Manager: mark worker as 'seen' when calling the WorkerState operation

Fix workers timing out when they're `asleep`. When sleeping, the Worker
will call the `WorkerState` operation to see if they have to wake up, but
that didn't mark the workers as "seen". As a result, a sleeping worker
would always time out.

internal/manager/api_impl/workers.go

@@ -180,8 +180,13 @@ func (f *Flamenco) SignOff(e echo.Context) error {
 
 // (GET /api/worker/state)
 func (f *Flamenco) WorkerState(e echo.Context) error {
+	logger := requestLogger(e)
 	worker := requestWorkerOrPanic(e)
 
+	if err := f.workerSeen(logger, worker); err != nil {
+		return sendAPIError(e, http.StatusInternalServerError, "error marking worker as 'seen'")
+	}
+
 	if worker.StatusRequested == "" {
 		return e.NoContent(http.StatusNoContent)
 	}

internal/manager/api_impl/workers_test.go

@@ -271,6 +271,42 @@ func TestWorkerSignoffStatusChangeRequest(t *testing.T) {
 	assertResponseNoContent(t, echo)
 }
 
+func TestWorkerState(t *testing.T) {
+	mockCtrl := gomock.NewController(t)
+	defer mockCtrl.Finish()
+
+	mf := newMockedFlamenco(mockCtrl)
+	worker := testWorker()
+
+	mf.persistence.EXPECT().WorkerSeen(gomock.Any(), &worker).Times(2)
+
+	// No state change requested.
+	{
+		echo := mf.prepareMockedRequest(nil)
+		requestWorkerStore(echo, &worker)
+		err := mf.flamenco.WorkerState(echo)
+		if assert.NoError(t, err) {
+			assertResponseNoContent(t, echo)
+		}
+	}
+
+	// State change requested.
+	{
+		requestStatus := api.WorkerStatusAsleep
+		worker.StatusChangeRequest(requestStatus, false)
+
+		echo := mf.prepareMockedRequest(nil)
+		requestWorkerStore(echo, &worker)
+
+		err := mf.flamenco.WorkerState(echo)
+		if assert.NoError(t, err) {
+			assertResponseJSON(t, echo, http.StatusOK, api.WorkerStateChange{
+				StatusRequested: requestStatus,
+			})
+		}
+	}
+}
+
 func TestWorkerStateChanged(t *testing.T) {
 	mockCtrl := gomock.NewController(t)
 	defer mockCtrl.Finish()