Update command #539

Plan/src/main/java/com/djrapitops/plan/command/PlanBungeeCommand.java

@@ -4,6 +4,7 @@ import com.djrapitops.plan.PlanBungee;
 import com.djrapitops.plan.command.commands.*;
 import com.djrapitops.plan.command.commands.manage.ManageConDebugCommand;
 import com.djrapitops.plan.system.settings.Permissions;
+import com.djrapitops.plan.system.settings.Settings;
 import com.djrapitops.plan.system.settings.locale.Locale;
 import com.djrapitops.plan.system.settings.locale.Msg;
 import com.djrapitops.plugin.command.CommandNode;
@@ -49,6 +50,7 @@ public class PlanBungeeCommand extends TreeCmdNode {
                         new BungeeSetupToggleCommand(),
                         new ReloadCommand(plugin),
                         new StatusCommand<>(plugin, Permissions.MANAGE.getPermission(), plugin.getColorScheme()),
+                        (Settings.ALLOW_UPDATE.isTrue() ? new UpdateCommand() : null)
                 }
         );
     }

Plan/src/main/java/com/djrapitops/plan/command/PlanCommand.java

@@ -46,7 +46,8 @@ public class PlanCommand extends TreeCmdNode {
                         new ReloadCommand(plugin),
                         new ManageCommand(plugin, this),
                         new StatusCommand<>(plugin, Permissions.MANAGE.getPermission(), plugin.getColorScheme()),
-                        (Settings.DEV_MODE.isTrue() ? new DevCommand() : null)
+                        (Settings.DEV_MODE.isTrue() ? new DevCommand() : null),
+                        (Settings.ALLOW_UPDATE.isTrue() ? new UpdateCommand() : null)
                 }
         );
     }

Plan/src/main/java/com/djrapitops/plan/command/commands/UpdateCommand.java

@@ -0,0 +1,210 @@
+package com.djrapitops.plan.command.commands;
+
+import com.djrapitops.plan.api.exceptions.connection.*;
+import com.djrapitops.plan.api.exceptions.database.DBException;
+import com.djrapitops.plan.command.commands.manage.ManageConDebugCommand;
+import com.djrapitops.plan.system.database.databases.Database;
+import com.djrapitops.plan.system.database.databases.operation.FetchOperations;
+import com.djrapitops.plan.system.info.InfoSystem;
+import com.djrapitops.plan.system.info.request.CheckConnectionRequest;
+import com.djrapitops.plan.system.info.request.UpdateCancelRequest;
+import com.djrapitops.plan.system.info.server.Server;
+import com.djrapitops.plan.system.settings.Permissions;
+import com.djrapitops.plan.system.update.VersionCheckSystem;
+import com.djrapitops.plan.system.update.VersionInfo;
+import com.djrapitops.plan.system.webserver.WebServerSystem;
+import com.djrapitops.plugin.api.utility.log.Log;
+import com.djrapitops.plugin.command.CommandNode;
+import com.djrapitops.plugin.command.CommandType;
+import com.djrapitops.plugin.command.ISender;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.UUID;
+
+/**
+ * Command that updates all servers in the network
+ *
+ * @author Rsl1122
+ */
+public class UpdateCommand extends CommandNode {
+
+    public UpdateCommand() {
+        super("update", Permissions.MANAGE.getPermission(), CommandType.ALL);
+        setArguments("[-update]/[cancel]");
+        setShortHelp("Get change log link or update plugin.");
+        setInDepthHelp(
+                "/plan update",
+                "  Used to update the plugin on the next shutdown\n",
+                "  /plan update - get change log link",
+                "  /plan update -update - Schedule update to happen on all network servers that are online next time they reboot.",
+                "  /plan update cancel - Cancel scheduled update on servers that haven't rebooted yet."
+        );
+    }
+
+    @Override
+    public void onCommand(ISender sender, String commandLabel, String[] args) {
+        if (!VersionCheckSystem.isNewVersionAvailable()) {
+            sender.sendMessage("§aYou're running the latest version of Plan.");
+            return;
+        }
+
+        VersionInfo available = VersionCheckSystem.getInstance().getNewVersionAvailable();
+        String downloadUrl = available.getDownloadUrl();
+
+        if (!available.isTrusted()) {
+            sender.sendMessage("§cVersion download url did not start with " +
+                    "https://github.com/Rsl1122/Plan-PlayerAnalytics/releases/ " +
+                    "and might not be trusted. You can download this version manually here (Direct download):");
+            sender.sendLink(downloadUrl, downloadUrl);
+            return;
+        }
+
+        if (args.length == 0) {
+            sender.sendLink("Change Log v" + available.getVersion().toString() + ": ", "Click me", available.getChangeLogUrl());
+            return;
+        }
+
+        String firstArgument = args[0];
+        if ("-update".equals(firstArgument)) {
+            handleUpdate(sender, args);
+        } else if ("cancel".equals(firstArgument)) {
+            cancel(sender);
+        } else {
+            throw new IllegalArgumentException("Unknown argument, use '-update' or 'cancel'");
+        }
+    }
+
+    private void cancel(ISender sender) {
+        try {
+            cancel(sender, Database.getActive().fetch().getServers());
+            sender.sendMessage("§aUpdate has been cancelled.");
+        } catch (DBException e) {
+            sender.sendMessage("§cDatabase error occurred, cancel could not be performed.");
+            Log.toLog(this.getClass().getName(), e);
+        }
+    }
+
+    private void handleUpdate(ISender sender, String[] args) {
+        sender.sendMessage("§aYou can cancel the update on servers that haven't rebooted yet with /plan update cancel.");
+        sender.sendMessage("Checking that all servers are online..");
+        if (!checkNetworkStatus(sender)) {
+            sender.sendMessage("§cNot all servers were online or accessible, you can still update available servers using -force as a 2nd argument.");
+            if (args.length <= 1 || !"-force".equals(args[1])) {
+                return;
+            }
+        }
+        try {
+            List<Server> servers = Database.getActive().fetch().getServers();
+            update(sender, servers);
+        } catch (DBException e) {
+            Log.toLog(this.getClass().getName(), e);
+        }
+    }
+
+    private void update(ISender sender, List<Server> servers) {
+        for (Server server : servers) {
+            if (update(sender, server)) {
+                sender.sendMessage("§a" + server.getName() + " scheduled for update.");
+            } else {
+                sender.sendMessage("§cUpdate failed on a server, cancelling update on all servers..");
+                cancel(sender, servers);
+                sender.sendMessage("§cUpdate cancelled.");
+                break;
+            }
+        }
+    }
+
+    private void cancel(ISender sender, List<Server> servers) {
+        for (Server server : servers) {
+            cancel(sender, server);
+        }
+
+    }
+
+    private void cancel(ISender sender, Server server) {
+        try {
+            InfoSystem.getInstance().getConnectionSystem().sendInfoRequest(new UpdateCancelRequest(), server);
+        } catch (ForbiddenException | GatewayException | InternalErrorException e) {
+            sender.sendMessage("§cCancel failed on " + server.getName() + ": Odd Exception: " + e.getClass().getSimpleName());
+        } catch (UnauthorizedServerException e) {
+            sender.sendMessage("§cCancel failed on " + server.getName() + ": Unauthorized. " + server.getName() + " might be using different database.");
+        } catch (ConnectionFailException e) {
+            sender.sendMessage("§cCancel failed on " + server.getName() + ": " + e.getCause().getClass().getSimpleName() + " " + e.getCause().getMessage());
+            String address = server.getWebAddress();
+            boolean local = address.contains("localhost")
+                    || address.startsWith("https://:") // IP empty = Localhost
+                    || address.startsWith("http://:") // IP empty = Localhost
+                    || address.contains("127.0.0.1");
+            if (!local) {
+                sender.sendMessage("§cNon-local address, check that port is open");
+            }
+        } catch (NotFoundException e) {
+            /* Ignored, older version */
+        } catch (WebException e) {
+            sender.sendMessage("§cCancel failed on " + server.getName() + ": Odd Exception:" + e.getClass().getSimpleName());
+        }
+    }
+
+    private boolean update(ISender sender, Server server) {
+        try {
+            InfoSystem.getInstance().getConnectionSystem().sendInfoRequest(new CheckConnectionRequest(), server);
+            return true;
+        } catch (BadRequestException e) {
+            sender.sendMessage("§c" + server.getName() + " has Allow-Update set to false, aborting update.");
+            return false;
+        } catch (ForbiddenException | GatewayException | InternalErrorException e) {
+            sender.sendMessage("§c" + server.getName() + ": Odd Exception: " + e.getClass().getSimpleName());
+            return false;
+        } catch (UnauthorizedServerException e) {
+            sender.sendMessage("§cFail reason: Unauthorized. " + server.getName() + " might be using different database.");
+            return false;
+        } catch (ConnectionFailException e) {
+            sender.sendMessage("§cFail reason: " + e.getCause().getClass().getSimpleName() + " " + e.getCause().getMessage());
+            String address = server.getWebAddress();
+            boolean local = address.contains("localhost")
+                    || address.startsWith("https://:") // IP empty = Localhost
+                    || address.startsWith("http://:") // IP empty = Localhost
+                    || address.contains("127.0.0.1");
+            if (!local) {
+                sender.sendMessage("§cNon-local address, check that port is open");
+            }
+            return false;
+        } catch (NotFoundException e) {
+            sender.sendMessage("§e" + server.getName() + " is using older version and can not be scheduled for update. " +
+                    "You can update it manually, update will proceed.");
+            return true;
+        } catch (WebException e) {
+            sender.sendMessage("§eOdd Exception: " + e.getClass().getSimpleName());
+            return false;
+        }
+    }
+
+    private boolean checkNetworkStatus(ISender sender) {
+        try {
+            FetchOperations fetch = Database.getActive().fetch();
+            Optional<Server> bungeeInformation = fetch.getBungeeInformation();
+            if (!bungeeInformation.isPresent()) {
+                return true;
+            }
+            Map<UUID, Server> bukkitServers = fetch.getBukkitServers();
+            String accessAddress = WebServerSystem.getInstance().getWebServer().getAccessAddress();
+            boolean success = true;
+            for (Server server : bukkitServers.values()) {
+                if (!ManageConDebugCommand.testServer(sender, accessAddress, server)) {
+                    success = false;
+                }
+            }
+            Server bungee = bungeeInformation.get();
+            if (!ManageConDebugCommand.testServer(sender, accessAddress, bungee)) {
+                success = false;
+            }
+            return success;
+        } catch (DBException e) {
+            sender.sendMessage("§cDatabase error occurred, update has been cancelled.");
+            Log.toLog(this.getClass().getName(), e);
+            return false;
+        }
+    }
+}

Plan/src/main/java/com/djrapitops/plan/command/commands/manage/ManageConDebugCommand.java

@@ -28,12 +28,9 @@ import java.util.UUID;
  */
 public class ManageConDebugCommand extends CommandNode {
 
-    private final ColorScheme cs;
-
     public ManageConDebugCommand() {
         super("con", Permissions.MANAGE.getPermission(), CommandType.ALL);
         setShortHelp("Debug Bukkit-Bungee Connections");
-        cs = PlanPlugin.getInstance().getColorScheme();
     }
 
     @Override
@@ -68,18 +65,19 @@ public class ManageConDebugCommand extends CommandNode {
         }
     }
 
-    private void testServer(ISender sender, String accessAddress, Server server) {
+    public static boolean testServer(ISender sender, String accessAddress, Server server) {
         String address = server.getWebAddress().toLowerCase();
         boolean usingHttps = address.startsWith("https");
         boolean local = address.contains("localhost")
-                || address.startsWith("https://:")
-                || address.startsWith("http://:")
+                || address.startsWith("https://:") // IP empty = Localhost
+                || address.startsWith("http://:") // IP empty = Localhost
                 || address.contains("127.0.0.1");
 
         try {
 
             InfoSystem.getInstance().getConnectionSystem().sendInfoRequest(new CheckConnectionRequest(accessAddress), server);
             sender.sendMessage(getMsgFor(address, usingHttps, local, true, true));
+            return true;
 
         } catch (ForbiddenException | BadRequestException | InternalErrorException e) {
             sender.sendMessage(getMsgFor(address, usingHttps, local, false, false));
@@ -102,9 +100,11 @@ public class ManageConDebugCommand extends CommandNode {
             sender.sendMessage(getMsgFor(address, usingHttps, local, false, false));
             sender.sendMessage("§eOdd Exception: " + e.getClass().getSimpleName());
         }
+        return false;
     }
 
-    private String getMsgFor(String address, boolean usingHttps, boolean local, boolean successTo, boolean successFrom) {
+    private static String getMsgFor(String address, boolean usingHttps, boolean local, boolean successTo, boolean successFrom) {
+        ColorScheme cs = PlanPlugin.getInstance().getColorScheme();
         String tCol = cs.getTertiaryColor();
         String sCol = cs.getSecondaryColor();
         return tCol + address + sCol + ": "

Plan/src/main/java/com/djrapitops/plan/system/info/connection/ConnectionSystem.java

@@ -125,6 +125,9 @@ public abstract class ConnectionSystem implements SubSystem {
         putRequest(requests, SaveDBSettingsRequest.createHandler());
         putRequest(requests, SendDBSettingsRequest.createHandler());
         putRequest(requests, CheckConnectionRequest.createHandler());
+
+        putRequest(requests, UpdateRequest.createHandler());
+        putRequest(requests, UpdateCancelRequest.createHandler());
         return requests;
     }
 

Plan/src/main/java/com/djrapitops/plan/system/info/request/UpdateCancelRequest.java

@@ -0,0 +1,37 @@
+/*
+ * Licence is provided in the jar as license.yml also here:
+ * https://github.com/Rsl1122/Plan-PlayerAnalytics/blob/master/Plan/src/main/resources/license.yml
+ */
+package com.djrapitops.plan.system.info.request;
+
+import com.djrapitops.plan.system.update.ShutdownUpdateHook;
+import com.djrapitops.plan.system.webserver.response.DefaultResponses;
+import com.djrapitops.plan.system.webserver.response.Response;
+
+import java.util.Map;
+
+/**
+ * InfoRequest used for Updating the plugin on a network.
+ *
+ * @author Rsl1122
+ */
+public class UpdateCancelRequest implements InfoRequest {
+
+    public UpdateCancelRequest() {
+    }
+
+    public static UpdateCancelRequest createHandler() {
+        return new UpdateCancelRequest();
+    }
+
+    @Override
+    public void runLocally() {
+        ShutdownUpdateHook.deActivate();
+    }
+
+    @Override
+    public Response handleRequest(Map<String, String> variables) {
+        ShutdownUpdateHook.deActivate();
+        return DefaultResponses.SUCCESS.get();
+    }
+}

Plan/src/main/java/com/djrapitops/plan/system/info/request/UpdateRequest.java

@@ -0,0 +1,43 @@
+/*
+ * Licence is provided in the jar as license.yml also here:
+ * https://github.com/Rsl1122/Plan-PlayerAnalytics/blob/master/Plan/src/main/resources/license.yml
+ */
+package com.djrapitops.plan.system.info.request;
+
+import com.djrapitops.plan.system.settings.Settings;
+import com.djrapitops.plan.system.update.ShutdownUpdateHook;
+import com.djrapitops.plan.system.webserver.response.DefaultResponses;
+import com.djrapitops.plan.system.webserver.response.Response;
+import com.djrapitops.plan.system.webserver.response.api.BadRequestResponse;
+
+import java.util.Map;
+
+/**
+ * InfoRequest used for Updating the plugin on a network.
+ *
+ * @author Rsl1122
+ */
+public class UpdateRequest implements InfoRequest {
+
+    public UpdateRequest() {
+    }
+
+    public static UpdateRequest createHandler() {
+        return new UpdateRequest();
+    }
+
+    @Override
+    public void runLocally() {
+        new ShutdownUpdateHook().register();
+    }
+
+    @Override
+    public Response handleRequest(Map<String, String> variables) {
+        if (Settings.ALLOW_UPDATE.isTrue()) {
+            new ShutdownUpdateHook().register();
+            return DefaultResponses.SUCCESS.get();
+        } else {
+            return new BadRequestResponse("Update not allowed on this server");
+        }
+    }
+}

Plan/src/main/java/com/djrapitops/plan/system/settings/Settings.java

@@ -37,6 +37,8 @@ public enum Settings {
     DISPLAY_PLAYER_IPS("Customization.Display.PlayerIPs"),
     DISPLAY_GAPS_IN_GRAPH_DATA("Customization.Display.GapsInGraphData"),
     DATA_GEOLOCATIONS("Data.Geolocations"),
+    ALLOW_UPDATE("Plugin.Allow-Update-Command"),
+    NOTIFY_ABOUT_DEV_RELEASES("Plugin.Notify-About-DEV-Releases"),
 
     // Integer
     WEBSERVER_PORT("WebServer.Port"),

Plan/src/main/java/com/djrapitops/plan/system/update/ShutdownUpdateHook.java

@@ -0,0 +1,104 @@
+package com.djrapitops.plan.system.update;
+
+import com.djrapitops.plan.PlanPlugin;
+import com.djrapitops.plugin.api.Check;
+import com.djrapitops.plugin.api.utility.Version;
+import com.djrapitops.plugin.api.utility.log.Log;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.net.URL;
+import java.nio.channels.Channels;
+import java.nio.channels.ReadableByteChannel;
+
+/**
+ * Shutdown hook that updates the plugin on server shutdown.
+ * <p>
+ * Does not perform update on force close.
+ *
+ * @author Rsl1122
+ */
+public class ShutdownUpdateHook extends Thread {
+
+    private static boolean activated = false;
+
+    private static boolean isActivated() {
+        return activated;
+    }
+
+    private static void activate(ShutdownUpdateHook hook) {
+        activated = true;
+        Runtime.getRuntime().addShutdownHook(hook);
+    }
+
+    public static void deActivate() {
+        activated = false;
+        Log.infoColor("§aUpdate has been cancelled.");
+    }
+
+    public void register() {
+        if (isActivated()) {
+            return;
+        }
+        Log.infoColor("§aUpdate has been scheduled, The new jar will be downloaded on server shutdown.");
+        activate(this);
+    }
+
+    @Override
+    public void run() {
+        if (!activated) {
+            return;
+        }
+        activated = false;
+        VersionInfo available = VersionCheckSystem.getInstance().getNewVersionAvailable();
+
+        if (!Version.isNewVersionAvailable(new Version(VersionCheckSystem.getCurrentVersion()), available.getVersion())) {
+            return;
+        }
+
+        File dataFolder = PlanPlugin.getInstance().getDataFolder();
+        File pluginsFolder = Check.isSpongeAvailable()
+                ? dataFolder.getParentFile()
+                : new File(dataFolder.getParentFile().getParentFile(), "mods");
+        if (pluginsFolder == null || !pluginsFolder.isDirectory()) {
+            System.out.println("Could not get plugin folder for Plan.");
+            return;
+        }
+        File newFileLocation = new File(pluginsFolder, "Plan-" + available.getVersion() + ".jar");
+
+        try {
+            downloadNewJar(available, newFileLocation);
+            deleteOldJar(pluginsFolder, newFileLocation);
+        } catch (IOException e) {
+            Log.toLog(this.getClass().getName(), e);
+        }
+    }
+
+    private void deleteOldJar(File pluginsFolder, File newFileLocation) {
+        File[] files = pluginsFolder.listFiles();
+        if (files == null) {
+            System.out.println("Could not delete old jar.");
+            return;
+        }
+        for (File file : files) {
+            String fileName = file.getName();
+            boolean isPlanJar = (fileName.startsWith("Plan-")
+                    && fileName.endsWith(".jar"))
+                    || fileName.equals("Plan.jar");
+            boolean isNewJar = fileName.equals(newFileLocation.getName());
+            if (isPlanJar && !isNewJar) {
+                file.deleteOnExit();
+            }
+        }
+    }
+
+    private void downloadNewJar(VersionInfo available, File newFileLocation) throws IOException {
+        URL downloadFrom = new URL(available.getDownloadUrl());
+
+        ReadableByteChannel rbc = Channels.newChannel(downloadFrom.openStream());
+        FileOutputStream fos = new FileOutputStream(newFileLocation);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+    }
+
+}

Plan/src/main/java/com/djrapitops/plan/system/update/VersionCheckSystem.java

@@ -6,6 +6,7 @@ package com.djrapitops.plan.system.update;
 
 import com.djrapitops.plan.system.PlanSystem;
 import com.djrapitops.plan.system.SubSystem;
+import com.djrapitops.plan.system.settings.Settings;
 import com.djrapitops.plugin.api.Priority;
 import com.djrapitops.plugin.api.systems.NotificationCenter;
 import com.djrapitops.plugin.api.utility.Version;
@@ -13,6 +14,8 @@ import com.djrapitops.plugin.api.utility.log.Log;
 import com.djrapitops.plugin.utilities.Verify;
 
 import java.io.IOException;
+import java.util.List;
+import java.util.stream.Collectors;
 
 /**
  * System for checking if new Version is available when the System initializes.
@@ -22,7 +25,7 @@ import java.io.IOException;
 public class VersionCheckSystem implements SubSystem {
 
     private final String currentVersion;
-    private boolean newVersionAvailable = false;
+    private VersionInfo newVersionAvailable;
 
     public VersionCheckSystem(String currentVersion) {
         this.currentVersion = currentVersion;
@@ -35,7 +38,7 @@ public class VersionCheckSystem implements SubSystem {
     }
 
     public static boolean isNewVersionAvailable() {
-        return getInstance().newVersionAvailable;
+        return getInstance().newVersionAvailable != null;
     }
 
     public static String getCurrentVersion() {
@@ -44,14 +47,35 @@ public class VersionCheckSystem implements SubSystem {
 
     @Override
     public void enable() {
-        checkForNewVersion();
+        if (Settings.ALLOW_UPDATE.isTrue()) {
+            try {
+                List<VersionInfo> versions = VersionInfoLoader.load();
+                if (Settings.NOTIFY_ABOUT_DEV_RELEASES.isFalse()) {
+                    versions = versions.stream().filter(VersionInfo::isRelease).collect(Collectors.toList());
+                }
+                VersionInfo newestVersion = versions.get(0);
+                if (Version.isNewVersionAvailable(new Version(currentVersion), newestVersion.getVersion())) {
+                    String notification =
+                            "New Release (" + newestVersion.getVersion().toString() + ") is available and can be updated " +
+                                    "to using update subcommand." + (newestVersion.isRelease() ? "" : " This is a DEV release.");
+                    Log.info(notification);
+                    NotificationCenter.addNotification(newestVersion.isRelease() ? Priority.HIGH : Priority.MEDIUM, notification);
+                } else {
+                    Log.info("You're using the latest version.");
+                }
+            } catch (IOException e) {
+                Log.error("Version information could not be loaded from Github/versions.txt");
+            }
+        } else {
+            checkForNewVersion();
+        }
     }
 
     private void checkForNewVersion() {
         String githubVersionUrl = "https://raw.githubusercontent.com/Rsl1122/Plan-PlayerAnalytics/master/Plan/src/main/resources/plugin.yml";
         String spigotUrl = "https://www.spigotmc.org/resources/plan-player-analytics.32536/";
         try {
-            newVersionAvailable = Version.checkVersion(currentVersion, githubVersionUrl);
+            boolean newVersionAvailable = Version.checkVersion(currentVersion, githubVersionUrl);
             if (!newVersionAvailable) {
                 try {
                     newVersionAvailable = Version.checkVersion(currentVersion, spigotUrl);
@@ -77,4 +101,8 @@ public class VersionCheckSystem implements SubSystem {
     public void disable() {
         /* Does not need to be closed */
     }
+
+    public VersionInfo getNewVersionAvailable() {
+        return newVersionAvailable;
+    }
 }

Plan/src/main/java/com/djrapitops/plan/system/update/VersionInfo.java

@@ -0,0 +1,63 @@
+package com.djrapitops.plan.system.update;
+
+import com.djrapitops.plugin.api.utility.Version;
+import com.google.common.base.Objects;
+
+/**
+ * Data class for reading version.txt in https://github.com/Rsl1122/Plan-PlayerAnalytics.
+ *
+ * @author Rsl1122
+ */
+public class VersionInfo implements Comparable<VersionInfo> {
+
+    private final boolean release;
+    private final Version version;
+    private final String downloadUrl;
+    private final String changeLogUrl;
+
+    public VersionInfo(boolean release, Version version, String downloadUrl, String changeLogUrl) {
+        this.release = release;
+        this.version = version;
+        this.downloadUrl = downloadUrl;
+        this.changeLogUrl = changeLogUrl;
+    }
+
+    public boolean isRelease() {
+        return release;
+    }
+
+    public Version getVersion() {
+        return version;
+    }
+
+    public String getDownloadUrl() {
+        return downloadUrl;
+    }
+
+    public String getChangeLogUrl() {
+        return changeLogUrl;
+    }
+
+    public boolean isTrusted() {
+        return downloadUrl.startsWith("https://github.com/Rsl1122/Plan-PlayerAnalytics/releases/download/");
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        VersionInfo that = (VersionInfo) o;
+        return release == that.release &&
+                Objects.equal(version, that.version);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hashCode(release, version);
+    }
+
+    @Override
+    public int compareTo(VersionInfo o) {
+        return -this.version.compareTo(o.version);
+    }
+}

Plan/src/main/java/com/djrapitops/plan/system/update/VersionInfoLoader.java

@@ -0,0 +1,57 @@
+package com.djrapitops.plan.system.update;
+
+import com.djrapitops.plugin.api.utility.Version;
+
+import java.io.IOException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Scanner;
+
+/**
+ * Utility for loading version information from github.
+ *
+ * @author Rsl1122
+ */
+public class VersionInfoLoader {
+
+    private static final String VERSION_TXT_URL =
+            "https://raw.githubusercontent.com/Rsl1122/Plan-PlayerAnalytics/master/versions.txt";
+
+    /**
+     * Loads version information from github.
+     *
+     * @return List of VersionInfo, newest version first.
+     * @throws IOException                    If site can not be accessed.
+     * @throws java.net.MalformedURLException If VERSION_TXT_URL is not valid.
+     */
+    public static List<VersionInfo> load() throws IOException {
+        URL url = new URL(VERSION_TXT_URL);
+
+        List<VersionInfo> versionInfo = new ArrayList<>();
+
+        try (Scanner websiteScanner = new Scanner(url.openStream())) {
+            while (websiteScanner.hasNextLine()) {
+                String line = websiteScanner.nextLine();
+                if (!line.startsWith("REL") && !line.startsWith("DEV")) {
+                    continue;
+                }
+                String[] parts = line.split("\\|");
+                if (parts.length < 4) {
+                    continue;
+                }
+                boolean release = parts[0].equals("REL");
+                Version version = new Version(parts[1]);
+                String downloadUrl = parts[2];
+                String changeLogUrl = parts[3];
+
+                versionInfo.add(new VersionInfo(release, version, downloadUrl, changeLogUrl));
+            }
+        }
+
+        Collections.sort(versionInfo);
+        return versionInfo;
+    }
+
+}

Plan/src/main/resources/bungee.yml

@@ -1,4 +1,4 @@
 name: Plan
 author: Rsl1122
 main: com.djrapitops.plan.PlanBungee
-version: 4.2.0
+version: 4.2.0-b1

Plan/src/main/resources/bungeeconfig.yml

@@ -12,6 +12,8 @@ Network:
 Plugin:
   Debug: 'false'
   Locale: default
+  Allow-Update-Command: true
+  Notify-About-DEV-Releases: false
 
 # -----------------------------------------------------
 # More information about SSL Certificate Settings:

Plan/src/main/resources/config.yml

@@ -17,6 +17,8 @@ Plugin:
   Bungee-Override:
     StandaloneMode: false
     CopyBungeeConfig: true
+  Allow-Update-Command: true
+  Notify-About-DEV-Releases: false
 
 # -----------------------------------------------------
 # More information about SSL Certificate Settings:

Plan/src/main/resources/plugin.yml

@@ -1,7 +1,7 @@
 name: Plan
 author: Rsl1122
 main: com.djrapitops.plan.Plan
-version: 4.2.0
+version: 4.2.0-b1
 softdepend:
 - EssentialsX
 - Towny

Plan/src/test/java/com/djrapitops/plan/system/update/VersionInfoLoaderTest.java

@@ -0,0 +1,24 @@
+package com.djrapitops.plan.system.update;
+
+import com.djrapitops.plugin.api.utility.Version;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class VersionInfoLoaderTest {
+
+    @Test
+    public void versionLoaderTest() throws IOException {
+        List<VersionInfo> versions = VersionInfoLoader.load();
+
+        VersionInfo oldest = versions.get(versions.size() - 1);
+        assertEquals(new Version("4.1.7"), oldest.getVersion());
+        assertTrue(oldest.isRelease());
+        assertTrue(oldest.isTrusted());
+    }
+
+}