Support for waiting on tcp port to open

src/Container/Container.php

@@ -56,6 +56,11 @@ class Container
         return new Container($image);
     }
 
+    public function getId(): string
+    {
+        return $this->id;
+    }
+
     public function withEntryPoint(string $entryPoint): self
     {
         $this->entryPoint = $entryPoint;

src/Wait/WaitForTcpPortOpen.php

@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Testcontainer\Wait;
+
+use JsonException;
+use RuntimeException;
+use Symfony\Component\Process\Process;
+use Testcontainer\Exception\ContainerNotReadyException;
+
+/**
+ * @phpstan-type ContainerInspect array<int, array{'NetworkSettings': array{'IPAddress': string}}>
+ */
+final class WaitForTcpPortOpen implements WaitInterface
+{
+    public function __construct(private readonly int $port)
+    {
+    }
+
+    public static function make(int $port): self
+    {
+        return new self($port);
+    }
+
+    /**
+     * @throws JsonException
+     */
+    public function wait(string $id): void
+    {
+        if (@fsockopen($this->findContainerAddress($id), $this->port) === false) {
+            throw new ContainerNotReadyException($id, new RuntimeException('Unable to connect to container TCP port'));
+        }
+    }
+
+    /**
+     * @throws JsonException
+     */
+    private function findContainerAddress(string $id): string
+    {
+        $process = new Process(['docker', 'inspect', $id]);
+        $process->mustRun();
+
+        /** @var ContainerInspect $data */
+        $data = json_decode($process->getOutput(), true, 512, JSON_THROW_ON_ERROR);
+
+        $containerAddress = $data[0]['NetworkSettings']['IPAddress'] ?? null;
+
+        if (! is_string($containerAddress)) {
+            throw new ContainerNotReadyException($id, new RuntimeException('Unable to find container IP address'));
+        }
+
+        return $containerAddress;
+    }
+}

tests/Integration/WaitStrategyTest.php

@@ -9,10 +9,12 @@ use Predis\Client;
 use Predis\Connection\ConnectionException;
 use Symfony\Component\Process\Process;
 use Testcontainer\Container\Container;
+use Testcontainer\Exception\ContainerNotReadyException;
 use Testcontainer\Wait\WaitForExec;
 use Testcontainer\Wait\WaitForHealthCheck;
 use Testcontainer\Wait\WaitForHttp;
 use Testcontainer\Wait\WaitForLog;
+use Testcontainer\Wait\WaitForTcpPortOpen;
 
 class WaitStrategyTest extends TestCase
 {
@@ -90,6 +92,42 @@ class WaitStrategyTest extends TestCase
         $this->assertNotEmpty($response);
     }
 
+    /**
+     * @dataProvider provideWaitForTcpPortOpen
+     */
+    public function testWaitForTcpPortOpen(bool $canConnect): void
+    {
+        $container = Container::make('nginx:alpine');
+
+        if ($canConnect) {
+            $container->withWait(WaitForTcpPortOpen::make(80));
+        }
+
+        $container->run();
+
+        if ($canConnect) {
+            static::assertIsResource(fsockopen($container->getAddress(), 80), 'Failed to connect to container');
+            return;
+        }
+
+        $containerId = $container->getId();
+
+        $this->expectExceptionObject(new ContainerNotReadyException($containerId));
+
+        (new WaitForTcpPortOpen(8080))->wait($containerId);
+    }
+
+    /**
+     * @return array<string, array<bool>>
+     */
+    public function provideWaitForTcpPortOpen(): array
+    {
+        return [
+            'Can connect to container' => [true],
+            'Cannot connect to container' => [false],
+        ];
+    }
+
     public function testWaitForHealthCheck(): void
     {
         $container = Container::make('nginx')