feat(health.akka): active/leader check with role filter + IActiveNodeGate impl

2026-06-01 06:55:46 -04:00
parent 2dbedce0ac
commit cf277eb7df
3 changed files with 279 additions and 0 deletions
@@ -0,0 +1,50 @@
+using Akka.Actor;
+using Akka.Cluster;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace ZB.MOM.WW.Health.Akka;
+
+/// <summary>
+/// <see cref="IActiveNodeGate"/> implementation that computes <see cref="IsActiveNode"/> directly
+/// from the Akka cluster state (self member <c>Up</c> and the local node is the cluster leader).
+/// Register as a singleton.
+/// </summary>
+/// <remarks>
+/// The <see cref="ActorSystem"/> is resolved lazily from the service provider; if it is not yet
+/// available — e.g. during startup before Akka is initialised — <see cref="IsActiveNode"/> returns
+/// <c>false</c> (the safe default during startup). This gate reads the cluster state directly and
+/// does not resolve <see cref="ActiveNodeHealthCheck"/> from DI.
+/// </remarks>
+public sealed class AkkaActiveNodeGate : IActiveNodeGate
+{
+    private readonly IServiceProvider _serviceProvider;
+
+    /// <summary>Initializes a new <see cref="AkkaActiveNodeGate"/>.</summary>
+    /// <param name="serviceProvider">
+    /// The application service provider. The <see cref="ActorSystem"/> is resolved lazily; if it is
+    /// not yet available <see cref="IsActiveNode"/> returns <c>false</c>.
+    /// </param>
+    public AkkaActiveNodeGate(IServiceProvider serviceProvider)
+    {
+        _serviceProvider = serviceProvider ?? throw new ArgumentNullException(nameof(serviceProvider));
+    }
+
+    /// <inheritdoc />
+    public bool IsActiveNode
+    {
+        get
+        {
+            var system = _serviceProvider.GetService<ActorSystem>();
+            if (system is null)
+                return false;
+
+            var cluster = Cluster.Get(system);
+            var self = cluster.SelfMember;
+            if (self.Status != MemberStatus.Up)
+                return false;
+
+            var leader = cluster.State.Leader;
+            return leader is not null && leader == self.Address;
+        }
+    }
+}