Block creation of backups if it would put the server over it's limit

app/Exceptions/Service/Backup/TooManyBackupsException.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Pterodactyl\Exceptions\Service\Backup;
+
+use Pterodactyl\Exceptions\DisplayException;
+
+class TooManyBackupsException extends DisplayException
+{
+    /**
+     * TooManyBackupsException constructor.
+     *
+     * @param int $backupLimit
+     */
+    public function __construct(int $backupLimit)
+    {
+        parent::__construct(
+            sprintf('Cannot create a new backup, this server has reached its limit of %d backups.', $backupLimit)
+        );
+    }
+}

app/Services/Backups/InitiateBackupService.php

@@ -11,6 +11,7 @@ use Pterodactyl\Models\Server;
 use Illuminate\Database\ConnectionInterface;
 use Pterodactyl\Repositories\Eloquent\BackupRepository;
 use Pterodactyl\Repositories\Wings\DaemonBackupRepository;
+use Pterodactyl\Exceptions\Service\Backup\TooManyBackupsException;
 use Symfony\Component\HttpKernel\Exception\TooManyRequestsHttpException;
 
 class InitiateBackupService
@@ -84,9 +85,16 @@ class InitiateBackupService
      * @return \Pterodactyl\Models\Backup
      *
      * @throws \Throwable
+     * @throws \Pterodactyl\Exceptions\Service\Backup\TooManyBackupsException
+     * @throws \Symfony\Component\HttpKernel\Exception\TooManyRequestsHttpException
      */
     public function handle(Server $server, string $name = null): Backup
     {
+        // Do not allow the user to continue if this server is already at its limit.
+        if (! $server->backup_limit || $server->backups()->count() >= $server->backup_limit) {
+            throw new TooManyBackupsException($server->backup_limit);
+        }
+
         $previous = $this->repository->getBackupsGeneratedDuringTimespan($server->id, 10);
         if ($previous->count() >= 2) {
             throw new TooManyRequestsHttpException(