feat(mesh): ConfigSource/ConfigServe options + validator (Phase 3 dark switch)

ConfigSource:Mode = Direct (default, read central SQL) | FetchAndCache (fetch the artifact from central over gRPC, read LocalDb). The validator fails host start on a FetchAndCache shape that cannot fetch — no endpoints, a non-http(s) endpoint, no shared key, or a non-positive timeout — because each otherwise surfaces as a silent absence (a deploy that never applies). ConfigServe (the central serve surface) takes a plain Configure: a 0 port is a valid "disabled". Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW
2026-07-22 19:03:39 -04:00
parent b3cb0f4a54
commit 9d1e60c00c
4 changed files with 278 additions and 0 deletions
@@ -0,0 +1,120 @@
+using Microsoft.Extensions.Options;
+using Shouldly;
+using Xunit;
+
+namespace ZB.MOM.WW.OtOpcUa.Cluster.Tests;
+
+/// <summary>
+///     A <c>FetchAndCache</c> node with no endpoint or no key does not error — it simply never
+///     applies a deployment, and the deploy times out naming a node that is otherwise healthy. These
+///     tests make that misconfiguration a loud host-start failure instead.
+/// </summary>
+public class ConfigSourceOptionsValidatorTests
+{
+    private static ValidateOptionsResult Validate(ConfigSourceOptions o) =>
+        new ConfigSourceOptionsValidator().Validate(ConfigSourceOptions.SectionName, o);
+
+    private static ConfigSourceOptions ValidFetch() => new()
+    {
+        Mode = ConfigSourceOptions.ModeFetchAndCache,
+        CentralFetchEndpoints = ["http://central-1:4055", "http://central-2:4055"],
+        ApiKey = "shared-key",
+        FetchTimeoutSeconds = 30,
+    };
+
+    [Fact]
+    public void Default_options_are_valid()
+    {
+        // The default is Direct with everything empty — the pre-Phase-3 behaviour. A node that never
+        // sets this section must validate, which is the premise of the dark switch.
+        Validate(new ConfigSourceOptions()).Succeeded.ShouldBeTrue();
+    }
+
+    [Fact]
+    public void Unknown_mode_fails()
+    {
+        var result = Validate(new ConfigSourceOptions { Mode = "cache" });
+
+        result.Failed.ShouldBeTrue();
+        result.FailureMessage.ShouldContain("cache");
+    }
+
+    [Fact]
+    public void Mode_matching_is_case_insensitive()
+    {
+        Validate(new ConfigSourceOptions
+        {
+            Mode = "fetchandcache",
+            CentralFetchEndpoints = ["http://central-1:4055"],
+            ApiKey = "k",
+        }).Succeeded.ShouldBeTrue();
+    }
+
+    [Fact]
+    public void FetchAndCache_with_no_endpoints_fails()
+    {
+        var o = ValidFetch();
+        o.CentralFetchEndpoints = [];
+
+        var result = Validate(o);
+
+        result.Failed.ShouldBeTrue();
+        result.FailureMessage.ShouldContain(nameof(ConfigSourceOptions.CentralFetchEndpoints));
+    }
+
+    [Fact]
+    public void FetchAndCache_with_a_non_http_endpoint_fails()
+    {
+        var o = ValidFetch();
+        o.CentralFetchEndpoints = ["central-1:4055"];
+
+        var result = Validate(o);
+
+        result.Failed.ShouldBeTrue();
+        result.FailureMessage.ShouldContain("central-1:4055");
+    }
+
+    [Fact]
+    public void FetchAndCache_with_an_empty_key_fails()
+    {
+        var o = ValidFetch();
+        o.ApiKey = "";
+
+        var result = Validate(o);
+
+        result.Failed.ShouldBeTrue();
+        result.FailureMessage.ShouldContain(nameof(ConfigSourceOptions.ApiKey));
+    }
+
+    [Fact]
+    public void FetchAndCache_with_a_non_positive_timeout_fails()
+    {
+        var o = ValidFetch();
+        o.FetchTimeoutSeconds = 0;
+
+        var result = Validate(o);
+
+        result.Failed.ShouldBeTrue();
+        result.FailureMessage.ShouldContain(nameof(ConfigSourceOptions.FetchTimeoutSeconds));
+    }
+
+    [Fact]
+    public void A_fully_populated_FetchAndCache_config_is_valid()
+    {
+        Validate(ValidFetch()).Succeeded.ShouldBeTrue();
+    }
+
+    [Fact]
+    public void Direct_ignores_the_empty_fetch_surface()
+    {
+        // Under Direct the endpoints/key are never read, so their emptiness must not fail validation —
+        // otherwise every admin-only and every Direct node would be forced to carry fetch config.
+        Validate(new ConfigSourceOptions
+        {
+            Mode = ConfigSourceOptions.ModeDirect,
+            CentralFetchEndpoints = [],
+            ApiKey = "",
+            FetchTimeoutSeconds = 0,
+        }).Succeeded.ShouldBeTrue();
+    }
+}