Manager: use blocklist to actually block workers

Actually use the blocklist in the task scheduler to block workers from
doing blocked job types.

internal/manager/persistence/task_scheduler.go

@@ -111,6 +111,11 @@ func findTaskForWorker(tx *gorm.DB, w *Worker) (*Task, error) {
 		Where("tasks2.id = tasks.id").
 		Where("dep.status is not NULL and dep.status != ?", api.TaskStatusCompleted)
 
+	blockedTaskTypesQuery := tx.Model(&JobBlock{}).
+		Select("job_blocks.task_type").
+		Where("job_blocks.worker_id = ?", w.ID).
+		Where("job_blocks.job_id = jobs.id")
+
 	// Note that this query doesn't check for the assigned worker. Tasks that have
 	// a 'schedulable' status might have been assigned to a worker, representing
 	// the last worker to touch it -- it's not meant to indicate "ownership" of
@@ -124,7 +129,7 @@ func findTaskForWorker(tx *gorm.DB, w *Worker) (*Task, error) {
 		Where("tasks.type in ?", w.TaskTypes()).               // Supported task types
 		Where("tasks.id not in (?)", incompleteDepsQuery).     // Dependencies completed
 		Where("TF.worker_id is NULL").                         // Not failed before
-		// TODO: Non-blocklisted
+		Where("tasks.type not in (?)", blockedTaskTypesQuery). // Non-blocklisted
 		Order("jobs.priority desc").                           // Highest job priority
 		Order("tasks.priority desc").                          // Highest task priority
 		Limit(1).

internal/manager/persistence/task_scheduler_test.go

@@ -289,6 +289,33 @@ func TestPreviouslyFailed(t *testing.T) {
 	assert.Equal(t, att2.Name, task.Name, "the second task should have been chosen")
 }
 
+func TestBlocklisted(t *testing.T) {
+	ctx, cancel, db := persistenceTestFixtures(t, schedulerTestTimeout)
+	defer cancel()
+
+	w := linuxWorker(t, db)
+
+	att1 := authorTestTask("1 blocked task", "blender")
+	att2 := authorTestTask("2 expected task", "ffmpeg")
+	atj := authorTestJob(
+		"1295757b-e668-4c49-8b89-f73db8270e42",
+		"simple-blender-render",
+		att1, att2)
+	job := constructTestJob(ctx, t, db, atj)
+
+	// Mimick that this worker was already blocked for 'blender' tasks of this job.
+	err := db.AddWorkerToJobBlocklist(ctx, job, &w, "blender")
+	assert.NoError(t, err)
+
+	// This should assign the 2nd task.
+	task, err := db.ScheduleTask(ctx, &w)
+	assert.NoError(t, err)
+	if task == nil {
+		t.Fatal("task is nil")
+	}
+	assert.Equal(t, att2.Name, task.Name, "the second task should have been chosen")
+}
+
 // To test: blocklists
 
 // To test: variable replacement