Bug 1414919 - [taskgraph] Create a 'rebuild' morph template, r=dustin

This template takes a single integer as input, and sets the 'task_duplicates'
attribute on any tasks that were explicitly specified by try_task_config.json.
This means dependent tasks or 'always_target' tasks will not be rebuilt.

To support this template, the apply_jsone_templates morph now requires the
entire try_task_config object instead of just the templates.

MozReview-Commit-ID: DwxUtlC5VD5

--HG--
extra : rebase_source : c57a80ada2fc4591a5ce4c94965b8c9f02bb53b1

taskcluster/docs/try.rst

@@ -114,6 +114,8 @@ The context available to the JSON-e render contains attributes from the
     {
       "attributes": task.attributes,
       "kind": task.kind,
+      "label": task.label,
+      "target_tasks": [<tasks from try_task_config.json>],
       "task": task.task,
       "taskId": task.task_id,
       "input": ...

taskcluster/taskgraph/morph.py

@@ -253,8 +253,9 @@ class apply_jsone_templates(object):
     """
     template_dir = os.path.join(here, 'templates')
 
-    def __init__(self, templates):
-        self.templates = templates
+    def __init__(self, try_task_config):
+        self.templates = try_task_config.get('templates')
+        self.target_tasks = try_task_config.get('tasks')
 
     def __call__(self, taskgraph, label_to_taskid):
         if not self.templates:
@@ -270,6 +271,8 @@ class apply_jsone_templates(object):
                     'input': self.templates[template],
                     # The following context differs from action tasks
                     'attributes': task.attributes,
+                    'label': task.label,
+                    'target_tasks': self.target_tasks,
                 }
 
                 template_path = os.path.join(self.template_dir, template + '.yml')
@@ -290,7 +293,7 @@ def morph(taskgraph, label_to_taskid, parameters):
         add_s3_uploader_task,
     ]
     if parameters['try_mode'] == 'try_task_config':
-        morphs.append(apply_jsone_templates(parameters['try_task_config'].get('templates')))
+        morphs.append(apply_jsone_templates(parameters['try_task_config']))
 
     for m in morphs:
         taskgraph, label_to_taskid = m(taskgraph, label_to_taskid)

taskcluster/taskgraph/templates/rebuild.yml

@@ -0,0 +1,8 @@
+---
+$if: label in target_tasks
+then:
+    attributes:
+        $merge:
+            - $eval: attributes
+            - task_duplicates:
+                $eval: input

taskcluster/taskgraph/test/test_morph.py

@@ -138,7 +138,12 @@ class TestApplyJSONeTemplates(MorphTestCase):
             t['label']: Task(**t) for t in self.tasks[:]
         })
 
-        fn = morph.apply_jsone_templates({'artifact': {'enabled': 1}})
+        try_task_config = {
+            'templates': {
+                'artifact': {'enabled': 1}
+            },
+        }
+        fn = morph.apply_jsone_templates(try_task_config)
         morphed = fn(tg, label_to_taskid)[0]
 
         self.assertEqual(len(morphed.tasks), 2)
@@ -158,7 +163,15 @@ class TestApplyJSONeTemplates(MorphTestCase):
             t['label']: Task(**t) for t in self.tasks[:]
         })
 
-        fn = morph.apply_jsone_templates({'env': {'ENABLED': 1, 'FOO': 'BAZ'}})
+        try_task_config = {
+            'templates': {
+                'env': {
+                    'ENABLED': 1,
+                    'FOO': 'BAZ',
+                }
+            },
+        }
+        fn = morph.apply_jsone_templates(try_task_config)
         morphed = fn(tg, label_to_taskid)[0]
 
         self.assertEqual(len(morphed.tasks), 2)
@@ -167,7 +180,10 @@ class TestApplyJSONeTemplates(MorphTestCase):
             self.assertEqual(t.task['payload']['env']['ENABLED'], 1)
             self.assertEqual(t.task['payload']['env']['FOO'], 'BAZ')
 
-        fn = morph.apply_jsone_templates({'env': {'ENABLED': 0}})
+        try_task_config['templates']['env'] = {
+            'ENABLED': 0,
+        }
+        fn = morph.apply_jsone_templates(try_task_config)
         morphed = fn(tg, label_to_taskid)[0]
 
         self.assertEqual(len(morphed.tasks), 2)
@@ -176,6 +192,28 @@ class TestApplyJSONeTemplates(MorphTestCase):
             self.assertEqual(t.task['payload']['env']['ENABLED'], 0)
             self.assertEqual(t.task['payload']['env']['FOO'], 'BAZ')
 
+    def test_template_rebuild(self):
+        tg, label_to_taskid = self.make_taskgraph({
+            t['label']: Task(**t) for t in self.tasks[:]
+        })
+
+        try_task_config = {
+            'tasks': ['b'],
+            'templates': {
+                'rebuild': 4,
+            },
+        }
+        fn = morph.apply_jsone_templates(try_task_config)
+        tasks = fn(tg, label_to_taskid)[0].tasks.values()
+        self.assertEqual(len(tasks), 2)
+
+        for t in tasks:
+            if t.label == 'a':
+                self.assertNotIn('task_duplicates', t.attributes)
+            elif t.label == 'b':
+                self.assertIn('task_duplicates', t.attributes)
+                self.assertEqual(t.attributes['task_duplicates'], 4)
+
 
 if __name__ == '__main__':
     main()