Merge pull request #139 from VelocityPowered/reload-command

Reload command

api/src/main/java/com/velocitypowered/api/event/proxy/ProxyReloadEvent.java

@@ -0,0 +1,12 @@
+package com.velocitypowered.api.event.proxy;
+
+/**
+ * This event is fired when the proxy is reloaded by the user using {@code /velocity reload}.
+ */
+public class ProxyReloadEvent {
+
+  @Override
+  public String toString() {
+    return "ProxyReloadEvent";
+  }
+}

build.gradle

@@ -14,7 +14,7 @@ allprojects {
         junitVersion = '5.3.0-M1'
         slf4jVersion = '1.7.25'
         log4jVersion = '2.11.1'
-        nettyVersion = '4.1.30.Final'
+        nettyVersion = '4.1.32.Final'
         guavaVersion = '25.1-jre'
         checkerFrameworkVersion = '2.5.6'
 

proxy/src/main/java/com/velocitypowered/proxy/VelocityServer.java

@@ -7,6 +7,7 @@ import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.velocitypowered.api.event.EventManager;
 import com.velocitypowered.api.event.proxy.ProxyInitializeEvent;
+import com.velocitypowered.api.event.proxy.ProxyReloadEvent;
 import com.velocitypowered.api.event.proxy.ProxyShutdownEvent;
 import com.velocitypowered.api.plugin.PluginContainer;
 import com.velocitypowered.api.plugin.PluginManager;
@@ -40,17 +41,20 @@ import com.velocitypowered.proxy.util.VelocityChannelRegistrar;
 import com.velocitypowered.proxy.util.ratelimit.Ratelimiter;
 import com.velocitypowered.proxy.util.ratelimit.Ratelimiters;
 import io.netty.bootstrap.Bootstrap;
+import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.security.KeyPair;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Optional;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 import net.kyori.text.Component;
 import net.kyori.text.TextComponent;
@@ -70,26 +74,32 @@ public class VelocityServer implements ProxyServer {
       .registerTypeHierarchyAdapter(GameProfile.class, new GameProfileSerializer())
       .create();
 
+  private final ConnectionManager cm;
   private final ProxyOptions options;
-  private @MonotonicNonNull ConnectionManager cm;
   private @MonotonicNonNull VelocityConfiguration configuration;
   private @MonotonicNonNull NettyHttpClient httpClient;
   private @MonotonicNonNull KeyPair serverKeyPair;
-  private @MonotonicNonNull ServerMap servers;
+  private final ServerMap servers;
   private final VelocityCommandManager commandManager = new VelocityCommandManager();
   private final AtomicBoolean shutdownInProgress = new AtomicBoolean(false);
   private boolean shutdown = false;
-  private @MonotonicNonNull VelocityPluginManager pluginManager;
+  private final VelocityPluginManager pluginManager;
 
   private final Map<UUID, ConnectedPlayer> connectionsByUuid = new ConcurrentHashMap<>();
   private final Map<String, ConnectedPlayer> connectionsByName = new ConcurrentHashMap<>();
-  private @MonotonicNonNull VelocityConsole console;
+  private final VelocityConsole console;
   private @MonotonicNonNull Ratelimiter ipAttemptLimiter;
-  private @MonotonicNonNull VelocityEventManager eventManager;
-  private @MonotonicNonNull VelocityScheduler scheduler;
+  private final VelocityEventManager eventManager;
+  private final VelocityScheduler scheduler;
   private final VelocityChannelRegistrar channelRegistrar = new VelocityChannelRegistrar();
 
-  public VelocityServer(final ProxyOptions options) {
+  VelocityServer(final ProxyOptions options) {
+    pluginManager = new VelocityPluginManager(this);
+    eventManager = new VelocityEventManager(pluginManager);
+    scheduler = new VelocityScheduler(pluginManager);
+    console = new VelocityConsole(this);
+    cm = new ConnectionManager(this);
+    servers = new ServerMap(this);
     this.options = options;
   }
 
@@ -138,12 +148,6 @@ public class VelocityServer implements ProxyServer {
     logger.info("Booting up {} {}...", getVersion().getName(), getVersion().getVersion());
 
     serverKeyPair = EncryptionUtils.createRsaKeyPair(1024);
-    pluginManager = new VelocityPluginManager(this);
-    eventManager = new VelocityEventManager(pluginManager);
-    scheduler = new VelocityScheduler(pluginManager);
-    console = new VelocityConsole(this);
-    cm = new ConnectionManager(this);
-    servers = new ServerMap(this);
 
     cm.logChannelInformation();
 
@@ -233,9 +237,6 @@ public class VelocityServer implements ProxyServer {
   }
 
   public Bootstrap initializeGenericBootstrap() {
-    if (cm == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     return this.cm.createWorker();
   }
 
@@ -243,6 +244,87 @@ public class VelocityServer implements ProxyServer {
     return shutdown;
   }
 
+  public boolean reloadConfiguration() throws IOException {
+    Path configPath = Paths.get("velocity.toml");
+    VelocityConfiguration newConfiguration = VelocityConfiguration.read(configPath);
+
+    if (!newConfiguration.validate()) {
+      return false;
+    }
+
+    // Re-register servers. If a server is being replaced, make sure to note what players need to
+    // move back to a fallback server.
+    Collection<ConnectedPlayer> evacuate = new ArrayList<>();
+    for (Map.Entry<String, String> entry : newConfiguration.getServers().entrySet()) {
+      ServerInfo newInfo =
+          new ServerInfo(entry.getKey(), AddressUtil.parseAddress(entry.getValue()));
+      Optional<RegisteredServer> rs = servers.getServer(entry.getKey());
+      if (!rs.isPresent()) {
+        servers.register(newInfo);
+      } else if (!rs.get().getServerInfo().equals(newInfo)) {
+        for (Player player : rs.get().getPlayersConnected()) {
+          if (!(player instanceof ConnectedPlayer)) {
+            throw new IllegalStateException("ConnectedPlayer not found for player " + player
+                + " in server " + rs.get().getServerInfo().getName());
+          }
+          evacuate.add((ConnectedPlayer) player);
+        }
+        servers.unregister(rs.get().getServerInfo());
+        servers.register(newInfo);
+      }
+    }
+
+    // If we had any players to evacuate, let's move them now. Wait until they are all moved off.
+    if (!evacuate.isEmpty()) {
+      CountDownLatch latch = new CountDownLatch(evacuate.size());
+      for (ConnectedPlayer player : evacuate) {
+        Optional<RegisteredServer> next = player.getNextServerToTry();
+        if (next.isPresent()) {
+          player.createConnectionRequest(next.get()).connectWithIndication()
+              .whenComplete((success, ex) -> {
+                if (ex != null || success == null || !success) {
+                  player.disconnect(TextComponent.of("Your server has been changed, but we could "
+                      + "not move you to any fallback servers."));
+                }
+                latch.countDown();
+              });
+        } else {
+          latch.countDown();
+          player.disconnect(TextComponent.of("Your server has been changed, but we could "
+              + "not move you to any fallback servers."));
+        }
+      }
+      try {
+        latch.await();
+      } catch (InterruptedException e) {
+        logger.error("Interrupted whilst moving players", e);
+        Thread.currentThread().interrupt();
+      }
+    }
+
+    // If we have a new bind address, bind to it
+    if (!configuration.getBind().equals(newConfiguration.getBind())) {
+      this.cm.bind(newConfiguration.getBind());
+      this.cm.close(configuration.getBind());
+    }
+
+    if (configuration.isQueryEnabled() && (!newConfiguration.isQueryEnabled()
+        || newConfiguration.getQueryPort() != configuration.getQueryPort())) {
+      this.cm.close(new InetSocketAddress(
+          configuration.getBind().getHostString(), configuration.getQueryPort()));
+    }
+
+    if (newConfiguration.isQueryEnabled()) {
+      this.cm.queryBind(newConfiguration.getBind().getHostString(),
+          newConfiguration.getQueryPort());
+    }
+
+    ipAttemptLimiter = Ratelimiters.createWithMilliseconds(newConfiguration.getLoginRatelimit());
+    this.configuration = newConfiguration;
+    eventManager.fireAndForget(new ProxyReloadEvent());
+    return true;
+  }
+
   public void shutdown(boolean explicitExit) {
     if (eventManager == null || pluginManager == null || cm == null || scheduler == null) {
       throw new AssertionError();
@@ -340,66 +422,41 @@ public class VelocityServer implements ProxyServer {
 
   @Override
   public Optional<RegisteredServer> getServer(String name) {
-    Preconditions.checkNotNull(name, "name");
-    if (servers == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     return servers.getServer(name);
   }
 
   @Override
   public Collection<RegisteredServer> getAllServers() {
-    if (servers == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     return servers.getAllServers();
   }
 
   @Override
   public RegisteredServer registerServer(ServerInfo server) {
-    if (servers == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     return servers.register(server);
   }
 
   @Override
   public void unregisterServer(ServerInfo server) {
-    if (servers == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     servers.unregister(server);
   }
 
   @Override
   public VelocityConsole getConsoleCommandSource() {
-    if (console == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     return console;
   }
 
   @Override
   public PluginManager getPluginManager() {
-    if (pluginManager == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     return pluginManager;
   }
 
   @Override
   public EventManager getEventManager() {
-    if (eventManager == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     return eventManager;
   }
 
   @Override
   public VelocityScheduler getScheduler() {
-    if (scheduler == null) {
-      throw new IllegalStateException("Server did not initialize properly.");
-    }
     return scheduler;
   }
 

proxy/src/main/java/com/velocitypowered/proxy/command/VelocityCommand.java

@@ -10,6 +10,8 @@ import com.velocitypowered.api.plugin.PluginContainer;
 import com.velocitypowered.api.plugin.PluginDescription;
 import com.velocitypowered.api.proxy.ProxyServer;
 import com.velocitypowered.api.util.ProxyVersion;
+import com.velocitypowered.proxy.VelocityServer;
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
@@ -22,6 +24,8 @@ import net.kyori.text.event.HoverEvent;
 import net.kyori.text.event.HoverEvent.Action;
 import net.kyori.text.format.TextColor;
 import net.kyori.text.format.TextDecoration;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.checkerframework.checker.nullness.qual.NonNull;
 
 public class VelocityCommand implements Command {
@@ -32,10 +36,11 @@ public class VelocityCommand implements Command {
    * Initializes the command object for /velocity.
    * @param server the Velocity server
    */
-  public VelocityCommand(ProxyServer server) {
+  public VelocityCommand(VelocityServer server) {
     this.subcommands = ImmutableMap.<String, Command>builder()
         .put("version", new Info(server))
         .put("plugins", new Plugins(server))
+        .put("reload", new Reload(server))
         .build();
   }
 
@@ -103,6 +108,39 @@ public class VelocityCommand implements Command {
     return command.hasPermission(source, actualArgs);
   }
 
+  private static class Reload implements Command {
+
+    private static final Logger logger = LogManager.getLogger(Reload.class);
+    private final VelocityServer server;
+
+    private Reload(VelocityServer server) {
+      this.server = server;
+    }
+
+    @Override
+    public void execute(CommandSource source, String @NonNull [] args) {
+      try {
+        if (server.reloadConfiguration()) {
+          source.sendMessage(TextComponent.of("Configuration reloaded.", TextColor.GREEN));
+        } else {
+          source.sendMessage(TextComponent.of(
+              "Unable to reload your configuration. Check the console for more details.",
+              TextColor.RED));
+        }
+      } catch (Exception e) {
+        logger.error("Unable to reload configuration", e);
+        source.sendMessage(TextComponent.of(
+            "Unable to reload your configuration. Check the console for more details.",
+            TextColor.RED));
+      }
+    }
+
+    @Override
+    public boolean hasPermission(CommandSource source, String @NonNull [] args) {
+      return source.getPermissionValue("velocity.command.reload") == Tristate.TRUE;
+    }
+  }
+
   private static class Info implements Command {
 
     private final ProxyServer server;

proxy/src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -383,7 +383,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation, Player {
     }
   }
 
-  Optional<RegisteredServer> getNextServerToTry() {
+  public Optional<RegisteredServer> getNextServerToTry() {
     if (serversToTry == null) {
       String virtualHostStr = getVirtualHost().map(InetSocketAddress::getHostString).orElse("");
       serversToTry = server.getConfiguration().getForcedHosts()

proxy/src/main/java/com/velocitypowered/proxy/network/ConnectionManager.java

@@ -1,5 +1,6 @@
 package com.velocitypowered.proxy.network;
 
+import com.google.common.base.Preconditions;
 import com.velocitypowered.natives.util.Natives;
 import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.protocol.netty.GS4QueryHandler;
@@ -11,7 +12,9 @@ import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.WriteBufferWaterMark;
 import java.net.InetSocketAddress;
+import java.util.HashMap;
 import java.util.HashSet;
+import java.util.Map;
 import java.util.Set;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -21,7 +24,7 @@ public final class ConnectionManager {
   private static final WriteBufferWaterMark SERVER_WRITE_MARK = new WriteBufferWaterMark(1 << 16,
       1 << 18);
   private static final Logger LOGGER = LogManager.getLogger(ConnectionManager.class);
-  private final Set<Channel> endpoints = new HashSet<>();
+  private final Map<InetSocketAddress, Channel> endpoints = new HashMap<>();
   private final TransportType transportType;
   private final EventLoopGroup bossGroup;
   private final EventLoopGroup workerGroup;
@@ -55,7 +58,7 @@ public final class ConnectionManager {
         .addListener((ChannelFutureListener) future -> {
           final Channel channel = future.channel();
           if (future.isSuccess()) {
-            this.endpoints.add(channel);
+            this.endpoints.put(address, channel);
             LOGGER.info("Listening on {}", channel.localAddress());
           } else {
             LOGGER.error("Can't bind to {}", address, future.cause());
@@ -64,16 +67,17 @@ public final class ConnectionManager {
   }
 
   public void queryBind(final String hostname, final int port) {
+    InetSocketAddress address = new InetSocketAddress(hostname, port);
     final Bootstrap bootstrap = new Bootstrap()
         .channel(this.transportType.datagramChannelClass)
         .group(this.workerGroup)
         .handler(new GS4QueryHandler(this.server))
-        .localAddress(hostname, port);
+        .localAddress(address);
     bootstrap.bind()
         .addListener((ChannelFutureListener) future -> {
           final Channel channel = future.channel();
           if (future.isSuccess()) {
-            this.endpoints.add(channel);
+            this.endpoints.put(address, channel);
             LOGGER.info("Listening for GS4 query on {}", channel.localAddress());
           } else {
             LOGGER.error("Can't bind to {}", bootstrap.config().localAddress(), future.cause());
@@ -90,8 +94,15 @@ public final class ConnectionManager {
             this.server.getConfiguration().getConnectTimeout());
   }
 
+  public void close(InetSocketAddress oldBind) {
+    Channel serverChannel = endpoints.remove(oldBind);
+    Preconditions.checkState(serverChannel != null, "Endpoint %s not registered", oldBind);
+    LOGGER.info("Closing endpoint {}", serverChannel.localAddress());
+    serverChannel.close().syncUninterruptibly();
+  }
+
   public void shutdown() {
-    for (final Channel endpoint : this.endpoints) {
+    for (final Channel endpoint : this.endpoints.values()) {
       try {
         LOGGER.info("Closing endpoint {}", endpoint.localAddress());
         endpoint.close().sync();