Bug 1603463 - Implement |mach try auto| which selects tasks on try automatically, r=tomprince

The 'auto' in 'mach try auto' stands for two things:

1. It automatically picks tasks for you.
2. It runs the same scheduling algorithms as autoland.

It accomplishes this by creating a new target_tasks method that spoofs the
'project' parameter to autoland.

Differential Revision: https://phabricator.services.mozilla.com/D60184

--HG--
extra : moz-landing-system : lando

taskcluster/docs/parameters.rst

@@ -86,11 +86,13 @@ Try Configuration
 -----------------
 
 ``try_mode``
-    The mode in which a try push is operating.  This can be one of
-    ``"try_task_config"``, ``"try_option_syntax"``, ``"try_select"`` or ``None`` meaning no try
-    input was provided.
+   The mode in which a try push is operating.  This can be one of:
 
-    ``"try_select"`` is used by ``mach try fuzzy`` to build a list of tasks to select from.
+    * ``"try_task_config"`` - Used to configure the taskgraph.
+    * ``"try_option_syntax"`` - Used when pushing to try with legacy try syntax.
+    * ``"try_auto"`` - Used to make try pushes behave more like a push on ``autoland``.
+    * ``"try_select"`` - Used by ``mach try`` to build a list of tasks locally.
+    * ``None`` - Not a try push or ``mach try release``.
 
 ``try_options``
     The arguments given as try syntax (as a dictionary), or ``None`` if
@@ -194,19 +196,19 @@ Repository Merge Day
 
 ``source_repo``
    The clone/push URI of the source repository, such as https://hg.mozilla.org/mozilla-central
- 
+
 ``target_repo``
    The clone/push URI of the target repository, such as https://hg.mozilla.org/releases/mozilla-beta
- 
+
 ``source_branch``
    The firefoxtree alias of the source branch, such as 'central', 'beta'
- 
+
 ``target_branch``
    The firefoxtree alias of the target branch, such as 'beta', 'release'
 
 ``force-dry-run``
    Don't push any results to target repositories.
- 
+
 
 Comm Push Information
 ---------------------

taskcluster/taskgraph/optimize/seta.py

@@ -18,7 +18,7 @@ from taskgraph.optimize import OptimizationStrategy, register_strategy
 logger = logging.getLogger(__name__)
 
 # It's a list of project name which SETA is useful on
-SETA_PROJECTS = ['autoland']
+SETA_PROJECTS = ['autoland', 'try']
 SETA_HIGH_PRIORITY = 1
 SETA_LOW_PRIORITY = 5
 
@@ -234,18 +234,24 @@ class SETA(object):
         if project not in SETA_PROJECTS:
             return False
 
-        # on every Nth push, want to run all tasks
-        if int(pushlog_id) % push_interval == 0:
-            return False
+        # Disable the "run all tasks" feature if we're on try (e.g pushed via `mach try auto`)
+        if project != 'try':
+            # on every Nth push, want to run all tasks
+            if int(pushlog_id) % push_interval == 0:
+                return False
 
-        # Nth push, so time to call seta based on number of pushes; however
-        # we also want to ensure we run all tasks at least once per N minutes
-        if self.minutes_between_pushes(
-                project,
-                int(pushlog_id),
-                int(push_date),
-                time_interval) >= time_interval:
-            return False
+            # Nth push, so time to call seta based on number of pushes; however
+            # we also want to ensure we run all tasks at least once per N minutes
+            if self.minutes_between_pushes(
+                    project,
+                    int(pushlog_id),
+                    int(push_date),
+                    time_interval) >= time_interval:
+                return False
+
+        else:
+            # The SETA service has a superficial check preventing try, so spoof autoland
+            project = 'autoland'
 
         # cache the low value tasks per project to avoid repeated SETA server queries
         if project not in self.low_value_tasks:

taskcluster/taskgraph/target_tasks.py

@@ -7,6 +7,7 @@
 from __future__ import absolute_import, print_function, unicode_literals
 
 from taskgraph import try_option_syntax
+from taskgraph.parameters import Parameters
 from taskgraph.util.attributes import match_run_on_projects, match_run_on_hg_branches
 
 _target_task_methods = {}
@@ -171,6 +172,21 @@ def target_tasks_try(full_task_graph, parameters, graph_config):
         return []
 
 
+@_target_task('try_auto')
+def target_tasks_try_auto(full_task_graph, parameters, graph_config):
+    """Target the tasks which have indicated they should be run on autoland
+    (rather than try) via the `run_on_projects` attributes.
+
+    Should do the same thing as the `default` target tasks method.
+    """
+    params = dict(parameters)
+    params['project'] = 'autoland'
+    parameters = Parameters(**params)
+    return [l for l, t in full_task_graph.tasks.iteritems()
+            if standard_filter(t, parameters)
+            and filter_out_nightly(t, parameters)]
+
+
 @_target_task('default')
 def target_tasks_default(full_task_graph, parameters, graph_config):
     """Target the tasks which have indicated they should be run on this project

taskcluster/taskgraph/transforms/build.py

@@ -177,13 +177,10 @@ def enable_full_crashsymbols(config, jobs):
 
 @transforms.add
 def use_artifact(config, jobs):
-    if config.params['try_mode'] == 'try_task_config':
-        use_artifact = config.params['try_task_config'] \
-            .get('use-artifact-builds', False)
-    elif config.params['try_mode'] == 'try_option_syntax':
+    if config.params['try_mode'] == 'try_option_syntax':
         use_artifact = config.params['try_options'].get('artifact')
     else:
-        use_artifact = False
+        use_artifact = config.params['try_task_config'].get('use-artifact-builds', False)
     for job in jobs:
         if (config.kind == 'build' and use_artifact and
             not job.get('attributes', {}).get('nightly', False) and

taskcluster/taskgraph/transforms/tests.py

@@ -1584,7 +1584,8 @@ def make_job_description(config, tests):
             jobdesc['when'] = test['when']
         elif 'optimization' in test:
             jobdesc['optimization'] = test['optimization']
-        elif config.params.is_try():
+        # Pushes generated by `mach try auto` should use the non-try optimizations.
+        elif config.params.is_try() and config.params['try_mode'] != 'try_auto':
             jobdesc['optimization'] = {'test-try': schedules}
         elif category in INCLUSIVE_COMPONENTS:
             jobdesc['optimization'] = {'test-inclusive': schedules}

tools/tryselect/mach_commands.py

@@ -325,6 +325,14 @@ class TrySelect(MachCommandBase):
 
         return self.run(**kwargs)
 
+    @SubCommand('try',
+                'auto',
+                description='Automatically determine which tasks to run. This runs the same '
+                            'set of tasks that would be run on autoland.',
+                parser=get_parser('auto'))
+    def try_auto(self, **kwargs):
+        return self.run(**kwargs)
+
     @SubCommand('try',
                 'again',
                 description='Schedule a previously generated (non try syntax) '

tools/tryselect/selectors/auto.py

@@ -0,0 +1,35 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+from ..cli import BaseTryParser
+from ..push import push_to_try
+
+
+class AutoParser(BaseTryParser):
+    name = 'auto'
+    common_groups = ['push']
+    task_configs = [
+        "artifact",
+        "env",
+        "chemspill-prio",
+        "disable-pgo",
+        "worker-overrides",
+    ]
+
+
+def run(message='{msg}', push=True, closed_tree=False, try_config=None):
+    msg = message.format(msg='Tasks automatically selected.')
+    task_config = {
+        'version': 2,
+        'parameters': {
+            'optimize_target_tasks': True,
+            'target_tasks_method': 'try_auto',
+            'try_mode': 'try_auto',
+            'try_task_config': try_config or {},
+        }
+    }
+    return push_to_try('auto', msg, try_task_config=task_config,
+                       push=push, closed_tree=closed_tree)

tools/tryselect/test/cram.ini

@@ -1,3 +1,4 @@
+[test_auto.t]
 [test_empty.t]
 [test_fuzzy.t]
 [test_message.t]

tools/tryselect/test/test_auto.t

@@ -0,0 +1,55 @@
+
+  $ . $TESTDIR/setup.sh
+  $ cd $topsrcdir
+
+Test auto selector
+
+  $ ./mach try auto --no-push
+  Commit message:
+  Tasks automatically selected.
+  
+  Pushed via `mach try auto`
+  Calculated try_task_config.json:
+  {
+      "parameters": {
+          "optimize_target_tasks": true,
+          "target_tasks_method": "try_auto",
+          "try_mode": "try_auto",
+          "try_task_config": {}
+      },
+      "version": 2
+  }
+  
+
+  $ ./mach try auto --no-push --closed-tree
+  Commit message:
+  Tasks automatically selected. ON A CLOSED TREE
+  
+  Pushed via `mach try auto`
+  Calculated try_task_config.json:
+  {
+      "parameters": {
+          "optimize_target_tasks": true,
+          "target_tasks_method": "try_auto",
+          "try_mode": "try_auto",
+          "try_task_config": {}
+      },
+      "version": 2
+  }
+  
+  $ ./mach try auto --no-push --closed-tree -m "foo {msg} bar"
+  Commit message:
+  foo Tasks automatically selected. bar ON A CLOSED TREE
+  
+  Pushed via `mach try auto`
+  Calculated try_task_config.json:
+  {
+      "parameters": {
+          "optimize_target_tasks": true,
+          "target_tasks_method": "try_auto",
+          "try_mode": "try_auto",
+          "try_task_config": {}
+      },
+      "version": 2
+  }
+