diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..39c68bf9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,112 @@
+
+# Created by https://www.toptal.com/developers/gitignore/api/maven,intellij+all
+# Edit at https://www.toptal.com/developers/gitignore?templates=maven,intellij+all
+
+### Intellij+all ###
+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio, WebStorm and Rider
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/**/usage.statistics.xml
+.idea/**/dictionaries
+.idea/**/shelf
+
+# AWS User-specific
+.idea/**/aws.xml
+
+# Generated files
+.idea/**/contentModel.xml
+
+# Sensitive or high-churn files
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+.idea/**/dbnavigator.xml
+
+# Gradle
+.idea/**/gradle.xml
+.idea/**/libraries
+
+# Gradle and Maven with auto-import
+# When using Gradle or Maven with auto-import, you should exclude module files,
+# since they will be recreated, and may cause churn. Uncomment if using
+# auto-import.
+.idea/artifacts
+.idea/compiler.xml
+.idea/jarRepositories.xml
+.idea/modules.xml
+.idea/*.iml
+.idea/modules
+*.iml
+*.ipr
+
+# CMake
+cmake-build-*/
+
+# Mongo Explorer plugin
+.idea/**/mongoSettings.xml
+
+# File-based project format
+*.iws
+
+# IntelliJ
+out/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Cursive Clojure plugin
+.idea/replstate.xml
+
+# SonarLint plugin
+.idea/sonarlint/
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+# Editor-based Rest Client
+.idea/httpRequests
+
+# Android studio 3.1+ serialized cache file
+.idea/caches/build_file_checksums.ser
+
+### Intellij+all Patch ###
+# Ignore everything but code style settings and run configurations
+# that are supposed to be shared within teams.
+
+.idea/*
+
+!.idea/codeStyles
+!.idea/runConfigurations
+
+### Maven ###
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+# https://github.com/takari/maven-wrapper#usage-without-binary-jar
+.mvn/wrapper/maven-wrapper.jar
+
+# Eclipse m2e generated files
+# Eclipse Core
+.project
+# JDT-specific (Eclipse Java Development Tools)
+.classpath
+
+# End of https://www.toptal.com/developers/gitignore/api/maven,intellij+all
\ No newline at end of file
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 00000000..e72bfdda
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,674 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc.
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+ Preamble
+
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+software and other kinds of works.
+
+ The licenses for most software and other practical works are designed
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+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users. We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors. You can apply it to
+your programs, too.
+
+ When we speak of free software, we are referring to freedom, not
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+you modify it: responsibilities to respect the freedom of others.
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+ Developers that use the GNU GPL protect your rights with two steps:
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+ "Additional permissions" are terms that supplement the terms of this
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+
+ You may not propagate or modify a covered work except as expressly
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+modify it is void, and will automatically terminate your rights under
+this License (including any patent licenses granted under the third
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+
+ However, if you cease all violation of this License, then your
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+holder fails to notify you of the violation by some reasonable means
+prior to 60 days after the cessation.
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+reinstated permanently if the copyright holder notifies you of the
+violation by some reasonable means, this is the first time you have
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+copyright holder, and you cure the violation prior to 30 days after
+your receipt of the notice.
+
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+licenses of parties who have received copies or rights from you under
+this License. If your rights have been terminated and not permanently
+reinstated, you do not qualify to receive new licenses for the same
+material under section 10.
+
+ 9. Acceptance Not Required for Having Copies.
+
+ You are not required to accept this License in order to receive or
+run a copy of the Program. Ancillary propagation of a covered work
+occurring solely as a consequence of using peer-to-peer transmission
+to receive a copy likewise does not require acceptance. However,
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+modify any covered work. These actions infringe copyright if you do
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+covered work, you indicate your acceptance of this License to do so.
+
+ 10. Automatic Licensing of Downstream Recipients.
+
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+organization, or merging organizations. If propagation of a covered
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+any patent claim is infringed by making, using, selling, offering for
+sale, or importing the Program or any portion of it.
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+ 11. Patents.
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+ A "contributor" is a copyright holder who authorizes use under this
+License of the Program or a work on which the Program is based. The
+work thus licensed is called the contributor's "contributor version".
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+purposes of this definition, "control" includes the right to grant
+patent sublicenses in a manner consistent with the requirements of
+this License.
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+patent license under the contributor's essential patent claims, to
+make, use, sell, offer for sale, import and otherwise run, modify and
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+ In the following three paragraphs, a "patent license" is any express
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+sue for patent infringement). To "grant" such a patent license to a
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+patent against the party.
+
+ If you convey a covered work, knowingly relying on a patent license,
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+to copy, free of charge and under the terms of this License, through a
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+then you must either (1) cause the Corresponding Source to be so
+available, or (2) arrange to deprive yourself of the benefit of the
+patent license for this particular work, or (3) arrange, in a manner
+consistent with the requirements of this License, to extend the patent
+license to downstream recipients. "Knowingly relying" means you have
+actual knowledge that, but for the patent license, your conveying the
+covered work in a country, or your recipient's use of the covered work
+in a country, would infringe one or more identifiable patents in that
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+arrangement, you convey, or propagate by procuring conveyance of, a
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+you grant is automatically extended to all recipients of the covered
+work and works based on it.
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+ A patent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
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+
+ Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+ 12. No Surrender of Others' Freedom.
+
+ If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License. If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you may
+not convey it at all. For example, if you agree to terms that obligate you
+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
+License would be to refrain entirely from conveying the Program.
+
+ 13. Use with the GNU Affero General Public License.
+
+ Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
+under version 3 of the GNU Affero General Public License into a single
+combined work, and to convey the resulting work. The terms of this
+License will continue to apply to the part which is the covered work,
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
+
+ 14. Revised Versions of this License.
+
+ The Free Software Foundation may publish revised and/or new versions of
+the GNU General Public License from time to time. Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+ Each version is given a distinguishing version number. If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation. If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+ If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+ Later license versions may give you additional or different
+permissions. However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+ 15. Disclaimer of Warranty.
+
+ THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+ 16. Limitation of Liability.
+
+ IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+ 17. Interpretation of Sections 15 and 16.
+
+ If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+
+ Copyright (C)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see .
+
+Also add information on how to contact you by electronic and paper mail.
+
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+ Copyright (C)
+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+ You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+.
+
+ The GNU General Public License does not permit incorporating your program
+into proprietary programs. If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License. But first, please read
+.
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
new file mode 100644
index 00000000..f261de71
--- /dev/null
+++ b/pom.xml
@@ -0,0 +1,102 @@
+
+
+ 4.0.0
+
+ net.azisaba
+ Kuvel
+ 1.0.0
+ jar
+
+ ${project.artifactId}
+ Server-discovery Velocity plugin for Minecraft servers running in a Kubernetes
+ cluster.
+
+
+ https://github.com/AzisabaNetwork/Kuvel
+
+ AzisabaNetwork
+ https://github.com/AzisabaNetwork
+
+
+
+ 17
+ UTF-8
+
+
+
+ ${project.name}
+ clean package
+
+
+ org.apache.maven.plugins
+ maven-compiler-plugin
+ 3.10.0
+
+ ${java.version}
+ ${java.version}
+
+
+
+ org.apache.maven.plugins
+ maven-shade-plugin
+ 3.2.4
+
+
+ package
+
+ shade
+
+
+ false
+
+
+
+
+
+
+
+ src/main/resources
+ true
+
+
+
+
+
+
+ velocity
+ https://nexus.velocitypowered.com/repository/maven-public/
+
+
+
+
+
+ com.velocitypowered
+ velocity-api
+ 3.0.1
+ provided
+
+
+ io.fabric8
+ kubernetes-client
+ 5.12.1
+
+
+ redis.clients
+ jedis
+ 4.1.1
+
+
+ org.apache.commons
+ commons-lang3
+ 3.12.0
+
+
+ org.projectlombok
+ lombok
+ 1.18.22
+ provided
+
+
+
\ No newline at end of file
diff --git a/renovate.json b/renovate.json
new file mode 100644
index 00000000..8adb77ad
--- /dev/null
+++ b/renovate.json
@@ -0,0 +1,6 @@
+{
+ "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+ "extends": [
+ "local>AzisabaNetwork/renovate-config"
+ ]
+}
\ No newline at end of file
diff --git a/src/main/java/net/azisaba/kuvel/Kuvel.java b/src/main/java/net/azisaba/kuvel/Kuvel.java
new file mode 100644
index 00000000..8af9c2fd
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/Kuvel.java
@@ -0,0 +1,147 @@
+package net.azisaba.kuvel;
+
+import com.google.inject.Inject;
+import com.velocitypowered.api.event.Subscribe;
+import com.velocitypowered.api.event.proxy.ProxyInitializeEvent;
+import com.velocitypowered.api.event.proxy.ProxyShutdownEvent;
+import com.velocitypowered.api.plugin.Plugin;
+import com.velocitypowered.api.proxy.ProxyServer;
+import io.fabric8.kubernetes.client.DefaultKubernetesClient;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import java.util.Objects;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Logger;
+import lombok.Getter;
+import net.azisaba.kuvel.config.KuvelConfig;
+import net.azisaba.kuvel.discovery.impl.RedisLoadBalancerDiscovery;
+import net.azisaba.kuvel.discovery.impl.RedisServerDiscovery;
+import net.azisaba.kuvel.discovery.impl.SimpleLoadBalancerDiscovery;
+import net.azisaba.kuvel.discovery.impl.SimpleServerDiscovery;
+import net.azisaba.kuvel.listener.LoadBalancerListener;
+import net.azisaba.kuvel.redis.ProxyIdProvider;
+import net.azisaba.kuvel.redis.RedisConnectionLeader;
+import net.azisaba.kuvel.redis.RedisSubscriber;
+
+@Plugin(
+ id = "kuvel",
+ name = "Kuvel",
+ version = "1.0.0",
+ url = "https://github.com/AzisabaNetwork/Kuvel",
+ description =
+ "Server-discovery Velocity plugin for Minecraft servers running in a Kubernetes cluster.",
+ authors = {"Azisaba Network"})
+@Getter
+public class Kuvel {
+
+ private final ProxyServer proxy;
+ private final Logger logger;
+
+ private final KubernetesClient client = new DefaultKubernetesClient();
+ private KuvelServiceHandler kuvelServiceHandler;
+ private RedisConnectionLeader redisConnectionLeader;
+ private ProxyIdProvider proxyIdProvider;
+ private RedisSubscriber redisSubscriber;
+
+ private KuvelConfig kuvelConfig;
+
+ @Inject
+ public Kuvel(ProxyServer server, Logger logger) {
+ this.proxy = server;
+ this.logger = logger;
+ }
+
+ @Subscribe
+ public void onProxyInitialization(ProxyInitializeEvent event) {
+ kuvelConfig = new KuvelConfig(this);
+ try {
+ kuvelConfig.load();
+ } catch (Exception e) {
+ logger.severe("Failed to load config file. Plugin feature will be disabled.");
+ e.printStackTrace();
+ return;
+ }
+
+ kuvelServiceHandler = new KuvelServiceHandler(this, client);
+ if (kuvelConfig.isRedisEnabled()) {
+ Objects.requireNonNull(kuvelConfig.getRedisConnectionData());
+ Objects.requireNonNull(kuvelConfig.getProxyGroupName());
+
+ proxyIdProvider =
+ new ProxyIdProvider(
+ kuvelConfig.getRedisConnectionData().createJedisPool(),
+ kuvelConfig.getProxyGroupName());
+ proxyIdProvider.runTask(proxy, this);
+
+ redisConnectionLeader =
+ new RedisConnectionLeader(
+ kuvelConfig.getRedisConnectionData().createJedisPool(),
+ kuvelConfig.getProxyGroupName(),
+ proxyIdProvider.getId());
+
+ redisConnectionLeader.trySwitch();
+ if (redisConnectionLeader.isLeader()) {
+ logger.info("This proxy is selected as leader.");
+ }
+ kuvelServiceHandler.setAndRunLoadBalancerDiscovery(
+ new RedisLoadBalancerDiscovery(
+ client,
+ this,
+ kuvelConfig.getRedisConnectionData().createJedisPool(),
+ kuvelConfig.getProxyGroupName(),
+ redisConnectionLeader,
+ kuvelServiceHandler));
+
+ kuvelServiceHandler.setAndRunServerDiscovery(
+ new RedisServerDiscovery(
+ client,
+ this,
+ kuvelConfig.getRedisConnectionData().createJedisPool(),
+ kuvelConfig.getProxyGroupName(),
+ redisConnectionLeader,
+ kuvelServiceHandler));
+
+ proxy
+ .getScheduler()
+ .buildTask(
+ this,
+ () -> {
+ if (redisConnectionLeader.isLeader()) {
+ redisConnectionLeader.extendLeader();
+ } else {
+ redisConnectionLeader.trySwitch();
+ }
+ })
+ .repeat(5, TimeUnit.MINUTES)
+ .schedule();
+
+ redisSubscriber =
+ new RedisSubscriber(
+ kuvelConfig.getRedisConnectionData().createJedisPool(),
+ this,
+ kuvelConfig.getProxyGroupName(),
+ kuvelServiceHandler,
+ redisConnectionLeader);
+ redisSubscriber.subscribe();
+ } else {
+ kuvelServiceHandler.setAndRunLoadBalancerDiscovery(
+ new SimpleLoadBalancerDiscovery(client, this, kuvelServiceHandler));
+ kuvelServiceHandler.setAndRunServerDiscovery(
+ new SimpleServerDiscovery(client, this, kuvelServiceHandler));
+ }
+
+ proxy.getEventManager().register(this, new LoadBalancerListener(this, kuvelServiceHandler));
+ }
+
+ @Subscribe
+ public void onProxyShutdown(ProxyShutdownEvent event) {
+ if (kuvelServiceHandler != null) {
+ kuvelServiceHandler.shutdown();
+ }
+ if (redisConnectionLeader != null) {
+ redisConnectionLeader.leaveLeader();
+ }
+ if (proxyIdProvider != null) {
+ proxyIdProvider.deleteProxyId();
+ }
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/KuvelServiceHandler.java b/src/main/java/net/azisaba/kuvel/KuvelServiceHandler.java
new file mode 100644
index 00000000..829c8876
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/KuvelServiceHandler.java
@@ -0,0 +1,214 @@
+package net.azisaba.kuvel;
+
+import com.velocitypowered.api.proxy.server.ServerInfo;
+import io.fabric8.kubernetes.api.model.Pod;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import java.net.InetSocketAddress;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.Optional;
+import javax.annotation.Nullable;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import net.azisaba.kuvel.discovery.LoadBalancerDiscovery;
+import net.azisaba.kuvel.discovery.ServerDiscovery;
+import net.azisaba.kuvel.loadbalancer.LoadBalancer;
+import net.azisaba.kuvel.util.LabelKeys;
+import net.azisaba.kuvel.util.UidAndServerNameMap;
+
+@Getter
+@RequiredArgsConstructor
+public class KuvelServiceHandler {
+
+ private final Kuvel plugin;
+ private final KubernetesClient client;
+ private final HashMap loadBalancerServerMap = new HashMap<>();
+
+ private final UidAndServerNameMap podUidAndServerNameMap = new UidAndServerNameMap();
+ private final UidAndServerNameMap replicaSetUidAndServerNameMap = new UidAndServerNameMap();
+
+ private ServerDiscovery serverDiscovery;
+ private LoadBalancerDiscovery loadBalancerDiscovery;
+
+ public void registerLoadBalancer(LoadBalancer loadBalancer) {
+ loadBalancerServerMap.put(loadBalancer.getServer().getServerInfo().getName(), loadBalancer);
+ replicaSetUidAndServerNameMap.register(
+ loadBalancer.getReplicaSetUid(), loadBalancer.getServer().getServerInfo().getName());
+ updateLoadBalancerEndpoints(loadBalancer);
+
+ String serverName = loadBalancer.getServer().getServerInfo().getName();
+ plugin
+ .getLogger()
+ .info(
+ "Registered load balancer: "
+ + serverName
+ + " ("
+ + loadBalancer.getReplicaSetUid()
+ + ")");
+ }
+
+ public void unregisterLoadBalancer(String replicaSetUid) {
+ String serverName = replicaSetUidAndServerNameMap.getServerNameFromUid(replicaSetUid);
+ if (serverName == null) {
+ return;
+ }
+ LoadBalancer loadBalancer = loadBalancerServerMap.get(serverName);
+ if (loadBalancer != null) {
+ unregisterLoadBalancer(loadBalancer);
+ }
+ }
+
+ public void unregisterLoadBalancer(LoadBalancer loadBalancer) {
+ String serverName = loadBalancer.getServer().getServerInfo().getName();
+ plugin
+ .getProxy()
+ .getServer(serverName)
+ .ifPresent(server -> plugin.getProxy().unregisterServer(server.getServerInfo()));
+ loadBalancerServerMap.remove(serverName);
+ replicaSetUidAndServerNameMap.unregister(loadBalancer.getReplicaSetUid());
+
+ plugin
+ .getLogger()
+ .info(
+ "Unregistered load balancer: "
+ + serverName
+ + " ("
+ + loadBalancer.getReplicaSetUid()
+ + ")");
+ }
+
+ public Optional getLoadBalancer(String serverName) {
+ return Optional.ofNullable(loadBalancerServerMap.get(serverName));
+ }
+
+ private void updateLoadBalancerEndpoints(LoadBalancer loadBalancer) {
+ List pods =
+ client
+ .pods()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .list()
+ .getItems();
+
+ List endpoints = new ArrayList<>();
+ for (Pod pod : pods) {
+ if (pod.hasOwnerReferenceFor(loadBalancer.getReplicaSetUid())) {
+ String serverName = podUidAndServerNameMap.getServerNameFromUid(pod.getMetadata().getUid());
+ if (serverName != null) {
+ endpoints.add(serverName);
+ }
+ }
+ }
+ loadBalancer.setEndpoints(endpoints);
+ }
+
+ public void setAndRunServerDiscovery(@Nullable ServerDiscovery newServerDiscovery) {
+ if (serverDiscovery != null) {
+ serverDiscovery.shutdown();
+ }
+
+ serverDiscovery = newServerDiscovery;
+ if (serverDiscovery != null) {
+ HashMap servers = serverDiscovery.getServersForStartup();
+ for (Entry entry : servers.entrySet()) {
+ Pod pod = entry.getValue();
+ InetSocketAddress address = new InetSocketAddress(pod.getStatus().getPodIP(), 25565);
+ plugin.getProxy().registerServer(new ServerInfo(entry.getKey(), address));
+
+ for (LoadBalancer loadBalancer : loadBalancerServerMap.values()) {
+ if (pod.hasOwnerReferenceFor(loadBalancer.getReplicaSetUid())) {
+ loadBalancer.addEndpoint(entry.getKey());
+ }
+ }
+ }
+ serverDiscovery.start();
+ }
+ }
+
+ public void setAndRunLoadBalancerDiscovery(
+ @Nullable LoadBalancerDiscovery newLoadBalancerDiscovery) {
+ if (loadBalancerDiscovery != null) {
+ loadBalancerDiscovery.shutdown();
+ }
+
+ loadBalancerDiscovery = newLoadBalancerDiscovery;
+ if (loadBalancerDiscovery != null) {
+ loadBalancerDiscovery.registerLoadBalancersForStartup();
+ loadBalancerDiscovery.start();
+ }
+ }
+
+ public void shutdown() {
+ if (serverDiscovery != null) {
+ serverDiscovery.shutdown();
+ }
+ if (loadBalancerDiscovery != null) {
+ loadBalancerDiscovery.shutdown();
+ }
+ }
+
+ public void registerPod(Pod pod, String serverName) {
+ InetSocketAddress address = new InetSocketAddress(pod.getStatus().getPodIP(), 25565);
+ plugin.getProxy().registerServer(new ServerInfo(serverName, address));
+ podUidAndServerNameMap.register(pod.getMetadata().getUid(), serverName);
+
+ for (LoadBalancer loadBalancer : loadBalancerServerMap.values()) {
+ if (pod.hasOwnerReferenceFor(loadBalancer.getReplicaSetUid())) {
+ loadBalancer.addEndpoint(serverName);
+ }
+ }
+
+ plugin
+ .getLogger()
+ .info("Registered server: " + serverName + " (" + pod.getMetadata().getUid() + ")");
+ }
+
+ public void registerPod(String podUid, String serverName) {
+ Optional pod =
+ client
+ .pods()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .list()
+ .getItems()
+ .stream()
+ .filter(p -> p.getMetadata().getUid().equals(podUid))
+ .findFirst();
+
+ if (!pod.isPresent()) {
+ return;
+ }
+
+ registerPod(pod.get(), serverName);
+ }
+
+ public void unregisterPod(String podUid) {
+ if (podUidAndServerNameMap.getServerNameFromUid(podUid) == null) {
+ return;
+ }
+
+ String serverName = podUidAndServerNameMap.unregister(podUid);
+ plugin
+ .getProxy()
+ .getServer(serverName)
+ .ifPresent(server -> plugin.getProxy().unregisterServer(server.getServerInfo()));
+
+ for (LoadBalancer loadBalancer : loadBalancerServerMap.values()) {
+ if (loadBalancer.getEndpointServers().contains(serverName)) {
+ loadBalancer.removeEndpoint(serverName);
+ }
+ }
+
+ plugin.getLogger().info("Unregistered server: " + serverName + " (" + podUid + ")");
+ }
+
+ public void unregisterPod(Pod pod) {
+ unregisterPod(pod.getMetadata().getUid());
+ }
+
+ public boolean isPodRegistered(String podId) {
+ return podUidAndServerNameMap.getServerNameFromUid(podId) != null;
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/config/KuvelConfig.java b/src/main/java/net/azisaba/kuvel/config/KuvelConfig.java
new file mode 100644
index 00000000..0ac99006
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/config/KuvelConfig.java
@@ -0,0 +1,58 @@
+package net.azisaba.kuvel.config;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.Map;
+import javax.annotation.Nullable;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import net.azisaba.kuvel.Kuvel;
+import net.azisaba.kuvel.util.RedisConnectionData;
+
+@Getter
+@RequiredArgsConstructor
+public class KuvelConfig {
+
+ private final Kuvel plugin;
+
+ private static final String CONFIG_FILE_PATH = "./plugins/Kuvel/config.yml";
+
+ private boolean redisEnabled;
+ @Nullable private RedisConnectionData redisConnectionData;
+ @Nullable private String proxyGroupName;
+
+ public void load() throws IOException {
+ VelocityConfigLoader conf = VelocityConfigLoader.load(new File(CONFIG_FILE_PATH));
+ conf.saveDefaultConfig();
+
+ redisEnabled = conf.getBoolean("redis.enable");
+ if (redisEnabled) {
+ String hostname = conf.getString("redis.connection.hostname");
+ int port = conf.getInt("redis.connection.port", -1);
+ String username = conf.getString("redis.connection.username");
+ String password = conf.getString("redis.connection.password");
+
+ if (hostname == null || port <= 0) {
+ redisEnabled = false;
+ plugin
+ .getLogger()
+ .warning(
+ "Redis is enabled, but hostname or port is invalid. Redis sync will be disabled.");
+ } else {
+ redisConnectionData = new RedisConnectionData(hostname, port, username, password);
+ }
+
+ proxyGroupName = conf.getString("redis.group-name", null);
+ }
+ }
+
+ @SuppressWarnings("unchecked")
+ public Map dig(Map data, String key) throws IOException {
+ Object o = data.get(key);
+ if (!(o instanceof Map)) {
+ throw new IOException("Failed to get new map from key: " + key);
+ }
+
+ return (Map) o;
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/config/VelocityConfigLoader.java b/src/main/java/net/azisaba/kuvel/config/VelocityConfigLoader.java
new file mode 100644
index 00000000..a085a7ff
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/config/VelocityConfigLoader.java
@@ -0,0 +1,179 @@
+package net.azisaba.kuvel.config;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Objects;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+import org.yaml.snakeyaml.Yaml;
+
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+public class VelocityConfigLoader {
+
+ private final File file;
+ private final HashMap dataMap = new HashMap<>();
+
+ public static VelocityConfigLoader load(File file) {
+ return new VelocityConfigLoader(file).load();
+ }
+
+ public String getString(@Nonnull String key, String defaultValue) {
+ String lowerKey = key.toLowerCase(Locale.ROOT);
+ if (dataMap.containsKey(lowerKey)) {
+ return dataMap.get(lowerKey).toString();
+ } else {
+ return defaultValue;
+ }
+ }
+
+ public int getInt(@Nonnull String key, int defaultValue) {
+ String lowerKey = key.toLowerCase(Locale.ROOT);
+ if (dataMap.containsKey(lowerKey)) {
+ return Integer.parseInt(dataMap.get(lowerKey).toString());
+ } else {
+ return defaultValue;
+ }
+ }
+
+ public long getLong(@Nonnull String key, long defaultValue) {
+ String lowerKey = key.toLowerCase(Locale.ROOT);
+ if (dataMap.containsKey(lowerKey)) {
+ return Long.parseLong(dataMap.get(lowerKey).toString());
+ } else {
+ return defaultValue;
+ }
+ }
+
+ public boolean getBoolean(@Nonnull String key, boolean defaultValue) {
+ String lowerKey = key.toLowerCase(Locale.ROOT);
+ if (dataMap.containsKey(lowerKey)) {
+ return Boolean.parseBoolean(dataMap.get(lowerKey).toString());
+ } else {
+ return defaultValue;
+ }
+ }
+
+ public double getDouble(@Nonnull String key, double defaultValue) {
+ String lowerKey = key.toLowerCase(Locale.ROOT);
+ if (dataMap.containsKey(lowerKey)) {
+ return Double.parseDouble(dataMap.get(lowerKey).toString());
+ } else {
+ return defaultValue;
+ }
+ }
+
+ public @Nullable Object get(@Nonnull String key, Object defaultValue) {
+ String lowerKey = key.toLowerCase(Locale.ROOT);
+ return dataMap.getOrDefault(lowerKey, defaultValue);
+ }
+
+ public String getString(@Nonnull String key) {
+ return getString(key, null);
+ }
+
+ public int getInt(@Nonnull String key) {
+ return getInt(key, 0);
+ }
+
+ public long getLong(@Nonnull String key) {
+ return getLong(key, 0);
+ }
+
+ public boolean getBoolean(@Nonnull String key) {
+ return getBoolean(key, false);
+ }
+
+ public double getDouble(@Nonnull String key) {
+ return getDouble(key, 0);
+ }
+
+ public @Nullable Object get(@Nonnull String key) {
+ return get(key, null);
+ }
+
+ private VelocityConfigLoader load() {
+ Objects.requireNonNull(file);
+ String fileName = file.getName().toLowerCase(Locale.ROOT);
+
+ if (!fileName.endsWith(".yml") && !fileName.endsWith(".yaml")) {
+ throw new IllegalArgumentException("File must be a YAML file.");
+ }
+
+ Yaml yaml = new Yaml();
+ Map data;
+ try {
+ if (file.exists()) {
+ data = yaml.load(new FileReader(file));
+ } else {
+ data = new HashMap<>();
+ }
+ } catch (FileNotFoundException e) {
+ throw new IllegalArgumentException("File not found.", e);
+ }
+
+ storeDataFor(null, data);
+ return this;
+ }
+
+ public void saveDefaultConfig() throws IOException {
+ if (file.exists()) {
+ return;
+ }
+
+ InputStream is = getClass().getClassLoader().getResourceAsStream(file.getName());
+ if (is == null) {
+ throw new IllegalStateException("Failed to load config.yml from resource.");
+ }
+ BufferedReader reader = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8));
+ Files.createDirectories(file.getParentFile().toPath());
+
+ byte[] byteStr =
+ reader
+ .lines()
+ .collect(Collectors.joining(System.lineSeparator()))
+ .getBytes(StandardCharsets.UTF_8);
+
+ Files.write(file.toPath(), byteStr);
+
+ load();
+ }
+
+ private void storeDataFor(@Nullable String parentKey, Map map) {
+ for (String key : map.keySet()) {
+ String newKey = parentKey == null ? key : parentKey + "." + key;
+ newKey = newKey.toLowerCase(Locale.ROOT);
+ if (canDig(map, key)) {
+ storeDataFor(newKey, dig(map, key));
+ } else {
+ dataMap.put(newKey, map.get(key));
+ }
+ }
+ }
+
+ private boolean canDig(Map map, String key) {
+ return map.get(key) instanceof Map;
+ }
+
+ @SuppressWarnings("unchecked")
+ private Map dig(Map data, String key) {
+ Object o = data.get(key);
+ if (!(o instanceof Map)) {
+ throw new IllegalArgumentException("Cannot dig.");
+ }
+
+ return (Map) o;
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/discovery/LoadBalancerDiscovery.java b/src/main/java/net/azisaba/kuvel/discovery/LoadBalancerDiscovery.java
new file mode 100644
index 00000000..276d87d7
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/discovery/LoadBalancerDiscovery.java
@@ -0,0 +1,10 @@
+package net.azisaba.kuvel.discovery;
+
+public interface LoadBalancerDiscovery {
+
+ void start();
+
+ void shutdown();
+
+ void registerLoadBalancersForStartup();
+}
diff --git a/src/main/java/net/azisaba/kuvel/discovery/ServerDiscovery.java b/src/main/java/net/azisaba/kuvel/discovery/ServerDiscovery.java
new file mode 100644
index 00000000..f57b9da5
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/discovery/ServerDiscovery.java
@@ -0,0 +1,14 @@
+package net.azisaba.kuvel.discovery;
+
+import io.fabric8.kubernetes.api.model.Pod;
+import java.net.InetSocketAddress;
+import java.util.HashMap;
+
+public interface ServerDiscovery {
+
+ void start();
+
+ void shutdown();
+
+ HashMap getServersForStartup();
+}
diff --git a/src/main/java/net/azisaba/kuvel/discovery/impl/RedisLoadBalancerDiscovery.java b/src/main/java/net/azisaba/kuvel/discovery/impl/RedisLoadBalancerDiscovery.java
new file mode 100644
index 00000000..5bd06a08
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/discovery/impl/RedisLoadBalancerDiscovery.java
@@ -0,0 +1,215 @@
+package net.azisaba.kuvel.discovery.impl;
+
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import com.velocitypowered.api.proxy.server.ServerInfo;
+import io.fabric8.kubernetes.api.model.apps.ReplicaSet;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.Watcher;
+import io.fabric8.kubernetes.client.WatcherException;
+import java.net.InetSocketAddress;
+import java.util.Collection;
+import java.util.Map;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.ReentrantLock;
+import lombok.RequiredArgsConstructor;
+import net.azisaba.kuvel.Kuvel;
+import net.azisaba.kuvel.KuvelServiceHandler;
+import net.azisaba.kuvel.discovery.LoadBalancerDiscovery;
+import net.azisaba.kuvel.loadbalancer.LoadBalancer;
+import net.azisaba.kuvel.loadbalancer.strategy.impl.RoundRobinLoadBalancingStrategy;
+import net.azisaba.kuvel.redis.RedisConnectionLeader;
+import net.azisaba.kuvel.redis.RedisKeys;
+import net.azisaba.kuvel.util.LabelKeys;
+import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisPool;
+
+@RequiredArgsConstructor
+public class RedisLoadBalancerDiscovery implements LoadBalancerDiscovery {
+
+ private final KubernetesClient client;
+ private final Kuvel plugin;
+ private final JedisPool jedisPool;
+ private final String groupName;
+ private final RedisConnectionLeader redisConnectionLeader;
+ private final KuvelServiceHandler kuvelServiceHandler;
+
+ private final ExecutorService serverDiscoveryExecutor = Executors.newFixedThreadPool(1);
+ private final ReentrantLock lock = new ReentrantLock();
+
+ @Override
+ public void start() {
+ if (!redisConnectionLeader.isLeader()) {
+ return;
+ }
+
+ run(
+ serverDiscoveryExecutor,
+ () ->
+ client
+ .apps()
+ .replicaSets()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .withLabel(LabelKeys.SERVER_NAME.getKey())
+ .watch(
+ new Watcher() {
+ @Override
+ public void eventReceived(Action action, ReplicaSet replicaSet) {
+ lock.lock();
+ try {
+ if (action == Action.ADDED) {
+ registerOrIgnore(replicaSet);
+ } else if (action == Action.DELETED) {
+ unregisterOrIgnore(replicaSet);
+ }
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ @Override
+ public void onClose(WatcherException e) {}
+ }));
+ }
+
+ private void registerOrIgnore(ReplicaSet replicaSet) {
+ registerOrIgnore(replicaSet, false);
+ }
+
+ private void registerOrIgnore(ReplicaSet replicaSet, boolean isFetchedFromRedis) {
+ String uid = replicaSet.getMetadata().getUid();
+ if (kuvelServiceHandler.getReplicaSetUidAndServerNameMap().getServerNameFromUid(uid) != null) {
+ return;
+ }
+
+ String serverName =
+ replicaSet.getMetadata().getLabels().getOrDefault(LabelKeys.SERVER_NAME.getKey(), null);
+ if (serverName == null) {
+ return;
+ }
+
+ try (Jedis jedis = jedisPool.getResource()) {
+ if (!isFetchedFromRedis) {
+ Collection loadBalancerNames =
+ jedis.hgetAll(RedisKeys.LOAD_BALANCERS_PREFIX.getKey() + groupName).values();
+
+ if (loadBalancerNames.contains(serverName)
+ || plugin.getProxy().getServer(serverName).isPresent()) {
+ plugin
+ .getLogger()
+ .info("Failed to add load balancer. Server name already occupied: " + serverName);
+ return;
+ }
+ }
+
+ kuvelServiceHandler.getReplicaSetUidAndServerNameMap().register(uid, serverName);
+ jedis.hset(RedisKeys.LOAD_BALANCERS_PREFIX.getKey() + groupName, uid, serverName);
+
+ redisConnectionLeader.publishNewLoadBalancer(uid, serverName);
+
+ RegisteredServer server =
+ plugin
+ .getProxy()
+ .registerServer(new ServerInfo(serverName, new InetSocketAddress("0.0.0.0", 0)));
+
+ kuvelServiceHandler.registerLoadBalancer(
+ new LoadBalancer(plugin.getProxy(), server, new RoundRobinLoadBalancingStrategy(), uid));
+ }
+ }
+
+ private void unregisterOrIgnore(ReplicaSet replicaSet) {
+ String uid = replicaSet.getMetadata().getUid();
+ if (kuvelServiceHandler.getReplicaSetUidAndServerNameMap().getServerNameFromUid(uid) == null) {
+ return;
+ }
+
+ kuvelServiceHandler.unregisterLoadBalancer(uid);
+ // podUidAndServerNameMap.unregister(uid); // no need
+ redisConnectionLeader.publishDeletedLoadBalancer(replicaSet.getMetadata().getUid());
+
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.hdel(RedisKeys.LOAD_BALANCERS_PREFIX.getKey() + groupName, uid);
+ }
+ }
+
+ @Override
+ public void shutdown() {
+ serverDiscoveryExecutor.shutdownNow();
+ }
+
+ @Override
+ public void registerLoadBalancersForStartup() {
+ if (redisConnectionLeader.isLeader()) {
+ try (Jedis jedis = jedisPool.getResource()) {
+ Map uidAndServerNameMapInRedis =
+ jedis.hgetAll(RedisKeys.LOAD_BALANCERS_PREFIX.getKey() + groupName);
+ for (Map.Entry entry : uidAndServerNameMapInRedis.entrySet()) {
+ ReplicaSet replicaSet = getReplicaSetFromUid(entry.getKey());
+ if (replicaSet == null) {
+ jedis.hdel(RedisKeys.LOAD_BALANCERS_PREFIX.getKey() + groupName, entry.getKey());
+ continue;
+ }
+ registerOrIgnore(replicaSet, true);
+ }
+
+ client
+ .apps()
+ .replicaSets()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .withLabel(LabelKeys.SERVER_NAME.getKey())
+ .list()
+ .getItems()
+ .stream()
+ .filter(
+ replicaSet ->
+ !uidAndServerNameMapInRedis.containsKey(replicaSet.getMetadata().getUid()))
+ .forEach(this::registerOrIgnore);
+ }
+ } else {
+ try (Jedis jedis = jedisPool.getResource()) {
+ Map uidAndServerNameMapInRedis =
+ jedis.hgetAll(RedisKeys.LOAD_BALANCERS_PREFIX.getKey() + groupName);
+ for (Map.Entry entry : uidAndServerNameMapInRedis.entrySet()) {
+ ReplicaSet replicaSet = getReplicaSetFromUid(entry.getKey());
+ if (replicaSet == null) {
+ continue;
+ }
+ registerOrIgnore(replicaSet, true);
+ }
+ }
+ }
+ }
+
+ private ReplicaSet getReplicaSetFromUid(String uid) {
+ return client
+ .apps()
+ .replicaSets()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .withLabel(LabelKeys.SERVER_NAME.getKey())
+ .list()
+ .getItems()
+ .stream()
+ .filter(replicaSet -> replicaSet.getMetadata().getUid().equals(uid))
+ .findAny()
+ .orElse(null);
+ }
+
+ private void run(ExecutorService service, Runnable runnable) {
+ service.submit(runnable);
+ for (int i = 0; i < 1000; i++) {
+ service.submit(
+ () -> {
+ try {
+ Thread.sleep(3000);
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ }
+
+ runnable.run();
+ });
+ }
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/discovery/impl/RedisServerDiscovery.java b/src/main/java/net/azisaba/kuvel/discovery/impl/RedisServerDiscovery.java
new file mode 100644
index 00000000..fcd60cd7
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/discovery/impl/RedisServerDiscovery.java
@@ -0,0 +1,256 @@
+package net.azisaba.kuvel.discovery.impl;
+
+import io.fabric8.kubernetes.api.model.Pod;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.Watcher;
+import io.fabric8.kubernetes.client.WatcherException;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.function.Function;
+import lombok.RequiredArgsConstructor;
+import net.azisaba.kuvel.Kuvel;
+import net.azisaba.kuvel.KuvelServiceHandler;
+import net.azisaba.kuvel.discovery.ServerDiscovery;
+import net.azisaba.kuvel.redis.RedisConnectionLeader;
+import net.azisaba.kuvel.redis.RedisKeys;
+import net.azisaba.kuvel.util.LabelKeys;
+import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisPool;
+
+@RequiredArgsConstructor
+public class RedisServerDiscovery implements ServerDiscovery {
+
+ private final KubernetesClient client;
+ private final Kuvel plugin;
+ private final JedisPool jedisPool;
+ private final String groupName;
+ private final RedisConnectionLeader redisConnectionLeader;
+ private final KuvelServiceHandler kuvelServiceHandler;
+
+ private final ExecutorService serverDiscoveryExecutor = Executors.newFixedThreadPool(1);
+ private final ReentrantLock lock = new ReentrantLock();
+
+ @Override
+ public void start() {
+ if (!redisConnectionLeader.isLeader()) {
+ return;
+ }
+
+ run(
+ serverDiscoveryExecutor,
+ () ->
+ client
+ .pods()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .withField("status.phase", "Running")
+ .watch(
+ new Watcher() {
+ @Override
+ public void eventReceived(Action action, Pod pod) {
+ lock.lock();
+ try {
+ if (action == Action.ADDED) {
+ registerPodOrIgnore(pod);
+ } else if (action == Action.DELETED) {
+ unregisterPodOrIgnore(pod);
+ }
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ @Override
+ public void onClose(WatcherException e) {}
+ }));
+ }
+
+ @Override
+ public void shutdown() {
+ serverDiscoveryExecutor.shutdownNow();
+ }
+
+ @Override
+ public HashMap getServersForStartup() {
+ Map podIdToServerNameMap;
+ if (redisConnectionLeader.isLeader()) {
+ try (Jedis jedis = jedisPool.getResource()) {
+ podIdToServerNameMap = new HashMap<>(jedis.hgetAll(RedisKeys.SERVERS_PREFIX + groupName));
+
+ for (String podUid : new ArrayList<>(podIdToServerNameMap.keySet())) {
+ if (getPodUsingPodUid(podUid) == null) {
+ podIdToServerNameMap.remove(podUid);
+ jedis.hdel(RedisKeys.SERVERS_PREFIX + groupName, podUid);
+ redisConnectionLeader.publishDeletedServer(podUid);
+ }
+ }
+
+ Map loadBalancerMap =
+ jedis.hgetAll(RedisKeys.LOAD_BALANCERS_PREFIX.getKey() + groupName);
+
+ client
+ .pods()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .withField("status.phase", "Running")
+ .list()
+ .getItems()
+ .forEach(
+ pod -> {
+ String uid = pod.getMetadata().getUid();
+ if (podIdToServerNameMap.containsKey(uid)) {
+ return;
+ }
+
+ String preferServerName =
+ pod.getMetadata()
+ .getLabels()
+ .getOrDefault(
+ LabelKeys.SERVER_NAME.getKey(), pod.getMetadata().getName());
+ String serverName =
+ getValidServerName(
+ preferServerName,
+ (name) ->
+ !podIdToServerNameMap.containsValue(name)
+ && !loadBalancerMap.containsValue(name)
+ && !plugin.getProxy().getServer(name).isPresent());
+
+ podIdToServerNameMap.put(uid, serverName);
+ jedis.hset(RedisKeys.SERVERS_PREFIX + groupName, uid, serverName);
+ });
+ }
+ } else {
+ try (Jedis jedis = jedisPool.getResource()) {
+ podIdToServerNameMap = jedis.hgetAll(RedisKeys.SERVERS_PREFIX + groupName);
+ }
+ }
+
+ String verb = "Fetched";
+ if (redisConnectionLeader.isLeader()) {
+ verb = "Found";
+ }
+
+ for (String podUid : podIdToServerNameMap.keySet()) {
+ plugin
+ .getLogger()
+ .info(verb + " server: " + podIdToServerNameMap.get(podUid) + " (" + podUid + ")");
+ }
+
+ HashMap servers = new HashMap<>();
+ for (Entry entry : podIdToServerNameMap.entrySet()) {
+ Pod pod = getPodUsingPodUid(entry.getKey());
+ if (pod == null) {
+ continue;
+ }
+
+ servers.put(entry.getValue(), pod);
+ kuvelServiceHandler.getPodUidAndServerNameMap().register(entry.getKey(), entry.getValue());
+ }
+ return servers;
+ }
+
+ private void registerPodOrIgnore(Pod pod) {
+ String uid = pod.getMetadata().getUid();
+ if (kuvelServiceHandler.getPodUidAndServerNameMap().getServerNameFromUid(uid) != null) {
+ return;
+ }
+
+ String serverName;
+
+ try (Jedis jedis = jedisPool.getResource()) {
+ Map serverMap = jedis.hgetAll(RedisKeys.SERVERS_PREFIX.getKey() + groupName);
+ Map loadBalancerMap =
+ jedis.hgetAll(RedisKeys.LOAD_BALANCERS_PREFIX.getKey() + groupName);
+
+ String preferServerName =
+ pod.getMetadata()
+ .getLabels()
+ .getOrDefault(LabelKeys.SERVER_NAME.getKey(), pod.getMetadata().getName());
+
+ serverName =
+ getValidServerName(
+ preferServerName,
+ (name) ->
+ !serverMap.containsValue(name)
+ && !loadBalancerMap.containsValue(name)
+ && !plugin.getProxy().getServer(name).isPresent());
+
+ kuvelServiceHandler.getPodUidAndServerNameMap().register(uid, serverName);
+ jedis.hset(RedisKeys.SERVERS_PREFIX.getKey() + groupName, uid, serverName);
+
+ redisConnectionLeader.publishNewServer(uid, serverName);
+ kuvelServiceHandler.registerPod(pod, serverName);
+ }
+ }
+
+ private void unregisterPodOrIgnore(Pod pod) {
+ String uid = pod.getMetadata().getUid();
+ if (kuvelServiceHandler.getPodUidAndServerNameMap().getServerNameFromUid(uid) == null) {
+ return;
+ }
+
+ kuvelServiceHandler.unregisterPod(uid);
+ // podUidAndServerNameMap.unregister(uid); // no need
+ redisConnectionLeader.publishDeletedServer(pod.getMetadata().getUid());
+
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.hdel(RedisKeys.SERVERS_PREFIX.getKey() + groupName, uid);
+ }
+ }
+
+ private Pod getPodUsingPodUid(String podUid) {
+ return client.pods().list().getItems().stream()
+ .filter(pod -> pod.getMetadata().getUid().equals(podUid))
+ .findFirst()
+ .orElse(null);
+ }
+
+ private String getValidServerName(String prefer, Function isValid) {
+ if (isValid.apply(prefer)) {
+ return prefer;
+ }
+
+ String name = prefer + "-1";
+ int i = 1;
+ while (!isValid.apply(name)) {
+ name = name.substring(0, name.length() - (1 + String.valueOf(i).length())) + "-" + (i + 1);
+ i++;
+ }
+ return name;
+ }
+
+ private String getValidServerNameComparingRegisteredServers(String prefer) {
+ if (!plugin.getProxy().getServer(prefer).isPresent()) {
+ return prefer;
+ }
+
+ String name = prefer + "-1";
+ int i = 1;
+ while (plugin.getProxy().getServer(name).isPresent()) {
+ name = name.substring(0, name.length() - (1 + String.valueOf(i).length())) + "-" + (i + 1);
+ i++;
+ }
+ return name;
+ }
+
+ private void run(ExecutorService service, Runnable runnable) {
+ service.submit(runnable);
+ for (int i = 0; i < 1000; i++) {
+ service.submit(
+ () -> {
+ try {
+ Thread.sleep(3000);
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ }
+
+ runnable.run();
+ });
+ }
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/discovery/impl/SimpleLoadBalancerDiscovery.java b/src/main/java/net/azisaba/kuvel/discovery/impl/SimpleLoadBalancerDiscovery.java
new file mode 100644
index 00000000..33af6f60
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/discovery/impl/SimpleLoadBalancerDiscovery.java
@@ -0,0 +1,129 @@
+package net.azisaba.kuvel.discovery.impl;
+
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import com.velocitypowered.api.proxy.server.ServerInfo;
+import io.fabric8.kubernetes.api.model.apps.ReplicaSet;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.Watcher;
+import io.fabric8.kubernetes.client.WatcherException;
+import java.net.InetSocketAddress;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.ReentrantLock;
+import lombok.RequiredArgsConstructor;
+import net.azisaba.kuvel.Kuvel;
+import net.azisaba.kuvel.KuvelServiceHandler;
+import net.azisaba.kuvel.discovery.LoadBalancerDiscovery;
+import net.azisaba.kuvel.loadbalancer.LoadBalancer;
+import net.azisaba.kuvel.loadbalancer.strategy.impl.RoundRobinLoadBalancingStrategy;
+import net.azisaba.kuvel.util.LabelKeys;
+
+@RequiredArgsConstructor
+public class SimpleLoadBalancerDiscovery implements LoadBalancerDiscovery {
+
+ private final KubernetesClient client;
+ private final Kuvel plugin;
+ private final KuvelServiceHandler kuvelServiceHandler;
+
+ private final ExecutorService loadBalancerDiscoveryExecutor = Executors.newFixedThreadPool(1);
+ private final ReentrantLock lock = new ReentrantLock();
+
+ @Override
+ public void start() {
+ run(
+ loadBalancerDiscoveryExecutor,
+ () ->
+ client
+ .apps()
+ .replicaSets()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .withLabel(LabelKeys.SERVER_NAME.getKey())
+ .watch(
+ new Watcher() {
+ @Override
+ public void eventReceived(Action action, ReplicaSet replicaSet) {
+ lock.lock();
+ try {
+ if (action == Action.ADDED) {
+ registerOrIgnore(replicaSet);
+ } else if (action == Action.DELETED) {
+ unregisterOrIgnore(replicaSet);
+ }
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ @Override
+ public void onClose(WatcherException e) {}
+ }));
+ }
+
+ @Override
+ public void shutdown() {
+ loadBalancerDiscoveryExecutor.shutdownNow();
+ }
+
+ @Override
+ public void registerLoadBalancersForStartup() {
+ client
+ .apps()
+ .replicaSets()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .withLabel(LabelKeys.SERVER_NAME.getKey())
+ .list()
+ .getItems()
+ .forEach(this::registerOrIgnore);
+ }
+
+ private void registerOrIgnore(ReplicaSet replicaSet) {
+ String uid = replicaSet.getMetadata().getUid();
+ if (kuvelServiceHandler.getReplicaSetUidAndServerNameMap().getServerNameFromUid(uid) != null) {
+ return;
+ }
+
+ String serverName = replicaSet.getMetadata().getLabels().get(LabelKeys.SERVER_NAME.getKey());
+
+ if (plugin.getProxy().getServer(serverName).isPresent()) {
+ plugin
+ .getLogger()
+ .info("Failed to add load balancer. Server name already occupied: " + serverName);
+ return;
+ }
+ RegisteredServer server =
+ plugin
+ .getProxy()
+ .registerServer(new ServerInfo(serverName, new InetSocketAddress("0.0.0.0", 0)));
+
+ LoadBalancer loadBalancer =
+ new LoadBalancer(plugin.getProxy(), server, new RoundRobinLoadBalancingStrategy(), uid);
+ kuvelServiceHandler.registerLoadBalancer(loadBalancer);
+ }
+
+ public void unregisterOrIgnore(ReplicaSet replicaSet) {
+ String uid = replicaSet.getMetadata().getUid();
+ if (kuvelServiceHandler.getReplicaSetUidAndServerNameMap().getServerNameFromUid(uid) == null) {
+ return;
+ }
+
+ kuvelServiceHandler.unregisterLoadBalancer(uid);
+ }
+
+ private void run(ExecutorService service, Runnable runnable) {
+ service.submit(runnable);
+ for (int i = 0; i < 1000; i++) {
+ service.submit(
+ () -> {
+ try {
+ Thread.sleep(3000);
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ }
+
+ runnable.run();
+ });
+ }
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/discovery/impl/SimpleServerDiscovery.java b/src/main/java/net/azisaba/kuvel/discovery/impl/SimpleServerDiscovery.java
new file mode 100644
index 00000000..7df53b7d
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/discovery/impl/SimpleServerDiscovery.java
@@ -0,0 +1,153 @@
+package net.azisaba.kuvel.discovery.impl;
+
+import io.fabric8.kubernetes.api.model.Pod;
+import io.fabric8.kubernetes.client.KubernetesClient;
+import io.fabric8.kubernetes.client.Watcher;
+import io.fabric8.kubernetes.client.WatcherException;
+import java.util.HashMap;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.locks.ReentrantLock;
+import lombok.RequiredArgsConstructor;
+import net.azisaba.kuvel.Kuvel;
+import net.azisaba.kuvel.KuvelServiceHandler;
+import net.azisaba.kuvel.discovery.ServerDiscovery;
+import net.azisaba.kuvel.util.LabelKeys;
+
+@RequiredArgsConstructor
+public class SimpleServerDiscovery implements ServerDiscovery {
+
+ private final KubernetesClient client;
+ private final Kuvel plugin;
+ private final KuvelServiceHandler kuvelServiceHandler;
+
+ private final ExecutorService serverDiscoveryExecutor = Executors.newFixedThreadPool(1);
+
+ private final ReentrantLock lock = new ReentrantLock();
+
+ @Override
+ public void start() {
+ run(
+ serverDiscoveryExecutor,
+ () ->
+ client
+ .pods()
+ .inAnyNamespace()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .withField("status.phase", "Running")
+ .watch(
+ new Watcher() {
+ @Override
+ public void eventReceived(Action action, Pod pod) {
+ lock.lock();
+ try {
+ if (action == Action.ADDED) {
+ registerPodOrIgnore(pod);
+ } else if (action == Action.DELETED) {
+ unregisterPodOrIgnore(pod);
+ }
+ } finally {
+ lock.unlock();
+ }
+ }
+
+ @Override
+ public void onClose(WatcherException e) {}
+ }));
+ }
+
+ @Override
+ public void shutdown() {
+ serverDiscoveryExecutor.shutdownNow();
+ }
+
+ @Override
+ public HashMap getServersForStartup() {
+ HashMap servers = new HashMap<>();
+ client
+ .pods()
+ .withLabel(LabelKeys.SERVER_DISCOVERY.getKey(), "true")
+ .list()
+ .getItems()
+ .forEach(
+ pod -> {
+ String uid = pod.getMetadata().getUid();
+ String serverName =
+ pod.getMetadata()
+ .getLabels()
+ .getOrDefault(LabelKeys.SERVER_NAME.getKey(), pod.getMetadata().getUid());
+
+ if (servers.containsKey(serverName)
+ || plugin.getProxy().getServer(serverName).isPresent()) {
+ serverName += "-1";
+ int i = 1;
+ while (servers.containsKey(serverName)
+ && !plugin.getProxy().getServer(serverName).isPresent()) {
+ serverName =
+ serverName.substring(
+ 0, serverName.length() - (1 + String.valueOf(i).length()))
+ + "-"
+ + (i + 1);
+ i++;
+ }
+ }
+ servers.put(serverName, pod);
+ kuvelServiceHandler.getPodUidAndServerNameMap().register(uid, serverName);
+
+ plugin.getLogger().info("Found server: " + serverName + " (" + uid + ")");
+ });
+
+ return servers;
+ }
+
+ private void registerPodOrIgnore(Pod pod) {
+ String uid = pod.getMetadata().getUid();
+ if (kuvelServiceHandler.getPodUidAndServerNameMap().getServerNameFromUid(uid) != null) {
+ return;
+ }
+
+ String serverName =
+ getValidServerName(
+ pod.getMetadata()
+ .getLabels()
+ .getOrDefault(LabelKeys.SERVER_NAME.getKey(), pod.getMetadata().getName()));
+
+ kuvelServiceHandler.getPodUidAndServerNameMap().register(uid, serverName);
+ kuvelServiceHandler.registerPod(pod, serverName);
+ }
+
+ private void unregisterPodOrIgnore(Pod pod) {
+ kuvelServiceHandler.unregisterPod(pod);
+ // podUidAndServerNameMap.unregister(uid); // no need
+ }
+
+ private void run(ExecutorService service, Runnable runnable) {
+ service.submit(runnable);
+ for (int i = 0; i < 1000; i++) {
+ service.submit(
+ () -> {
+ try {
+ Thread.sleep(3000);
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ }
+
+ runnable.run();
+ });
+ }
+ }
+
+ private String getValidServerName(String prefer) {
+ if (!plugin.getProxy().getServer(prefer).isPresent()) {
+ return prefer;
+ }
+
+ String name = prefer + "-1";
+ int i = 1;
+ while (plugin.getProxy().getServer(name).isPresent()) {
+ name = name.substring(0, name.length() - (1 + String.valueOf(i).length())) + "-" + (i + 1);
+ i++;
+ }
+ return name;
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/listener/LoadBalancerListener.java b/src/main/java/net/azisaba/kuvel/listener/LoadBalancerListener.java
new file mode 100644
index 00000000..379f4cec
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/listener/LoadBalancerListener.java
@@ -0,0 +1,59 @@
+package net.azisaba.kuvel.listener;
+
+import com.velocitypowered.api.event.PostOrder;
+import com.velocitypowered.api.event.Subscribe;
+import com.velocitypowered.api.event.player.PlayerChooseInitialServerEvent;
+import com.velocitypowered.api.event.player.ServerPreConnectEvent;
+import com.velocitypowered.api.event.player.ServerPreConnectEvent.ServerResult;
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import lombok.RequiredArgsConstructor;
+import net.azisaba.kuvel.Kuvel;
+import net.azisaba.kuvel.KuvelServiceHandler;
+
+@RequiredArgsConstructor
+public class LoadBalancerListener {
+
+ private final Kuvel plugin;
+ private final KuvelServiceHandler handler;
+
+ @Subscribe(order = PostOrder.LATE)
+ public void onServerChanged(PlayerChooseInitialServerEvent event) {
+ event
+ .getInitialServer()
+ .ifPresent(
+ server -> {
+ String serverName = server.getServerInfo().getName();
+ handler
+ .getLoadBalancer(serverName)
+ .ifPresent(
+ lb -> {
+ RegisteredServer target = lb.getTarget();
+ if (target != null) {
+ event.setInitialServer(target);
+ }
+ });
+ });
+ }
+
+ @Subscribe(order = PostOrder.LATE)
+ public void onServerChanged(ServerPreConnectEvent event) {
+ event
+ .getResult()
+ .getServer()
+ .ifPresent(
+ server -> {
+ String serverName = server.getServerInfo().getName();
+ handler
+ .getLoadBalancer(serverName)
+ .ifPresent(
+ lb -> {
+ RegisteredServer target = lb.getTarget();
+ if (target != null) {
+ event.setResult(ServerResult.allowed(target));
+ } else {
+ event.setResult(ServerResult.denied());
+ }
+ });
+ });
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/loadbalancer/LoadBalancer.java b/src/main/java/net/azisaba/kuvel/loadbalancer/LoadBalancer.java
new file mode 100644
index 00000000..d847e6d6
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/loadbalancer/LoadBalancer.java
@@ -0,0 +1,57 @@
+package net.azisaba.kuvel.loadbalancer;
+
+import com.velocitypowered.api.proxy.ProxyServer;
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public class LoadBalancer {
+
+ private final ProxyServer proxy;
+ private final RegisteredServer server;
+ private final LoadBalancingStrategy strategy;
+ private final String replicaSetUid;
+
+ private final List endpointServers = new ArrayList<>();
+
+ public void addEndpoint(String serverName) {
+ if (!endpointServers.contains(serverName)) {
+ endpointServers.add(serverName);
+ }
+ }
+
+ public void removeEndpoint(String serverName) {
+ endpointServers.remove(serverName);
+ }
+
+ public void setEndpoints(List endpoints) {
+ endpointServers.clear();
+ endpointServers.addAll(endpoints);
+ }
+
+ public RegisteredServer getTarget() {
+ List servers =
+ endpointServers.stream()
+ .map(name -> proxy.getServer(name).orElse(null))
+ .filter(Objects::nonNull)
+ .collect(Collectors.toList());
+
+ return strategy.choose(servers);
+ }
+
+ // public List getTargets(int count) {
+ // List servers =
+ // endpointServers.stream()
+ // .map(name -> proxy.getServer(name).orElse(null))
+ // .filter(Objects::nonNull)
+ // .collect(Collectors.toList());
+ //
+ // return strategy.choose(servers, count);
+ // }
+}
diff --git a/src/main/java/net/azisaba/kuvel/loadbalancer/LoadBalancingStrategy.java b/src/main/java/net/azisaba/kuvel/loadbalancer/LoadBalancingStrategy.java
new file mode 100644
index 00000000..087a3709
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/loadbalancer/LoadBalancingStrategy.java
@@ -0,0 +1,11 @@
+package net.azisaba.kuvel.loadbalancer;
+
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import java.util.List;
+
+public interface LoadBalancingStrategy {
+
+ RegisteredServer choose(List servers);
+
+ // List choose(List servers, int count);
+}
diff --git a/src/main/java/net/azisaba/kuvel/loadbalancer/VirtualLoadBalancerContainer.java b/src/main/java/net/azisaba/kuvel/loadbalancer/VirtualLoadBalancerContainer.java
new file mode 100644
index 00000000..7209e388
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/loadbalancer/VirtualLoadBalancerContainer.java
@@ -0,0 +1,13 @@
+package net.azisaba.kuvel.loadbalancer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class VirtualLoadBalancerContainer {
+
+ private final List servers = new ArrayList<>();
+
+ public void addServer(LoadBalancer server) {
+ servers.add(server);
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/loadbalancer/strategy/impl/MinimumPlayerLoadBalancingStrategy.java b/src/main/java/net/azisaba/kuvel/loadbalancer/strategy/impl/MinimumPlayerLoadBalancingStrategy.java
new file mode 100644
index 00000000..26f80e77
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/loadbalancer/strategy/impl/MinimumPlayerLoadBalancingStrategy.java
@@ -0,0 +1,54 @@
+package net.azisaba.kuvel.loadbalancer.strategy.impl;
+
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import java.util.Comparator;
+import java.util.List;
+import net.azisaba.kuvel.loadbalancer.LoadBalancingStrategy;
+
+public class MinimumPlayerLoadBalancingStrategy implements LoadBalancingStrategy {
+
+ @Override
+ public RegisteredServer choose(List servers) {
+ if (servers.isEmpty()) {
+ return null;
+ }
+
+ return servers.stream()
+ .min(Comparator.comparingInt(a -> a.getPlayersConnected().size()))
+ .orElse(null);
+ }
+
+ // @Override
+ // public List choose(List servers, int count) {
+ // List chosenServers = new ArrayList<>();
+ // HashMap addedPlayerCount = new HashMap<>();
+ //
+ // for (int i = 0; i < count; i++) {
+ // RegisteredServer server =
+ // servers.stream()
+ // .min(
+ // (server1, server2) -> {
+ // int server1Count =
+ // server1.getPlayersConnected().size()
+ // + addedPlayerCount.getOrDefault(server1.getServerInfo().getName(),
+ // 0);
+ // int server2Count =
+ // server2.getPlayersConnected().size()
+ // + addedPlayerCount.getOrDefault(server2.getServerInfo().getName(),
+ // 0);
+ // return server1Count - server2Count;
+ // })
+ // .orElse(null);
+ // if (server == null) {
+ // throw new IllegalStateException("No server found");
+ // }
+ //
+ // chosenServers.add(server);
+ // addedPlayerCount.put(
+ // server.getServerInfo().getName(),
+ // addedPlayerCount.getOrDefault(server.getServerInfo().getName(), 0) + 1);
+ // }
+ //
+ // return chosenServers;
+ // }
+}
diff --git a/src/main/java/net/azisaba/kuvel/loadbalancer/strategy/impl/RoundRobinLoadBalancingStrategy.java b/src/main/java/net/azisaba/kuvel/loadbalancer/strategy/impl/RoundRobinLoadBalancingStrategy.java
new file mode 100644
index 00000000..3b74490d
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/loadbalancer/strategy/impl/RoundRobinLoadBalancingStrategy.java
@@ -0,0 +1,34 @@
+package net.azisaba.kuvel.loadbalancer.strategy.impl;
+
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import java.util.List;
+import net.azisaba.kuvel.loadbalancer.LoadBalancingStrategy;
+
+public class RoundRobinLoadBalancingStrategy implements LoadBalancingStrategy {
+
+ private int lastIndex = 0;
+
+ @Override
+ public RegisteredServer choose(List servers) {
+ if (servers.isEmpty()) {
+ return null;
+ }
+
+ lastIndex++;
+ if (servers.size() <= lastIndex) {
+ lastIndex = 0;
+ return servers.get(0);
+ }
+ return servers.get(lastIndex);
+ }
+
+ // @Override
+ // public List choose(List servers, int count) {
+ // List chosenServers = new ArrayList<>();
+ // for (int i = 0; i < count; i++) {
+ // chosenServers.add(choose(servers));
+ // }
+ //
+ // return chosenServers;
+ // }
+}
diff --git a/src/main/java/net/azisaba/kuvel/redis/ProxyIdProvider.java b/src/main/java/net/azisaba/kuvel/redis/ProxyIdProvider.java
new file mode 100644
index 00000000..e5529173
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/redis/ProxyIdProvider.java
@@ -0,0 +1,59 @@
+package net.azisaba.kuvel.redis;
+
+import com.velocitypowered.api.proxy.ProxyServer;
+import java.util.concurrent.TimeUnit;
+import lombok.RequiredArgsConstructor;
+import org.apache.commons.lang3.RandomStringUtils;
+import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisPool;
+
+@RequiredArgsConstructor
+public class ProxyIdProvider {
+
+ private final JedisPool jedisPool;
+ private final String groupName;
+
+ private String id;
+
+ public String getId() {
+ if (id == null) {
+ String idTmp = RandomStringUtils.randomAlphanumeric(8);
+
+ try (Jedis jedis = jedisPool.getResource()) {
+ while (true) {
+ String key = RedisKeys.PROXY_ID_PREFIX.getKey() + groupName + ":" + idTmp;
+ long result = jedis.setnx(key, "true");
+
+ if (result == 1) {
+ jedis.expire(key, 600);
+ id = idTmp;
+ break;
+ }
+
+ idTmp = RandomStringUtils.randomAlphanumeric(8);
+ }
+ }
+ }
+ return id;
+ }
+
+ public void runTask(ProxyServer proxy, Object plugin) {
+ proxy
+ .getScheduler()
+ .buildTask(
+ plugin,
+ () -> {
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.expire(RedisKeys.PROXY_ID_PREFIX.getKey() + groupName + ":" + id, 600);
+ }
+ })
+ .repeat(5, TimeUnit.MINUTES)
+ .schedule();
+ }
+
+ public void deleteProxyId() {
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.del(RedisKeys.PROXY_ID_PREFIX.getKey() + groupName + ":" + id);
+ }
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/redis/RedisConnectionLeader.java b/src/main/java/net/azisaba/kuvel/redis/RedisConnectionLeader.java
new file mode 100644
index 00000000..fd1bffc2
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/redis/RedisConnectionLeader.java
@@ -0,0 +1,95 @@
+package net.azisaba.kuvel.redis;
+
+import java.util.Objects;
+import lombok.RequiredArgsConstructor;
+import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisPool;
+
+@RequiredArgsConstructor
+public class RedisConnectionLeader {
+
+ private final JedisPool jedisPool;
+ private final String groupName;
+ private final String proxyId;
+
+ private boolean leader = false;
+ private long leaderExpireAt = 0;
+
+ public boolean isLeader() {
+ if (leader && leaderExpireAt < System.currentTimeMillis()) {
+ leader = false;
+ }
+ return leader;
+ }
+
+ public boolean trySwitch() {
+ try (Jedis jedis = jedisPool.getResource()) {
+ String key = RedisKeys.LEADER_PREFIX.getKey() + groupName;
+ long result = jedis.setnx(key, proxyId);
+
+ if (result == 1) {
+ jedis.expire(key, 600);
+ leader = true;
+ leaderExpireAt = System.currentTimeMillis() + (600 * 1000);
+ return true;
+ } else {
+ String currentLeader = jedis.get(RedisKeys.LEADER_PREFIX.getKey() + groupName);
+ if (Objects.equals(proxyId, currentLeader)) {
+ leader = true;
+ return true;
+ }
+ return false;
+ }
+ }
+ }
+
+ public void extendLeader() {
+ if (!trySwitch()) {
+ return;
+ }
+
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.expire(RedisKeys.LEADER_PREFIX.getKey() + groupName, 600);
+ leaderExpireAt = System.currentTimeMillis() + (600 * 1000);
+ }
+ }
+
+ public void leaveLeader() {
+ try (Jedis jedis = jedisPool.getResource()) {
+ String currentLeader = jedis.get(RedisKeys.LEADER_PREFIX.getKey() + groupName);
+ if (!Objects.equals(proxyId, currentLeader)) {
+ return;
+ }
+
+ jedis.del(RedisKeys.LEADER_PREFIX.getKey() + groupName);
+ }
+ }
+
+ public void publishNewLoadBalancer(String replicaSetUid, String serverName) {
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.publish(
+ RedisKeys.LOAD_BALANCER_ADDED_NOTIFY_PREFIX.getKey() + groupName,
+ replicaSetUid + ":" + serverName);
+ }
+ }
+
+ public void publishNewServer(String podUid, String serverName) {
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.publish(
+ RedisKeys.POD_ADDED_NOTIFY_PREFIX.getKey() + groupName, podUid + ":" + serverName);
+ }
+ }
+
+ public void publishDeletedLoadBalancer(String replicaSetUid) {
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.publish(
+ RedisKeys.LOAD_BALANCER_DELETED_NOTIFY_PREFIX.getKey() + groupName, replicaSetUid);
+ }
+ }
+
+ public void publishDeletedServer(String podUid) {
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.publish(RedisKeys.POD_DELETED_NOTIFY_PREFIX.getKey() + groupName, podUid);
+ }
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/redis/RedisKeys.java b/src/main/java/net/azisaba/kuvel/redis/RedisKeys.java
new file mode 100644
index 00000000..90290eb8
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/redis/RedisKeys.java
@@ -0,0 +1,29 @@
+package net.azisaba.kuvel.redis;
+
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+public enum RedisKeys {
+ LEADER_PREFIX("kuvel:leader:"),
+ PROXY_ID_PREFIX("kuvel:proxy-id:"),
+ SERVERS_PREFIX("kuvel:servers:"),
+ LOAD_BALANCERS_PREFIX("kuvel:load-balancers:"),
+
+ NOTIFY_CHANNEL_PREFIX("kuvel:notify:"),
+ POD_ADDED_NOTIFY_PREFIX("kuvel:notify:add:pod:"),
+ LOAD_BALANCER_ADDED_NOTIFY_PREFIX("kuvel:notify:add:lb:"),
+ POD_DELETED_NOTIFY_PREFIX("kuvel:notify:del:pod:"),
+ LOAD_BALANCER_DELETED_NOTIFY_PREFIX("kuvel:notify:del:lb:");
+
+ private final String key;
+
+ public String getKey() {
+ return key;
+ }
+
+ @Override
+ public String toString() {
+ return getKey();
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/redis/RedisSubscriber.java b/src/main/java/net/azisaba/kuvel/redis/RedisSubscriber.java
new file mode 100644
index 00000000..3cd8a391
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/redis/RedisSubscriber.java
@@ -0,0 +1,100 @@
+package net.azisaba.kuvel.redis;
+
+import com.velocitypowered.api.proxy.server.RegisteredServer;
+import com.velocitypowered.api.proxy.server.ServerInfo;
+import java.net.InetSocketAddress;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import lombok.Setter;
+import net.azisaba.kuvel.Kuvel;
+import net.azisaba.kuvel.KuvelServiceHandler;
+import net.azisaba.kuvel.loadbalancer.LoadBalancer;
+import net.azisaba.kuvel.loadbalancer.strategy.impl.RoundRobinLoadBalancingStrategy;
+import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisPool;
+import redis.clients.jedis.JedisPubSub;
+
+@RequiredArgsConstructor
+public class RedisSubscriber {
+
+ private final JedisPool jedisPool;
+ private final Kuvel plugin;
+ private final String groupName;
+ private final KuvelServiceHandler handler;
+ private final RedisConnectionLeader redisConnectionLeader;
+
+ @Getter @Setter private ExecutorService executorService = Executors.newFixedThreadPool(1);
+
+ public void subscribe() {
+ JedisPubSub subscriber =
+ new JedisPubSub() {
+ @Override
+ public void onPMessage(String pattern, String channel, String message) {
+ if (redisConnectionLeader.isLeader()) {
+ return;
+ }
+
+ String receivedGroupName = channel.split(":")[channel.split(":").length - 1];
+ if (!receivedGroupName.equalsIgnoreCase(groupName)) {
+ return;
+ }
+
+ if (channel.startsWith(RedisKeys.POD_ADDED_NOTIFY_PREFIX.getKey())) {
+ String podUid = message.split(":")[0];
+ String serverName = message.split(":")[1];
+
+ handler.registerPod(podUid, serverName);
+ } else if (channel.startsWith(RedisKeys.LOAD_BALANCER_ADDED_NOTIFY_PREFIX.getKey())) {
+ String replicaSetUid = message.split(":")[0];
+ String serverName = message.split(":")[1];
+
+ RegisteredServer server =
+ plugin
+ .getProxy()
+ .registerServer(
+ new ServerInfo(serverName, new InetSocketAddress("0.0.0.0", 0)));
+ LoadBalancer loadBalancer =
+ new LoadBalancer(
+ plugin.getProxy(),
+ server,
+ new RoundRobinLoadBalancingStrategy(),
+ replicaSetUid);
+ handler.registerLoadBalancer(loadBalancer);
+ } else if (channel.startsWith(RedisKeys.POD_DELETED_NOTIFY_PREFIX.getKey())) {
+ handler.unregisterPod(message);
+ } else if (channel.startsWith(RedisKeys.LOAD_BALANCER_DELETED_NOTIFY_PREFIX.getKey())) {
+ handler.unregisterLoadBalancer(message);
+ }
+ }
+ };
+
+ Runnable task =
+ () -> {
+ try (Jedis jedis = jedisPool.getResource()) {
+ jedis.psubscribe(
+ subscriber, RedisKeys.NOTIFY_CHANNEL_PREFIX.getKey() + "*:" + groupName);
+ }
+ };
+
+ runsOnExecutor(executorService, task);
+ }
+
+ public void runsOnExecutor(ExecutorService executor, Runnable runnable) {
+ executor.submit(runnable);
+
+ for (int i = 0; i < 1000; i++) {
+ executor.submit(
+ () -> {
+ try {
+ Thread.sleep(3000);
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ }
+
+ runnable.run();
+ });
+ }
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/util/LabelKeys.java b/src/main/java/net/azisaba/kuvel/util/LabelKeys.java
new file mode 100644
index 00000000..e3a20c9d
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/util/LabelKeys.java
@@ -0,0 +1,18 @@
+package net.azisaba.kuvel.util;
+
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+public enum LabelKeys {
+ SERVER_DISCOVERY("minecraftServiceDiscovery"),
+ SERVER_NAME("minecraftServerName");
+
+ @Getter private final String key;
+
+ @Override
+ public String toString() {
+ return getKey();
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/util/RedisConnectionData.java b/src/main/java/net/azisaba/kuvel/util/RedisConnectionData.java
new file mode 100644
index 00000000..e3f23e13
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/util/RedisConnectionData.java
@@ -0,0 +1,51 @@
+package net.azisaba.kuvel.util;
+
+import java.util.Objects;
+import lombok.Data;
+import redis.clients.jedis.JedisPool;
+import redis.clients.jedis.JedisPoolConfig;
+
+@Data
+public class RedisConnectionData {
+
+ private final String hostname;
+ private final int port;
+
+ private final String username;
+ private final String password;
+
+ public RedisConnectionData(String hostname, int port, String username, String password) {
+ if (Objects.equals(username, "")) {
+ username = null;
+ }
+ if (Objects.equals(password, "")) {
+ password = null;
+ }
+
+ this.hostname = hostname;
+ this.port = port;
+ this.username = username;
+ this.password = password;
+ }
+
+ public RedisConnectionData(String hostname, int port) {
+ this(hostname, port, null, null);
+ }
+
+ public RedisConnectionData(String hostname, int port, String password) {
+ this(hostname, port, null, password);
+ }
+
+ public JedisPool createJedisPool() {
+ if (username != null && password != null) {
+ return new JedisPool(hostname, port, username, password);
+ } else if (password != null) {
+ return new JedisPool(new JedisPoolConfig(), hostname, port, 3000, password);
+ } else if (username != null) {
+ throw new IllegalArgumentException(
+ "Redis password cannot be null if redis username is not null");
+ } else {
+ return new JedisPool(new JedisPoolConfig(), hostname, port);
+ }
+ }
+}
diff --git a/src/main/java/net/azisaba/kuvel/util/UidAndServerNameMap.java b/src/main/java/net/azisaba/kuvel/util/UidAndServerNameMap.java
new file mode 100644
index 00000000..3af56da6
--- /dev/null
+++ b/src/main/java/net/azisaba/kuvel/util/UidAndServerNameMap.java
@@ -0,0 +1,34 @@
+package net.azisaba.kuvel.util;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class UidAndServerNameMap {
+
+ private final HashMap uidToServerName = new HashMap<>();
+
+ public String getServerNameFromUid(String podUid) {
+ return uidToServerName.get(podUid);
+ }
+
+ public String getUidFromServerName(String serverName) {
+ for (String podUid : uidToServerName.keySet()) {
+ if (uidToServerName.get(podUid).equals(serverName)) {
+ return podUid;
+ }
+ }
+ return null;
+ }
+
+ public Map getAllMap() {
+ return new HashMap<>(uidToServerName);
+ }
+
+ public void register(String uid, String serverName) {
+ uidToServerName.put(uid, serverName);
+ }
+
+ public String unregister(String uid) {
+ return uidToServerName.remove(uid);
+ }
+}
diff --git a/src/main/resources/config.yml b/src/main/resources/config.yml
new file mode 100644
index 00000000..7bc716d6
--- /dev/null
+++ b/src/main/resources/config.yml
@@ -0,0 +1,11 @@
+# Server name synchronization by Redis is required in load-balanced environments using multiple Velocity.
+redis:
+ enable: false
+ group-name: "production"
+ connection:
+ hostname: "localhost"
+ port: 6379
+ # username is optional. if you have authentication enabled, you can use it here. Or leave it blank or null.
+ username: "root"
+ # password is optional. if you have authentication enabled, you can use it here. Or leave it blank or null.
+ password: "password"
\ No newline at end of file