Improve logic handle auto-allocation of ports for a server

app/Services/Allocations/FindAssignableAllocationService.php

@@ -0,0 +1,130 @@
+<?php
+
+namespace Pterodactyl\Services\Allocations;
+
+use Webmozart\Assert\Assert;
+use Pterodactyl\Models\Server;
+use Pterodactyl\Models\Allocation;
+use Pterodactyl\Exceptions\DisplayException;
+use Pterodactyl\Exceptions\Service\Allocation\AutoAllocationNotEnabledException;
+use Pterodactyl\Exceptions\Service\Allocation\NoAutoAllocationSpaceAvailableException;
+
+class FindAssignableAllocationService
+{
+    /**
+     * @var \Pterodactyl\Services\Allocations\AssignmentService
+     */
+    private $service;
+
+    /**
+     * FindAssignableAllocationService constructor.
+     *
+     * @param \Pterodactyl\Services\Allocations\AssignmentService $service
+     */
+    public function __construct(AssignmentService $service)
+    {
+        $this->service = $service;
+    }
+
+    /**
+     * Finds an existing unassigned allocation and attempts to assign it to the given server. If
+     * no allocation can be found, a new one will be created with a random port between the defined
+     * range from the configuration.
+     *
+     * @param \Pterodactyl\Models\Server $server
+     * @return \Pterodactyl\Models\Allocation
+     *
+     * @throws \Pterodactyl\Exceptions\DisplayException
+     * @throws \Pterodactyl\Exceptions\Service\Allocation\CidrOutOfRangeException
+     * @throws \Pterodactyl\Exceptions\Service\Allocation\InvalidPortMappingException
+     * @throws \Pterodactyl\Exceptions\Service\Allocation\PortOutOfRangeException
+     * @throws \Pterodactyl\Exceptions\Service\Allocation\TooManyPortsInRangeException
+     */
+    public function handle(Server $server)
+    {
+        if (!config('pterodactyl.client_features.allocations.enabled')) {
+            throw new AutoAllocationNotEnabledException;
+        }
+
+        if ($server->allocations()->count() >= $server->allocation_limit) {
+            throw new DisplayException(
+                'Cannot assign additional allocations to this server: limit has been reached.'
+            );
+        }
+
+        // Attempt to find a given available allocation for a server. If one cannot be found
+        // we will fall back to attempting to create a new allocation that can be used for the
+        // server.
+        /** @var \Pterodactyl\Models\Allocation|null $allocation */
+        $allocation = $server->node->allocations()
+            ->where('ip', $server->allocation->ip)
+            ->whereNull('server_id')
+            ->inRandomOrder()
+            ->first();
+
+        $allocation = $allocation ?? $this->createNewAllocation($server);
+
+        $allocation->update(['server_id' => $server->id]);
+
+        return $allocation->refresh();
+    }
+
+    /**
+     * @param \Pterodactyl\Models\Server $server
+     * @return \Pterodactyl\Models\Allocation
+     *
+     * @throws \Pterodactyl\Exceptions\DisplayException
+     * @throws \Pterodactyl\Exceptions\Service\Allocation\CidrOutOfRangeException
+     * @throws \Pterodactyl\Exceptions\Service\Allocation\InvalidPortMappingException
+     * @throws \Pterodactyl\Exceptions\Service\Allocation\PortOutOfRangeException
+     * @throws \Pterodactyl\Exceptions\Service\Allocation\TooManyPortsInRangeException
+     */
+    protected function createNewAllocation(Server $server): Allocation
+    {
+        $start = config('pterodactyl.client_features.allocations.range_start', null);
+        $end = config('pterodactyl.client_features.allocations.range_end', null);
+
+        if (!$start || !$end) {
+            throw new NoAutoAllocationSpaceAvailableException;
+        }
+
+        Assert::integerish($start);
+        Assert::integerish($end);
+
+        // Get all of the currently allocated ports for the node so that we can figure out
+        // which port might be available.
+        $ports = $server->node->allocations()
+            ->where('ip', $server->allocation->ip)
+            ->whereBetween('port', [$start, $end])
+            ->pluck('port');
+
+        // Compute the difference of the range and the currently created ports, finding
+        // any port that does not already exist in the database. We will then use this
+        // array of ports to create a new allocation to assign to the server.
+        $available = array_diff(range($start, $end), $ports->toArray());
+
+        // If we've already allocated all of the ports, just abort.
+        if (empty($available)) {
+            throw new NoAutoAllocationSpaceAvailableException;
+        }
+
+        // dd($available, array_rand($available));
+        // Pick a random port out of the remaining available ports.
+        /** @var int $port */
+        $port = $available[array_rand($available)];
+
+        $this->service->handle($server->node, [
+            'server_id' => $server->id,
+            'allocation_ip' => $server->allocation->ip,
+            'allocation_ports' => [$port],
+        ]);
+
+        /** @var \Pterodactyl\Models\Allocation $allocation */
+        $allocation = $server->node->allocations()
+            ->where('ip', $server->allocation->ip)
+            ->where('port', $port)
+            ->firstOrFail();
+
+        return $allocation;
+    }
+}