feat: add preprod observability foundation

backend/src/Socialize.Api/Infrastructure/Observability/LocalBlobStorageHealthCheck.cs

@@ -0,0 +1,40 @@
+using Microsoft.Extensions.Diagnostics.HealthChecks;
+using Microsoft.Extensions.Options;
+using Socialize.Api.Infrastructure.BlobStorage.Configuration;
+using Socialize.Api.Infrastructure.BlobStorage.Services;
+
+namespace Socialize.Api.Infrastructure.Observability;
+
+internal sealed class LocalBlobStorageHealthCheck(
+    LocalBlobStorage blobStorage,
+    IOptions<LocalBlobStorageOptions> options)
+    : IHealthCheck
+{
+    public async Task<HealthCheckResult> CheckHealthAsync(
+        HealthCheckContext context,
+        CancellationToken cancellationToken = default)
+    {
+        string rootPath = blobStorage.GetRootPath();
+        if (string.IsNullOrWhiteSpace(options.Value.RequestPath))
+        {
+            return HealthCheckResult.Unhealthy("Local blob storage request path is not configured.");
+        }
+
+        try
+        {
+            Directory.CreateDirectory(rootPath);
+            string probePath = Path.Combine(rootPath, ".healthcheck");
+            await File.WriteAllTextAsync(
+                probePath,
+                DateTimeOffset.UtcNow.ToString("O", System.Globalization.CultureInfo.InvariantCulture),
+                cancellationToken);
+            File.Delete(probePath);
+
+            return HealthCheckResult.Healthy("Local blob storage is writable.");
+        }
+        catch (Exception ex) when (ex is IOException or UnauthorizedAccessException)
+        {
+            return HealthCheckResult.Unhealthy("Local blob storage is not writable.", ex);
+        }
+    }
+}