Add a health check example

src/HealthCheck/HealthCheck.php

+<?php
+
+declare(strict_types=1);
+
+namespace Dbp\Relay\ExampleBundle\HealthCheck;
+
+use Dbp\Relay\CoreBundle\HealthCheck\CheckInterface;
+use Dbp\Relay\CoreBundle\HealthCheck\CheckOptions;
+use Dbp\Relay\CoreBundle\HealthCheck\CheckResult;
+
+class HealthCheck implements CheckInterface
+{
+    public function getName(): string
+    {
+        return 'example';
+    }
+
+    public function check(CheckOptions $options): array
+    {
+        $ok = new CheckResult('Check that everything is OK');
+        $ok->set(CheckResult::STATUS_SUCCESS, 'everything OK');
+
+        $failed = new CheckResult('Check something different');
+        try {
+            throw new \RuntimeException('oh no');
+        } catch (\Throwable $e) {
+            $failed->set(CheckResult::STATUS_FAILURE, $e->getMessage(), ['exception' => $e]);
+        }
+
+        return [$ok, $failed];
+    }
+}

src/Resources/config/services.yaml

@@ -22,6 +22,10 @@ services:
     autowire: true
     autoconfigure: true
 
+  Dbp\Relay\ExampleBundle\HealthCheck\HealthCheck:
+    autowire: true
+    autoconfigure: true
+
   Dbp\Relay\ExampleBundle\Service\MyCustomService:
     autowire: true
     autoconfigure: true