refactor(host): CentralSingletonRegistrar -> SingletonRegistrar with optional role scope — unblocks site-singleton drains (plan R2-01 T10)

2026-07-13 10:49:49 -04:00
parent c2707fdcf8
commit 80e5b36852
4 changed files with 55 additions and 25 deletions
@@ -0,0 +1,79 @@
+using Akka.Actor;
+using Akka.Configuration;
+using Microsoft.Extensions.Logging.Abstractions;
+using ZB.MOM.WW.ScadaBridge.Host.Actors;
+
+namespace ZB.MOM.WW.ScadaBridge.Host.Tests;
+
+public class SingletonRegistrarTests
+{
+    private sealed class EchoActor : ReceiveActor
+    {
+        public EchoActor() => ReceiveAny(m => Sender.Tell(m));
+    }
+
+    [Fact]
+    public async Task Start_CreatesManagerAndProxy_WithCanonicalNames_AndDrainTask()
+    {
+        using var system = CreateSingleNodeClusterSystem();
+        var handle = SingletonRegistrar.Start(
+            system, "test-widget", Props.Create(() => new EchoActor()),
+            NullLogger.Instance, drainTimeout: TimeSpan.FromSeconds(2));
+
+        // Canonical naming preserved: <name>-singleton / <name>-proxy.
+        Assert.EndsWith("/user/test-widget-singleton", handle.Manager.Path.ToString());
+        Assert.EndsWith("/user/test-widget-proxy", handle.Proxy.Path.ToString());
+
+        // Singleton answers through the proxy once the member is Up.
+        var echo = await handle.Proxy.Ask<string>("hi", TimeSpan.FromSeconds(20));
+        Assert.Equal("hi", echo);
+
+        // The drain task registered on PhaseClusterLeave must stop the manager
+        // during coordinated shutdown.
+        await Akka.Actor.CoordinatedShutdown.Get(system).Run(
+            Akka.Actor.CoordinatedShutdown.ClrExitReason.Instance);
+        // Manager terminated => drain ran (GracefulStop completed or PoisonPill fallback).
+        Assert.True(handle.Manager.IsNobody() || system.WhenTerminated.IsCompleted);
+    }
+
+    [Fact]
+    public async Task Start_WithRoleScope_CreatesRoleScopedSingleton_ThatAnswers()
+    {
+        // Round-2 N5: role scoping is what kept the two SITE singletons
+        // (deployment-manager, event-log-handler) hand-rolled and drain-less.
+        using var system = CreateSingleNodeClusterSystem(); // roles = ["Central"]
+        var handle = SingletonRegistrar.Start(
+            system, "role-widget", Props.Create(() => new EchoActor()),
+            NullLogger.Instance, drainTimeout: TimeSpan.FromSeconds(2), role: "Central");
+
+        Assert.EndsWith("/user/role-widget-singleton", handle.Manager.Path.ToString());
+        Assert.EndsWith("/user/role-widget-proxy", handle.Proxy.Path.ToString());
+
+        // The node holds the role => manager instantiates the singleton and
+        // the role-scoped proxy resolves it.
+        var echo = await handle.Proxy.Ask<string>("hi", TimeSpan.FromSeconds(20));
+        Assert.Equal("hi", echo);
+    }
+
+    private static ActorSystem CreateSingleNodeClusterSystem()
+    {
+        var port = FreePort();
+        var config = ConfigurationFactory.ParseString($@"
+akka {{
+    actor.provider = cluster
+    remote.dot-netty.tcp {{ hostname = ""127.0.0.1"", port = {port} }}
+    cluster {{
+        seed-nodes = [""akka.tcp://registrar-test@127.0.0.1:{port}""]
+        roles = [""Central""]
+        min-nr-of-members = 1
+    }}
+}}");
+        return ActorSystem.Create("registrar-test", config);
+    }
+
+    private static int FreePort()
+    {
+        var l = new System.Net.Sockets.TcpListener(System.Net.IPAddress.Loopback, 0);
+        l.Start(); var p = ((System.Net.IPEndPoint)l.LocalEndpoint).Port; l.Stop(); return p;
+    }
+}