issue 974: the serving controller follows its own plan-moved, so a plan moved from the terminal is looked at

cmd/mesh-controller/plan_looks.go

@@ -171,6 +171,9 @@ func startRolloutEvents(ctx context.Context, open *stores, js *broker.JetStream)
 	if err := startProvAppliedLooks(ctx, js); err != nil {
 		fmt.Printf("plans: the provisioner clients' words could not be watched (%v); a walk waits for them until the next look\n", err)
 	}
+	if err := startPlanMovedLooks(ctx, js); err != nil {
+		fmt.Printf("plans: the plans moved by other processes could not be followed (%v)\n", err)
+	}
 	startPlanLooks(ctx, open)
 }
 
@@ -507,6 +510,36 @@ func startProvAppliedLooks(ctx context.Context, js *broker.JetStream) error {
 	return nil
 }
 
+// startPlanMovedLooks has the plans looked at when any process says one moved: the serving controller follows its own
+// `plan-moved`, so a plan a person moved with a verb at the control node's terminal — a process this one did not spawn,
+// whose saves it does not hear — is looked at all the same (novox/hq ADR 0406 §2, §5, issue 974). New messages only; the
+// first look reads the rest. A look its own save asks is the same look: asks are one.
+func startPlanMovedLooks(ctx context.Context, js *broker.JetStream) error {
+	api, err := jetstream.New(js.Conn())
+	if err != nil {
+		return err
+	}
+	stream, err := api.Stream(ctx, broker.EventsStream)
+	if err != nil {
+		return fmt.Errorf("the events stream: %w", err)
+	}
+	consumer, err := stream.OrderedConsumer(ctx, jetstream.OrderedConsumerConfig{
+		FilterSubjects: []string{link.SeatEventSubject(link.MeshControllerSeat, link.KeyPlanMoved)},
+		DeliverPolicy:  jetstream.DeliverNewPolicy})
+	if err != nil {
+		return fmt.Errorf("following the plans moved: %w", err)
+	}
+	consuming, err := consumer.Consume(func(jetstream.Msg) { askToLook() })
+	if err != nil {
+		return fmt.Errorf("following the plans moved: %w", err)
+	}
+	go func() {
+		<-ctx.Done()
+		consuming.Stop()
+	}()
+	return nil
+}
+
 // --- the end of a walk whose end is not known ---
 
 var walkEnds = struct {

cmd/mesh-controller/plan_looks_test.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/novox/mesh-controller/internal/broker"
 	"github.com/novox/mesh-controller/internal/inventory"
+	"github.com/novox/mesh-controller/internal/link"
 	"github.com/novox/mesh-controller/internal/testbus"
 )
 
@@ -315,3 +316,36 @@ func TestKeysThatCannotBeReadAreWatchedByTimersAndTheLookFails(t *testing.T) {
 		t.Error("no timer of its own watches the wait")
 	}
 }
+
+// A plan moved by a process the serving controller did not spawn — a verb run at the control node's terminal — is
+// looked at: the controller follows its own plan-moved (issue 974, round 1).
+func TestAPlanMovedByAnotherProcessAsksForALook(t *testing.T) {
+	js, err := broker.Dial(testbus.URL(t))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(js.Close)
+	if err := broker.AssertMeshStreams(js); err != nil {
+		t.Fatal(err)
+	}
+	var failures, looks atomic.Int32
+	l := lookerCounting(&failures, &looks, nil)
+	lookerMu.Lock()
+	theLooker = l
+	lookerMu.Unlock()
+	t.Cleanup(func() { lookerMu.Lock(); theLooker = nil; lookerMu.Unlock() })
+	ctx, stop := context.WithCancel(context.Background())
+	defer stop()
+	go l.run(ctx)
+	if err := startPlanMovedLooks(ctx, js); err != nil {
+		t.Fatal(err)
+	}
+	legacy, err := js.Conn().JetStream()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := legacy.Publish(link.SeatEventSubject(link.MeshControllerSeat, link.KeyPlanMoved), []byte(`{}`)); err != nil {
+		t.Fatal(err)
+	}
+	eventually(t, "a look on the plan moved", func() bool { return looks.Load() >= 1 })
+}