Derive the guard from taken modules only: their published private-network ports and their manifests' guards (hq ADR 0103)

internal/catalogue/adoption_test.go

@@ -59,6 +59,8 @@ func anchorRendering(adopted bool) Rendering {
 		Mesh:       []string{"10.42.0.1"},
 		Foundation: []int{5671},
 		Adopted:    adopted,
+		// Genesis takes the foundation's modules.
+		Taken: map[string]bool{"postgres": true, "lavinmq": true},
 	}
 }
 
@@ -151,8 +153,9 @@ func TestAnAdoptedNodeLoadsNoFilterOfTheMeshs(t *testing.T) {
 	if guard == nil || got[GuardUnitID()] == nil || got[GuardRunningID()] == nil {
 		t.Fatalf("no guard: %v", keys(got))
 	}
-	if guard["content"] != AsGuard([]int{5432, 15672}) {
-		t.Fatalf("the guard does not guard the store and the management port:\n%s", guard["content"])
+	if guard["content"] != AsGuard([]int{5432, 5672, 15672}) {
+		t.Fatalf("the guard does not guard the store, the broker and its management port:\n%s",
+			guard["content"])
 	}
 	if !reflect.DeepEqual(got[GuardRunningID()]["restart-on"], []any{GuardID(), GuardUnitID()}) {
 		t.Fatalf("the guard is not reloaded when its table changes: %v", got[GuardRunningID()])
@@ -252,7 +255,7 @@ func TestAGivenPortIsUsedEverywhereThePortIs(t *testing.T) {
 		if o := got["adoption.opening-tcp-5433-forwarded"]; o == nil || o["to"] != 5432 {
 			t.Fatalf("no opening for the given port: %v", keys(got))
 		}
-		if guard := got[GuardID()]["content"]; guard != AsGuard([]int{5433, 15673}) {
+		if guard := got[GuardID()]["content"]; guard != AsGuard([]int{5433, 5672, 15673}) {
 			t.Fatalf("the guard does not guard the given ports:\n%s", guard)
 		}
 	}
@@ -281,3 +284,55 @@ func TestAGivenPortIsTheNodesAndReachesSomething(t *testing.T) {
 		t.Fatalf("a given port is called stray: %v", stray)
 	}
 }
+
+// novox/hq ADR 0103: the guard is derived, and from taken modules only — every machine port a taken
+// module publishes that the filter admits from the private network only, and the ports its
+// manifest guards. A module assigned but not taken is not guarded: its port may still be the
+// predecessor's.
+func TestTheGuardIsDerivedFromTakenModulesOnly(t *testing.T) {
+	guardOf := func(with Rendering) string {
+		t.Helper()
+		composed, err := anAdoptedAnchor().Compose(with)
+		if err != nil {
+			t.Fatal(err)
+		}
+		content, _ := byID(composed.Resources)[GuardID()]["content"].(string)
+		return content
+	}
+
+	// The broker taken, the store not: the broker's plain port follows from its listens (from
+	// the mesh, published), its management port from its manifest; the store is not guarded, and
+	// neither is the bus, which the mesh needs from everywhere.
+	with := anchorRendering(true)
+	with.Taken = map[string]bool{"lavinmq": true}
+	if got := guardOf(with); got != AsGuard([]int{5672, 15672}) {
+		t.Fatalf("the guard is not the taken broker's ports:\n%s", got)
+	}
+
+	// A taken module publishing a port admitted from everywhere is not guarded; one admitted from
+	// the mesh is. The registry is exposed everywhere on this node, and hello-web listens from
+	// everywhere.
+	with.Taken = map[string]bool{"distribution": true, "hello-web": true}
+	if got := guardOf(with); got != "" {
+		t.Fatalf("a port admitted from everywhere is guarded:\n%s", got)
+	}
+	with.Settings = nil
+	if got := guardOf(with); got != AsGuard([]int{5000}) {
+		t.Fatalf("the registry, from the mesh only, is not guarded:\n%s", got)
+	}
+
+	// Nothing taken, nothing guarded — and no guard at all rather than an empty set.
+	with = anchorRendering(true)
+	with.Taken = nil
+	if got := guardOf(with); got != "" {
+		t.Fatalf("an untaken store is guarded:\n%s", got)
+	}
+
+	// A given port is followed: where the machine put it is what is refused.
+	with = anchorRendering(true)
+	with.Given = map[string]map[int]int{"lavinmq": {5672: 5682, 15672: 15673}}
+	with.Ports["lavinmq"] = map[int]int{5671: 5671, 5672: 5682}
+	if got := guardOf(with); got != AsGuard([]int{5432, 5682, 15673}) {
+		t.Fatalf("the guard does not follow the given ports:\n%s", got)
+	}
+}