feat(localdb): gRPC sync adapters, background service, replication DI

Claude-Session: https://claude.ai/code/session_01BL2Vu1ESDQ9SCN4gVKkdts
2026-07-17 23:01:29 -04:00
parent 183901e8ac
commit a64fc26391
7 changed files with 701 additions and 0 deletions
@@ -0,0 +1,54 @@
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+using Microsoft.Extensions.Options;
+
+namespace ZB.MOM.WW.LocalDb.Replication;
+
+/// <summary>DI + endpoint wiring for the 2-node gRPC replication engine.</summary>
+public static class ReplicationServiceCollectionExtensions
+{
+    /// <summary>
+    /// Binds and validates <see cref="ReplicationOptions"/> from the <c>"LocalDb:Replication"</c>
+    /// configuration section, registers the passive <see cref="LocalDbSyncService"/> as a singleton
+    /// (its single-stream guard must span calls), and registers the initiating
+    /// <see cref="SyncBackgroundService"/> as a hosted service ONLY when a peer address is configured
+    /// (a passive node leaves it empty and never dials). Idempotent. Requires
+    /// <see cref="LocalDbServiceCollectionExtensions.AddZbLocalDb"/> to have been called for the
+    /// <see cref="ILocalDb"/> the adapters depend on.
+    /// </summary>
+    public static IServiceCollection AddZbLocalDbReplication(
+        this IServiceCollection services, IConfiguration configuration)
+    {
+        // Idempotent: a second call must not re-bind options or double-register the service/host.
+        if (services.Any(d => d.ServiceType == typeof(LocalDbSyncService)))
+            return services;
+
+        services.AddOptions<ReplicationOptions>()
+            .Bind(configuration.GetSection("LocalDb:Replication"))
+            .ValidateOnStart();
+        services.TryAddEnumerable(
+            ServiceDescriptor.Singleton<IValidateOptions<ReplicationOptions>, ReplicationOptionsValidator>());
+
+        services.AddSingleton<LocalDbSyncService>();
+
+        // Read the section directly (before options are built) to decide whether this node initiates.
+        var peerAddress = configuration.GetSection("LocalDb:Replication")["PeerAddress"];
+        if (!string.IsNullOrEmpty(peerAddress))
+            services.AddHostedService<SyncBackgroundService>();
+
+        return services;
+    }
+
+    /// <summary>
+    /// Maps the passive <see cref="LocalDbSyncService"/> gRPC endpoint. The host must have called
+    /// <c>AddGrpc()</c> and set up routing.
+    /// </summary>
+    public static IEndpointRouteBuilder MapZbLocalDbSync(this IEndpointRouteBuilder endpoints)
+    {
+        endpoints.MapGrpcService<LocalDbSyncService>();
+        return endpoints;
+    }
+}