Prove on a real bus the controller asks mesh-config in its own name (issue 925)

internal/broker/config_owner_live_test.go

@@ -160,3 +160,87 @@ func TestNatsOnlyMeshConfigsAccountPutsToItsBuckets(t *testing.T) {
 		}
 	}
 }
+
+// **The controller asks mesh-config's `config` in its own name** (issue 925): on a real server whose users are
+// composed from records that hold mesh-config on novox serving `config`, the controller's request on
+// `mesh.seat.mesh-config.call.config.controller` reaches mesh-config's account and its reply reaches the
+// controller's inbox; the same request under another caller's name is refused by the server.
+func TestNatsTheControllerAsksMeshConfigInItsOwnName(t *testing.T) {
+	hash, err := bcrypt.GenerateFromPassword([]byte("pw"), bcrypt.MinCost)
+	if err != nil {
+		t.Fatal(err)
+	}
+	seat := Seat{Name: "mesh-config", Scope: "mesh", Serves: []string{"config"}}
+	users, err := Users(Records{Nodes: []string{"novox"}, Assigned: map[string][]Declared{
+		"novox": {{Module: RuntimeModule}, {Module: "mesh-config", RunsAs: "mesh-config", Holds: []Seat{seat}}},
+	}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	for i := range users {
+		users[i].PasswordHash = string(hash)
+	}
+	accounts, err := ComposeAccounts(users)
+	if err != nil {
+		t.Fatal(err)
+	}
+	conf := filepath.Join(t.TempDir(), "bus.conf")
+	if err := os.WriteFile(conf, []byte("listen: 127.0.0.1:-1\n"+accounts), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	opts, err := server.ProcessConfigFile(conf)
+	if err != nil {
+		t.Fatalf("the composed accounts do not parse: %v", err)
+	}
+	opts.NoLog, opts.NoSigs = true, true
+	s, err := server.NewServer(opts)
+	if err != nil {
+		t.Fatal(err)
+	}
+	go s.Start()
+	if !s.ReadyForConnections(10 * time.Second) {
+		t.Fatal("the bus did not come up")
+	}
+	t.Cleanup(s.Shutdown)
+	connect := func(user string) (*nats.Conn, chan error) {
+		t.Helper()
+		refused := make(chan error, 8)
+		nc, err := nats.Connect(s.ClientURL(), nats.UserInfo(user, "pw"), nats.CustomInboxPrefix("_INBOX."+user),
+			nats.ErrorHandler(func(_ *nats.Conn, _ *nats.Subscription, err error) { refused <- err }))
+		if err != nil {
+			t.Fatalf("%s cannot connect: %v", user, err)
+		}
+		t.Cleanup(nc.Close)
+		return nc, refused
+	}
+	owner, _ := connect("novox.mesh-config")
+	subject := CalledSubject("mesh.seat.mesh-config.tool.config", ControllerName)
+	if subject != "mesh.seat.mesh-config.call.config.controller" {
+		t.Fatalf("the subject is %s", subject)
+	}
+	if _, err := owner.Subscribe("mesh.seat.mesh-config.call.config.*", func(m *nats.Msg) {
+		_ = m.Respond([]byte(`{"ok":true}`))
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if err := owner.Flush(); err != nil {
+		t.Fatal(err)
+	}
+	controller, refused := connect(ControllerName)
+	reply, err := controller.Request(subject, []byte(`{"action":"set"}`), 5*time.Second)
+	if err != nil || string(reply.Data) != `{"ok":true}` {
+		t.Fatalf("the controller's own-name request got %v (%v), want mesh-config's reply", reply, err)
+	}
+	if err := controller.Publish(CalledSubject("mesh.seat.mesh-config.tool.config", "anchor.node-tools"), nil); err != nil {
+		t.Fatal(err)
+	}
+	_ = controller.Flush()
+	select {
+	case err := <-refused:
+		if !errors.Is(err, nats.ErrPermissionViolation) {
+			t.Errorf("the server said %v, want a permissions violation", err)
+		}
+	case <-time.After(3 * time.Second):
+		t.Error("the server did not refuse the controller a request in another's name")
+	}
+}