Say whether a plan hands its module in one rule, Plan.Hands, so no reader takes a plan naming provisions alone for a handed module (issue 774)

go/catalogue/handed.go

@@ -66,6 +66,16 @@ type Plan struct {
 	Provisions []PlanProvision `json:"provisions,omitempty"`
 }
 
+// Hands is whether the plan hands its module to the provisioner: it names something the node's provisioner client fills
+// (a template archive, a file, an own secret or an item), and the node composes none of it. A plan naming provisions alone
+// hands nothing (catalogue.Keyed, issue 774): the seat keys what a provider's helper answers of a module not handed, and
+// that module's files and own secrets stay its node's composition. The one rule every reader of a plan asks; whether a
+// plan exists is never it (on 2026-10-30 the vault read every route-only plan as handed and answered twenty modules'
+// own secrets to nobody).
+func (p Plan) Hands() bool {
+	return p.Templates.Source != "" || len(p.Files) > 0 || len(p.Secrets) > 0 || len(p.Items) > 0
+}
+
 // PlanItem is one item the module contributes: to which collection, and its template inside the archive.
 //
 // A named item has its Name and Attributes (design 57 L3, issue 777): the client records them with the item and

go/catalogue/keyed_test.go

@@ -104,6 +104,28 @@ func TestAModuleNotHandedHasAPlanForWhatAHelperAnswers(t *testing.T) {
 		!strings.Contains(plan.Provisions[0].As, "notify") || plan.Provisions[0].Contributes["host"] != "notify.example.org" {
 		t.Fatalf("the plan names %+v", plan)
 	}
+	// And it hands nothing: Plan.Hands, the one rule every reader of a plan asks, by each part a plan can name.
+	if plan.Hands() {
+		t.Fatalf("a plan naming the route alone hands its module: %+v", plan)
+	}
+	for _, c := range []struct {
+		name  string
+		plan  Plan
+		hands bool
+	}{
+		{"empty", Plan{}, false},
+		{"provisions alone", Plan{Provisions: plan.Provisions}, false},
+		{"a digest without an archive", Plan{Templates: PlanTemplates{Digest: "sha256:1"}}, false},
+		{"templates alone", Plan{Templates: PlanTemplates{Source: "notify.tar", Digest: "sha256:1"}}, true},
+		{"files alone", Plan{Files: []PlanFile{{ID: "conf", Path: "/etc/notify.conf"}}}, true},
+		{"secrets alone", Plan{Secrets: []PlanSecret{{Name: "admin"}}}, true},
+		{"items alone", Plan{Items: []PlanItem{{Collection: "routes", Template: "route.tmpl"}}}, true},
+		{"secrets and provisions", Plan{Secrets: []PlanSecret{{Name: "admin"}}, Provisions: plan.Provisions}, true},
+	} {
+		if got := c.plan.Hands(); got != c.hands {
+			t.Errorf("%s: Hands() is %v, want %v", c.name, got, c.hands)
+		}
+	}
 	if want := Awaited(consumer, func(p string) []Manifest {
 		return map[string][]Manifest{"route": {proxy}, "postgres-database": {store}}[p]
 	}); !reflect.DeepEqual(want, []string{"route"}) {