✨ Gateway readiness check

DysonNetwork.Gateway/Health/GatewayHealthAggregator.cs

@@ -0,0 +1,60 @@
+using NodaTime;
+
+namespace DysonNetwork.Gateway.Health;
+
+public class GatewayHealthAggregator(IHttpClientFactory httpClientFactory, GatewayReadinessStore store)
+    : BackgroundService
+{
+    private async Task<ServiceHealthState> CheckService(string serviceName)
+    {
+        var client = httpClientFactory.CreateClient("health");
+        var now = SystemClock.Instance.GetCurrentInstant();
+
+        try
+        {
+            // Use the service discovery to lookup service
+            // The service defaults give every single service a health endpoint that we can use here
+            using var response = await client.GetAsync($"http://{serviceName}/health");
+
+            if (response.IsSuccessStatusCode)
+            {
+                return new ServiceHealthState(
+                    serviceName,
+                    true,
+                    now,
+                    null
+                );
+            }
+
+            return new ServiceHealthState(
+                serviceName,
+                false,
+                now,
+                $"StatusCode: {(int)response.StatusCode}"
+            );
+        }
+        catch (Exception ex)
+        {
+            return new ServiceHealthState(
+                serviceName,
+                false,
+                now,
+                ex.Message
+            );
+        }
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            foreach (var service in GatewayConstant.ServiceNames)
+            {
+                var result = await CheckService(service);
+                store.Update(result);
+            }
+
+            await Task.Delay(TimeSpan.FromSeconds(5), stoppingToken);
+        }
+    }
+}