always allow running at least 1 job

* Regardless of capacity
* Add unit tests around this logic

awx/main/scheduler/__init__.py

@@ -243,7 +243,6 @@ class TaskManager():
 
             for inventory_source_task in self.graph.get_inventory_sources(task['inventory_id']):
                 if inventory_source_task['id'] in inventory_sources_already_updated:
-                    print("Inventory already updated")
                     continue
                 if self.graph.should_update_related_inventory_source(task, inventory_source_task['id']):
                     inventory_task = self.create_inventory_update(task, inventory_source_task)
@@ -316,6 +315,8 @@ class TaskManager():
             self.capacity_used += t.task_impact()
 
     def would_exceed_capacity(self, task):
+        if self.capacity_used == 0:
+            return False
         return (task.task_impact() + self.capacity_used > self.capacity_total)
 
     def consume_capacity(self, task):

awx/main/tests/unit/scheduler/conftest.py

@@ -22,7 +22,7 @@ def epoch():
 
 @pytest.fixture
 def scheduler_factory(mocker, epoch):
-    mocker.patch('awx.main.models.Instance.objects.total_capacity', return_value=999999999)
+    mocker.patch('awx.main.models.Instance.objects.total_capacity', return_value=10000)
 
     def fn(tasks=[], inventory_sources=[], latest_project_updates=[], latest_inventory_updates=[], create_project_update=None, create_inventory_update=None):
         sched = TaskManager()
@@ -190,15 +190,15 @@ Job
 '''
 @pytest.fixture
 def job_factory(epoch):
-    def fn(project__scm_update_on_launch=True, inventory__inventory_sources=[]):
+    def fn(id=1, project__scm_update_on_launch=True, inventory__inventory_sources=[], allow_simultaneous=False):
         return JobDict({ 
-            'id': 1, 
+            'id': id,
             'status': 'pending', 
             'job_template_id': 1, 
             'project_id': 1, 
             'inventory_id': 1,
             'launch_type': 'manual', 
-            'allow_simultaneous': False, 
+            'allow_simultaneous': allow_simultaneous,
             'created': epoch - timedelta(seconds=99), 
             'celery_task_id': '', 
             'project__scm_update_on_launch': project__scm_update_on_launch, 

awx/main/tests/unit/scheduler/test_scheduler_job.py

@@ -54,3 +54,31 @@ class TestJob():
 
         scheduler.start_task.assert_called_with(pending_job)
 
+class TestCapacity():
+    @pytest.fixture
+    def pending_job_high_impact(self, mocker, job_factory):
+        pending_job = job_factory(project__scm_update_on_launch=False)
+        mocker.patch.object(pending_job, 'task_impact', return_value=10001)
+        return pending_job
+
+    def test_no_capacity(self, scheduler_factory, pending_job_high_impact):
+        scheduler = scheduler_factory(tasks=[pending_job_high_impact])
+
+        scheduler._schedule()
+
+        scheduler.start_task.assert_called_with(pending_job_high_impact)
+
+    @pytest.fixture
+    def pending_jobs_impactful(self, mocker, job_factory):
+        pending_jobs = [job_factory(id=i + 1, project__scm_update_on_launch=False, allow_simultaneous=True) for i in xrange(0, 3)]
+        map(lambda pending_job: mocker.patch.object(pending_job, 'task_impact', return_value=10), pending_jobs)
+        return pending_jobs
+
+    def test_capacity_exhausted(self, mocker, scheduler_factory, pending_jobs_impactful):
+        scheduler = scheduler_factory(tasks=pending_jobs_impactful)
+
+        scheduler._schedule()
+
+        calls = [mocker.call(job) for job in pending_jobs_impactful]
+        scheduler.start_task.assert_has_calls(calls)
+