catch (Exception ex) {
+                throw new RuntimeException(ex);
+            }
+        });
+        emitter.onTimeout(() -> {
+            log.warn("Timeout SSE connection with {}:{}", request.getRemoteAddr(), request.getRemotePort());
+            subscriber.dispose();
+        });
+        emitter.onError(throwable -> {
+            log.error("Failed send update state for {}:{}. Reason: {}, {}",
+                    request.getRemoteAddr(),
+                    request.getRemotePort(),
+                    throwable.getClass().getSimpleName(),
+                    throwable.getMessage());
+            subscriber.dispose();
+        });
+        return emitter;
+    }
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/event/ServerRegisterEvent.java

@@ -0,0 +1,3 @@
+package ru.dragonestia.kubik.discovery.event;
+
+public record ServerRegisterEvent(String id, String address, int port) {}

discovery/src/main/java/ru/dragonestia/kubik/discovery/event/ServerUnregisterEvent.java

@@ -0,0 +1,3 @@
+package ru.dragonestia.kubik.discovery.event;
+
+public record ServerUnregisterEvent(String id) {}

discovery/src/main/java/ru/dragonestia/kubik/discovery/model/Server.java

@@ -0,0 +1,45 @@
+package ru.dragonestia.kubik.discovery.model;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.apache.commons.codec.binary.Hex;
+
+import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.util.Objects;
+
+@Getter
+public class Server {
+
+    private final String id;
+    private final String groupId;
+    private final String address;
+    private final int port;
+
+    @Setter private boolean canPicked = true;
+    @Setter private Instant lastActivity = Instant.now();
+
+    public Server(ServerIdentifierStrategy identifierStrategy, String groupId, String address, int port) {
+        this.id = identifierStrategy.of(groupId, address, port);
+        this.groupId = groupId;
+        this.address = address;
+        this.port = port;
+    }
+
+    @Override
+    public String toString() {
+        return "Server(id=%s, groupId=%s, address=%s, port=%s, canPicked=%s)".formatted(id, groupId, address, port, canPicked);
+    }
+
+    @Override
+    public int hashCode() {
+        return id.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == null || getClass() != other.getClass()) return false;
+        var server = (Server) other;
+        return Objects.equals(id, server.id);
+    }
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/model/ServerIdentifierStrategy.java

@@ -0,0 +1,6 @@
+package ru.dragonestia.kubik.discovery.model;
+
+public interface ServerIdentifierStrategy {
+
+    String of(String groupId, String address, int port);
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/service/ServerService.java

@@ -0,0 +1,118 @@
+package ru.dragonestia.kubik.discovery.service;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+import ru.dragonestia.kubik.discovery.event.ServerRegisterEvent;
+import ru.dragonestia.kubik.discovery.event.ServerUnregisterEvent;
+import ru.dragonestia.kubik.discovery.model.Server;
+import ru.dragonestia.kubik.discovery.model.ServerIdentifierStrategy;
+
+import java.time.Instant;
+import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+@Log4j2
+@RequiredArgsConstructor
+@Service
+public class ServerService {
+
+    private final ApplicationEventPublisher eventPublisher;
+    private final ServerIdentifierStrategy serverIdentifierStrategy;
+
+    private final Map<String, Server> servers = new ConcurrentHashMap<>();
+    private final Map<String, Set<Server>> groupedServers = new ConcurrentHashMap<>();
+    private final ReadWriteLock lock = new ReentrantReadWriteLock();
+
+    @Value("${kubik.activity-timeout}")
+    private int activityTimeout;
+
+    @Scheduled(timeUnit = TimeUnit.SECONDS, fixedDelay = 1)
+    void gc() {
+        lock.writeLock().lock();
+        try {
+            var now = Instant.now();
+            var timeout = new ArrayList<Server>();
+            for (var server: servers.values()) {
+                if (server.getLastActivity().plusSeconds(activityTimeout).isAfter(now)) continue;
+                timeout.add(server);
+
+                log.warn("Detected inactive server: {}", server);
+            }
+            timeout.forEach(server -> unregister(server.getId()));
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    public Server register(String groupId, String address, int port) {
+        lock.writeLock().lock();
+        try {
+            var server = new Server(serverIdentifierStrategy, groupId, address, port);
+            var lastServer = servers.put(server.getId(), server);
+
+            if (server.equals(lastServer)) return server;
+            log.info("Registering server with groupId={} address={} port={}", groupId, address, port);
+
+            groupedServers.computeIfAbsent(groupId, _ -> new HashSet<>()).add(server);
+            eventPublisher.publishEvent(new ServerRegisterEvent(server.getId(), address, port));
+            return server;
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    public void unregister(String id) {
+        lock.writeLock().lock();
+        try {
+            log.info("Unregistering server {}", id);
+
+            var server = servers.remove(id);
+            if (server != null) {
+                var group = groupedServers.get(server.getGroupId());
+                if (group != null) group.remove(server);
+            }
+
+            eventPublisher.publishEvent(new ServerUnregisterEvent(id));
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    public Server pick(String groupId) {
+        lock.readLock().lock();
+        try {
+            for (var server: groupedServers.get(groupId)) {
+                if (!server.isCanPicked()) continue;
+                return server;
+            }
+            return null;
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+    public Optional<Server> find(String id) {
+        lock.readLock().lock();
+        try {
+            return Optional.ofNullable(servers.get(id));
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+    public Collection<Server> getAllServers() {
+        lock.readLock().lock();
+        try {
+            return servers.values();
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/vaadin/VaadinConfig.java

@@ -0,0 +1,8 @@
+package ru.dragonestia.kubik.discovery.vaadin;
+
+import com.vaadin.flow.component.page.AppShellConfigurator;
+import com.vaadin.flow.component.page.Push;
+import com.vaadin.flow.shared.communication.PushMode;
+
+@Push(PushMode.MANUAL)
+public class VaadinConfig implements AppShellConfigurator {}

discovery/src/main/java/ru/dragonestia/kubik/discovery/vaadin/route/HomeRoute.java

@@ -0,0 +1,83 @@
+package ru.dragonestia.kubik.discovery.vaadin.route;
+
+import com.vaadin.flow.component.Unit;
+import com.vaadin.flow.component.grid.Grid;
+import com.vaadin.flow.component.html.H1;
+import com.vaadin.flow.component.orderedlayout.VerticalLayout;
+import com.vaadin.flow.data.provider.DataProvider;
+import com.vaadin.flow.data.provider.ListDataProvider;
+import com.vaadin.flow.router.PageTitle;
+import com.vaadin.flow.router.Route;
+import ru.dragonestia.kubik.discovery.model.Server;
+import ru.dragonestia.kubik.discovery.service.ServerService;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+@PageTitle("Kubik")
+@Route("")
+public class HomeRoute extends VerticalLayout {
+
+    private static final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
+
+    private final ServerService serverService;
+    private final List<Server> providedServers;
+    private final DataProvider<Server, ?> serverProvider;
+
+    public HomeRoute(ServerService serverService) {
+        this.serverService = serverService;
+        providedServers = new ArrayList<>();
+        serverProvider = new ListDataProvider<>(providedServers);
+
+        add(new H1("Active servers"));
+        add(createGrid());
+
+        update();
+
+        addAttachListener(event -> {
+            var future = scheduler.scheduleWithFixedDelay(
+                    () -> {
+                        var ui = event.getUI();
+                        ui.access(() -> {
+                            update();
+                            ui.push();
+                        });
+                    },
+                    1,
+                    1,
+                    TimeUnit.SECONDS
+            );
+
+            addDetachListener(_ -> future.cancel(false));
+        });
+    }
+
+    private Grid<Server> createGrid() {
+        var grid = new Grid<>(Server.class, false);
+
+        grid.addColumn(Server::getId).setHeader("Id");
+        grid.addColumn(Server::getGroupId).setHeader("Group id");
+        grid.addColumn(Server::getAddress).setHeader("Address");
+        grid.addColumn(Server::getPort).setHeader("Port");
+        grid.addColumn(Server::isCanPicked).setHeader("Can picked");
+        grid.addColumn(server -> {
+            var now = Instant.now();
+            var delta = now.getEpochSecond() - server.getLastActivity().getEpochSecond();
+            return "%ss ago".formatted(delta);
+        }).setHeader("Last activity");
+
+        grid.setHeight(80, Unit.VH);
+        grid.setDataProvider(serverProvider);
+        return grid;
+    }
+
+    private void update() {
+        providedServers.clear();
+        providedServers.addAll(serverService.getAllServers());
+        serverProvider.refreshAll();
+    }
+}

discovery/src/main/java/ru/dragonestia/kubik/discovery/ws/WebSocketHandler.java

@@ -0,0 +1,56 @@
+package ru.dragonestia.kubik.discovery.ws;
+
+import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.web.socket.CloseStatus;
+import org.springframework.web.socket.TextMessage;
+import org.springframework.web.socket.WebSocketSession;
+import org.springframework.web.socket.handler.TextWebSocketHandler;
+import ru.dragonestia.kubik.discovery.component.UpdateStateNotifier;
+import tools.jackson.databind.ObjectMapper;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+@Log4j2
+@RequiredArgsConstructor
+public class WebSocketHandler extends TextWebSocketHandler {
+
+    private final UpdateStateNotifier updateStateNotifier;
+    private final ObjectMapper objectMapper;
+
+    private final Map<String, UpdateStateNotifier.Subscriber> sessions = new ConcurrentHashMap<>();
+
+    @Override
+    public void afterConnectionEstablished(@NonNull WebSocketSession session) {
+        log.info("Opened new ws connection form {}", session.getRemoteAddress());
+
+        var subscriber = updateStateNotifier.subscribe(response -> {
+            try {
+                send(session, objectMapper.writeValueAsString(response));
+            } catch (Exception ex) {
+                log.error(ex.getMessage(), ex);
+            }
+        });
+        sessions.put(session.getId(), subscriber);
+    }
+
+    @Override
+    public void afterConnectionClosed(@NonNull WebSocketSession session, @NonNull CloseStatus status) {
+        log.info("Closed ws connection form {}", session.getRemoteAddress());
+
+        var subscriber = sessions.remove(session.getId());
+        if (subscriber != null) subscriber.dispose();
+    }
+
+    private void send(WebSocketSession session, String message) {
+        log.debug("Sending WS message to {}: {}", session.getRemoteAddress(), message);
+
+        try {
+            session.sendMessage(new TextMessage(message));
+        } catch (Exception ex) {
+            log.error(ex.getMessage(), ex);
+        }
+    }
+}

discovery/src/main/resources/application.yml

@@ -0,0 +1,12 @@
+spring:
+  application:
+    name: discovery
+
+server:
+  port: 8080
+vaadin:
+  allowed-packages:
+    - 'ru/dragonestia/kubik/discovery/vaadin'
+
+kubik:
+  activity-timeout: 30

discovery/src/test/java/ru/dragonestia/kubik/discovery/DiscoveryApplicationTests.java

@@ -0,0 +1,13 @@
+package ru.dragonestia.kubik.discovery;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class DiscoveryApplicationTests {
+
+    @Test
+    void contextLoads() {
+    }
+
+}

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Sat Jan 03 00:43:51 KRAT 2026
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.2.0-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,234 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
+
+APP_NAME="Gradle"
+APP_BASE_NAME=${0##*/}
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+# Collect all arguments for the java command;
+#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
+#     shell script including quotes and variable substitutions, so put them in
+#     double quotes to make sure that they get re-expanded; and
+#   * put everything else in single quotes, so that it's not re-expanded.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,89 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

msb-example-server/Dockerfile

@@ -0,0 +1,9 @@
+FROM amazoncorretto:25.0.1-alpine
+
+RUN mkdir /app
+COPY build/libs/msb-example-server-all.jar /app
+
+WORKDIR /app
+EXPOSE 8080
+
+ENTRYPOINT exec java -jar msb-example-server-all.jar

msb-example-server/build.gradle

@@ -0,0 +1,26 @@
+plugins {
+    id("com.gradleup.shadow") version "9.3.0"
+}
+
+tasks {
+    shadowJar {
+        manifest {
+            attributes (
+                    "Main-Class": "ru.dragonestia.kubik.msb.Main",
+                    "Multi-Release": true,
+                    "Add-Opens": "java.base/java.lang java.base/java.lang.reflect"
+            )
+        }
+
+        mergeServiceFiles()
+    }
+
+    assemble {
+        dependsOn shadowJar, processResources
+    }
+}
+
+dependencies {
+    implementation project(":client")
+    implementation files("./lib/msb.jar")
+}

msb-example-server/msb-example-server.yml

@@ -0,0 +1,80 @@
+apiVersion: apps/v1
+kind: Deployment
+
+metadata:
+  name: msb-example-server
+  labels:
+    app: msb-example-server
+
+spec:
+  replicas: 5
+  selector:
+    matchLabels:
+      app: msb-example-server
+
+  template:
+    metadata:
+      labels:
+        app: msb-example-server
+    spec:
+      containers:
+        - name: msb-example-server
+          image: msb-example-server:latest
+          imagePullPolicy: Never
+          ports:
+            - containerPort: 25565
+          env:
+            - name: KUBIK_DISCOVERY_HTTP_URL
+              value: http://kubik-discovery:8080
+            - name: KUBIK_DISCOVERY_WS_URL
+              value: ws://kubik-discovery:8080
+            - name: KUBIK_GROUP_ID
+              value: test
+---
+apiVersion: apps/v1
+kind: Deployment
+
+metadata:
+  name: lobby
+  labels:
+    app: lobby
+
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: lobby
+
+  template:
+    metadata:
+      labels:
+        app: lobby
+    spec:
+      containers:
+        - name: lobby
+          image: msb-example-server:latest
+          imagePullPolicy: Never
+          ports:
+            - containerPort: 25565
+          env:
+            - name: KUBIK_DISCOVERY_HTTP_URL
+              value: http://kubik-discovery:8080
+            - name: KUBIK_DISCOVERY_WS_URL
+              value: ws://kubik-discovery:8080
+            - name: KUBIK_GROUP_ID
+              value: lobby
+---
+apiVersion: v1
+kind: Service
+
+metadata:
+  name: lobby
+
+spec:
+  type: NodePort
+  selector:
+    app: lobby
+  ports:
+    - port: 25565
+      targetPort: 25565
+      protocol: TCP

msb-example-server/src/main/java/ru/dragonestia/kubik/msb/Main.java

@@ -0,0 +1,54 @@
+package ru.dragonestia.kubik.msb;
+
+import lombok.extern.log4j.Log4j2;
+import net.minestom.server.Auth;
+import net.minestom.server.MinecraftServer;
+import net.minestom.server.entity.GameMode;
+import ru.dragonestia.kubik.client.Kubik;
+import ru.dragonestia.kubik.client.server.ServerControl;
+import ru.dragonestia.kubik.client.util.EnvUtil;
+import ru.dragonestia.kubik.msb.command.TransferCommand;
+import ru.dragonestia.msb.boot.ServerBootstrap;
+import ru.dragonestia.msb.boot.ServerInitializer;
+import ru.dragonestia.msb.module.DebugCommands;
+import ru.dragonestia.msb.module.DefaultFlatWorld;
+
+@Log4j2
+public class Main extends ServerInitializer {
+
+    private Kubik kubik;
+    private ServerControl kubikServerControl;
+
+    static void main() {
+        ServerBootstrap.start("0.0.0.0", 25565, new Main(), new Auth.Velocity("PRk6nlzCuJaE"));
+    }
+
+    @Override
+    public void onLoad() {
+        var kubikHttpUrl = EnvUtil.getString("KUBIK_DISCOVERY_HTTP_URL", "http://localhost:8080");
+        var kubikWsUrl = EnvUtil.getString("KUBIK_DISCOVERY_WS_URL", "ws://localhost:8080");
+
+        log.info("Using kubik urls: {}, {}", kubikHttpUrl, kubikWsUrl);
+
+        kubik = new Kubik(
+                kubikHttpUrl,
+                kubikWsUrl
+        );
+    }
+
+    @Override
+    public void onDefaultModulesLoaded() {
+        DefaultFlatWorld.init(GameMode.CREATIVE);
+        DebugCommands.init();
+    }
+
+    @Override
+    public void onServerStarted() {
+        var kubikGroupId = EnvUtil.getString("KUBIK_GROUP_ID", "none");
+        if (!kubikGroupId.equals("none")) {
+            kubikServerControl = kubik.initServer(kubikGroupId, 25565);
+        }
+
+        MinecraftServer.getCommandManager().register(new TransferCommand(kubik, kubikServerControl));
+    }
+}

msb-example-server/src/main/java/ru/dragonestia/kubik/msb/command/TransferCommand.java

@@ -0,0 +1,55 @@
+package ru.dragonestia.kubik.msb.command;
+
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
+import net.minestom.server.command.CommandSender;
+import net.minestom.server.command.builder.Command;
+import net.minestom.server.command.builder.CommandContext;
+import net.minestom.server.command.builder.arguments.ArgumentString;
+import net.minestom.server.command.builder.arguments.ArgumentType;
+import net.minestom.server.entity.Player;
+import ru.dragonestia.kubik.client.Kubik;
+import ru.dragonestia.kubik.client.server.ServerControl;
+
+public class TransferCommand extends Command {
+
+    private final Kubik kubik;
+    private final ServerControl serverControl;
+
+    private final ArgumentString argServerId = ArgumentType.String("server_Id");
+    private final ArgumentString argGroupId = ArgumentType.String("group_Id");
+
+    public TransferCommand(Kubik kubik, ServerControl serverControl) {
+        super("transfer");
+        this.kubik = kubik;
+        this.serverControl = serverControl;
+
+        addSyntax(this::executeTransferCommandByServerId, ArgumentType.Literal("serverId"), argServerId);
+        addSyntax(this::executeTransferCommandByGroupId, ArgumentType.Literal("groupId"), argGroupId);
+    }
+
+    private void executeTransferCommandByServerId(CommandSender sender, CommandContext ctx) {
+        var player = (Player) sender;
+        var serverId = ctx.get(argServerId);
+
+        transfer(player, serverId);
+    }
+
+    private void executeTransferCommandByGroupId(CommandSender sender, CommandContext ctx) {
+        var player = (Player) sender;
+        var groupId = ctx.get(argGroupId);
+        var serverId = kubik.pickServer(groupId);
+
+        if (serverId == null) {
+            player.sendMessage(Component.text("Cannot find server with groupId=%s".formatted(groupId), NamedTextColor.RED));
+            return;
+        }
+
+        transfer(player, serverId);
+    }
+
+    private void transfer(Player player, String serverId) {
+        player.sendMessage(Component.text("Trying transfer to %s".formatted(serverId), NamedTextColor.YELLOW));
+        player.sendPluginMessage("kubik:transfer", serverId);
+    }
+}

settings.gradle

@@ -0,0 +1,6 @@
+rootProject.name = 'kubik'
+
+include 'api', 'velocity-plugin', 'discovery'
+
+include 'client'
+include 'msb-example-server'

velocity-plugin/build.gradle

@@ -0,0 +1,47 @@
+plugins {
+    id("xyz.jpenilla.run-velocity") version "2.3.1"
+    id("com.gradleup.shadow") version "9.3.0"
+}
+
+group = 'ru.dragonestia.kubik'
+version = '1.0-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+    maven {
+        name = "papermc-repo"
+        url = "https://repo.papermc.io/repository/maven-public/"
+    }
+}
+
+dependencies {
+    compileOnly "com.velocitypowered:velocity-api:3.4.0-SNAPSHOT"
+
+    implementation project(":client")
+
+    annotationProcessor "com.velocitypowered:velocity-api:3.4.0-SNAPSHOT"
+}
+
+tasks {
+    shadowJar {
+        manifest {
+            attributes (
+                    "Multi-Release": true,
+                    "Add-Opens": "java.base/java.lang java.base/java.lang.reflect"
+            )
+        }
+
+        mergeServiceFiles()
+    }
+
+    assemble {
+        dependsOn shadowJar, processResources
+    }
+
+  runVelocity {
+    // Configure the Velocity version for our task.
+    // This is the only required configuration besides applying the plugin.
+    // Your plugin's jar (or shadowJar if present) will be used automatically.
+    velocityVersion("3.4.0-SNAPSHOT")
+  }
+}

velocity-plugin/src/main/java/ru/dragonestia/kubik/plugin/KubikPlugin.java

@@ -0,0 +1,121 @@
+package ru.dragonestia.kubik.plugin;
+
+import com.google.gson.Gson;
+import com.google.inject.Inject;
+import com.velocitypowered.api.event.connection.PluginMessageEvent;
+import com.velocitypowered.api.event.proxy.ProxyInitializeEvent;
+import com.velocitypowered.api.event.Subscribe;
+import com.velocitypowered.api.event.proxy.ProxyShutdownEvent;
+import com.velocitypowered.api.plugin.Plugin;
+import com.velocitypowered.api.proxy.Player;
+import com.velocitypowered.api.proxy.ProxyServer;
+import com.velocitypowered.api.proxy.ServerConnection;
+import com.velocitypowered.api.proxy.messages.MinecraftChannelIdentifier;
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import com.velocitypowered.api.proxy.server.ServerInfo;
+import net.kyori.adventure.text.Component;
+import net.kyori.adventure.text.format.NamedTextColor;
+import org.slf4j.Logger;
+import ru.dragonestia.kubik.client.Kubik;
+import ru.dragonestia.kubik.client.proxy.ProxyControl;
+import ru.dragonestia.kubik.client.proxy.ProxyServerRegistry;
+import ru.dragonestia.kubik.client.util.EnvUtil;
+
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Consumer;
+
+@Plugin(
+    id = "kubik-velocity-plugin",
+    name = "KubikConnector",
+    version = "1.0.0",
+    description = "Kubik connector plugin",
+    authors = { "ScarletRedMan" }
+)
+public class KubikPlugin implements ProxyServerRegistry {
+
+    private final static MinecraftChannelIdentifier KUBIK_TRANSFER_CHANNEL_ID = MinecraftChannelIdentifier.from("kubik:transfer");
+
+    private final ProxyServer proxyServer;
+    private final Logger logger;
+    private final ProxyControl proxyControl;
+
+    private final Gson gson = new Gson();
+    private final Map<String, Consumer<PluginMessageEvent>> pluginChannelHandlers = new ConcurrentHashMap<>();
+    private final Map<String, RegisteredServer> registeredServers = new ConcurrentHashMap<>();
+
+    @Inject
+    public KubikPlugin(ProxyServer proxyServer, Logger logger) {
+        this.proxyServer = proxyServer;
+        this.logger = logger;
+
+        var kubikHttpUrl = EnvUtil.getString("KUBIK_DISCOVERY_HTTP_URL", "http://localhost:8080");
+        var kubikWsUrl = EnvUtil.getString("KUBIK_DISCOVERY_WS_URL", "ws://localhost:8080");
+
+        logger.info("Using kubik urls: {}, {}", kubikHttpUrl, kubikWsUrl);
+
+        var kubik = new Kubik(kubikHttpUrl, kubikWsUrl);
+        proxyControl = kubik.initProxy(this);
+    }
+
+    @Subscribe
+    public void onProxyInitialization(ProxyInitializeEvent event) {
+        registerPluginChannel(KUBIK_TRANSFER_CHANNEL_ID, e -> {
+            e.setResult(PluginMessageEvent.ForwardResult.handled());
+
+            if (!(e.getSource() instanceof ServerConnection backend)) return;
+            var serverId = new String(e.getData(), StandardCharsets.UTF_8);
+            var player = (Player) e.getTarget();
+
+            logger.info("Taken transfer request for player {} to {}", player.getUsername(), serverId);
+            var server = registeredServers.get(serverId);
+            if (server == null) {
+                logger.error("Could not find server with id '{}'", serverId);
+                player.disconnect(Component.text("Сервер '{}' недоступен", NamedTextColor.RED));
+                return;
+            }
+
+            player.createConnectionRequest(server).fireAndForget();
+        });
+    }
+
+    @Subscribe
+    public void onPreShutdown(ProxyShutdownEvent event) {
+        proxyControl.dispose();
+    }
+
+    @Subscribe
+    public void onTakenPluginMessage(PluginMessageEvent event) {
+        var handler = pluginChannelHandlers.get(event.getIdentifier().getId());
+        if (handler != null) handler.accept(event);
+    }
+
+    private void registerPluginChannel(MinecraftChannelIdentifier channelId, Consumer<PluginMessageEvent> handler) {
+        pluginChannelHandlers.put(channelId.getId(), handler);
+        proxyServer.getChannelRegistrar().register(KUBIK_TRANSFER_CHANNEL_ID);
+        logger.info("Registered plugin channel '{}'", channelId.getId());
+    }
+
+    @Override
+    public void register(String id, String address, int port) {
+        var server = registeredServers.computeIfAbsent(id, _ -> proxyServer.createRawRegisteredServer(new ServerInfo(
+                id,
+                InetSocketAddress.createUnresolved(address, port)
+        )));
+
+        logger.info("Registered server '{}'(address={} port={})", id, address, port);
+    }
+
+    @Override
+    public void unregister(String id) {
+        var server = registeredServers.remove(id);
+
+        logger.info("Unregistered server '{}'", id);
+
+        if (server == null) return;
+
+        //TODO
+    }
+}

velocity/.dockerignore

@@ -0,0 +1,5 @@
+Dockerfile
+logs
+lang
+.gitignore
+kubik-proxy.yml

velocity/.gitignore

@@ -0,0 +1,3 @@
+lang
+logs
+plugins/*.jar

velocity/Dockerfile

@@ -0,0 +1,9 @@
+FROM amazoncorretto:25.0.1-alpine
+
+RUN mkdir /app
+COPY . /app
+
+WORKDIR /app
+EXPOSE 25565
+
+ENTRYPOINT exec java -jar proxy.jar

velocity/forwarding.secret

@@ -0,0 +1 @@
+PRk6nlzCuJaE

velocity/kubik-proxy.yml

@@ -0,0 +1,46 @@
+apiVersion: apps/v1
+kind: Deployment
+
+metadata:
+  name: kubik-proxy
+  labels:
+    app: kubik-proxy
+
+spec:
+  replicas: 1
+
+  selector:
+    matchLabels:
+      app: kubik-proxy
+
+  template:
+    metadata:
+      labels:
+        app: kubik-proxy
+    spec:
+      containers:
+        - name: kubik-proxy
+          image: kubik-proxy:latest
+          imagePullPolicy: Never
+          ports:
+            - containerPort: 25565
+          env:
+            - name: KUBIK_DISCOVERY_HTTP_URL
+              value: http://kubik-discovery:8080
+            - name: KUBIK_DISCOVERY_WS_URL
+              value: ws://kubik-discovery:8080
+---
+apiVersion: v1
+kind: Service
+
+metadata:
+  name: kubik-proxy
+
+spec:
+  type: LoadBalancer
+  selector:
+    app: kubik-proxy
+  ports:
+    - port: 25565
+      targetPort: 25565
+      protocol: TCP

velocity/plugins/bStats/config.txt

@@ -0,0 +1,10 @@
+# bStats (https://bStats.org) collects some basic information for plugin authors, like
+# how many people use their plugin and their total player count. It's recommended to keep
+# bStats enabled, but if you're not comfortable with this, you can turn this setting off.
+# There is no performance penalty associated with having metrics enabled, and data sent to
+# bStats is fully anonymous.
+enabled=false
+server-uuid=83212111-4623-4135-ad0e-d444d41e7a82
+log-errors=false
+log-sent-data=false
+log-response-status-text=false

velocity/velocity.toml

@@ -0,0 +1,185 @@
+# Config version. Do not change this
+config-version = "2.7"
+
+# What port should the proxy be bound to? By default, we'll bind to all addresses on port 25565.
+bind = "0.0.0.0:25565"
+
+# What should be the MOTD? This gets displayed when the player adds your server to
+# their server list. Only MiniMessage format is accepted.
+motd = "<#09add3>A Velocity Server"
+
+# What should we display for the maximum number of players? (Velocity does not support a cap
+# on the number of players online.)
+show-max-players = 500
+
+# Should we authenticate players with Mojang? By default, this is on.
+online-mode = true
+
+# Should the proxy enforce the new public key security standard? By default, this is on.
+force-key-authentication = true
+
+# If client's ISP/AS sent from this proxy is different from the one from Mojang's
+# authentication server, the player is kicked. This disallows some VPN and proxy
+# connections but is a weak form of protection.
+prevent-client-proxy-connections = false
+
+# Should we forward IP addresses and other data to backend servers?
+# Available options:
+# - "none":        No forwarding will be done. All players will appear to be connecting
+#                  from the proxy and will have offline-mode UUIDs.
+# - "legacy":      Forward player IPs and UUIDs in a BungeeCord-compatible format. Use this
+#                  if you run servers using Minecraft 1.12 or lower.
+# - "bungeeguard": Forward player IPs and UUIDs in a format supported by the BungeeGuard
+#                  plugin. Use this if you run servers using Minecraft 1.12 or lower, and are
+#                  unable to implement network level firewalling (on a shared host).
+# - "modern":      Forward player IPs and UUIDs as part of the login process using
+#                  Velocity's native forwarding. Only applicable for Minecraft 1.13 or higher.
+player-info-forwarding-mode = "modern"
+
+# If you are using modern or BungeeGuard IP forwarding, configure a file that contains a unique secret here.
+# The file is expected to be UTF-8 encoded and not empty.
+forwarding-secret-file = "forwarding.secret"
+
+# Announce whether or not your server supports Forge. If you run a modded server, we
+# suggest turning this on.
+# 
+# If your network runs one modpack consistently, consider using ping-passthrough = "mods"
+# instead for a nicer display in the server list.
+announce-forge = false
+
+# If enabled (default is false) and the proxy is in online mode, Velocity will kick
+# any existing player who is online if a duplicate connection attempt is made.
+kick-existing-players = false
+
+# Should Velocity pass server list ping requests to a backend server?
+# Available options:
+# - "disabled":    No pass-through will be done. The velocity.toml and server-icon.png
+#                  will determine the initial server list ping response.
+# - "mods":        Passes only the mod list from your backend server into the response.
+#                  The first server in your try list (or forced host) with a mod list will be
+#                  used. If no backend servers can be contacted, Velocity won't display any
+#                  mod information.
+# - "description": Uses the description and mod list from the backend server. The first
+#                  server in the try (or forced host) list that responds is used for the
+#                  description and mod list.
+# - "all":         Uses the backend server's response as the proxy response. The Velocity
+#                  configuration is used if no servers could be contacted.
+ping-passthrough = "DISABLED"
+
+# If enabled (default is false), then a sample of the online players on the proxy will be visible
+# when hovering over the player count in the server list.
+# This doesn't have any effect when ping passthrough is set to either "description" or "all".
+sample-players-in-ping = false
+
+# If not enabled (default is true) player IP addresses will be replaced by <ip address withheld> in logs
+enable-player-address-logging = true
+
+[servers]
+# Configure your servers here. Each key represents the server's name, and the value
+# represents the IP address of the server to connect to.
+lobby = "lobby:25565"
+
+
+# In what order we should try servers when a player logs in or is kicked from a server.
+try = [
+    "lobby"
+]
+
+[forced-hosts]
+# Configure your forced hosts here.
+"lobby.example.com" = [
+    "lobby"
+]
+
+
+[advanced]
+# How large a Minecraft packet has to be before we compress it. Setting this to zero will
+# compress all packets, and setting it to -1 will disable compression entirely.
+compression-threshold = 256
+
+# How much compression should be done (from 0-9). The default is -1, which uses the
+# default level of 6.
+compression-level = -1
+
+# How fast (in milliseconds) are clients allowed to connect after the last connection? By
+# default, this is three seconds. Disable this by setting this to 0.
+login-ratelimit = 3000
+
+# Specify a custom timeout for connection timeouts here. The default is five seconds.
+connection-timeout = 5000
+
+# Specify a read timeout for connections here. The default is 30 seconds.
+read-timeout = 30000
+
+# Enables compatibility with HAProxy's PROXY protocol. If you don't know what this is for, then
+# don't enable it.
+haproxy-protocol = false
+
+# Enables TCP fast open support on the proxy. Requires the proxy to run on Linux.
+tcp-fast-open = false
+
+# Enables BungeeCord plugin messaging channel support on Velocity.
+bungee-plugin-message-channel = true
+
+# Shows ping requests to the proxy from clients.
+show-ping-requests = false
+
+# By default, Velocity will attempt to gracefully handle situations where the user unexpectedly
+# loses connection to the server without an explicit disconnect message by attempting to fall the
+# user back, except in the case of read timeouts. BungeeCord will disconnect the user instead. You
+# can disable this setting to use the BungeeCord behavior.
+failover-on-unexpected-server-disconnect = true
+
+# Declares the proxy commands to 1.13+ clients.
+announce-proxy-commands = true
+
+# Enables the logging of commands
+log-command-executions = false
+
+# Enables logging of player connections when connecting to the proxy, switching servers
+# and disconnecting from the proxy.
+log-player-connections = true
+
+# Allows players transferred from other hosts via the
+# Transfer packet (Minecraft 1.20.5) to be received.
+accepts-transfers = false
+
+# Enables support for SO_REUSEPORT. This may help the proxy scale better on multicore systems
+# with a lot of incoming connections, and provide better CPU utilization than the existing
+# strategy of having a single thread accepting connections and distributing them to worker
+# threads. Disabled by default. Requires Linux or macOS.
+enable-reuse-port = false
+
+# How fast (in milliseconds) are clients allowed to send commands after the last command
+# By default this is 50ms (20 commands per second)
+command-rate-limit = 50
+
+# Should we forward commands to the backend upon being rate limited?
+# This will forward the command to the server instead of processing it on the proxy.
+# Since most server implementations have a rate limit, this will prevent the player
+# from being able to send excessive commands to the server.
+forward-commands-if-rate-limited = true
+
+# How many commands are allowed to be sent after the rate limit is hit before the player is kicked?
+# Setting this to 0 or lower will disable this feature.
+kick-after-rate-limited-commands = 0
+
+# How fast (in milliseconds) are clients allowed to send tab completions after the last tab completion
+tab-complete-rate-limit = 10
+
+# How many tab completions are allowed to be sent after the rate limit is hit before the player is kicked?
+# Setting this to 0 or lower will disable this feature.
+kick-after-rate-limited-tab-completes = 0
+
+[query]
+# Whether to enable responding to GameSpy 4 query responses or not.
+enabled = false
+
+# If query is enabled, on what port should the query protocol listen on?
+port = 25565
+
+# This is the map name that is reported to the query services.
+map = "Velocity"
+
+# Whether plugins should be shown in query response by default or not
+show-plugins = false