Bug 1899878 - Add a lull-schedule attribute to some browsertime tasks. r=kshampur,perftest-reviewers DONTBUILD

This patch adds a lull-schedule attribute to some browsertime live-site tasks so that we can start testing lull-scheduling. The lull-schedule attribute will be used to denote how frequently a particular task should run. The lull-schedule attribute exists first as a raptor specific setting, and is then added to the `extra` section so that we can make use of it in the `mozci` module.

Differential Revision: https://phabricator.services.mozilla.com/D212202

taskcluster/docs/attributes.rst

@@ -529,5 +529,8 @@ Used by android browsertime tasks to track the path to the apk of the product un
 
 test-manifests
 ==============
-
 A list of the test manifests that run in this task.
+
+lull-schedule
+=============
+Used by performance tasks to schedule them at a specified frequency in a best-effort method. Schedules them when the overall CI load is low for a given platform. Use "w" for weeks, "d" for days, "h" for hours, and "m" for minutes in a string like so to specify the scheduling frequency: 1d, 1w 4h, 2w 4d 1h.

taskcluster/gecko_taskgraph/transforms/test/raptor.py

@@ -30,6 +30,9 @@ raptor_description_schema = Schema(
             Optional("test-url-param"): optionally_keyed_by(
                 "subtest", "test-platform", str
             ),
+            Optional("lull-schedule"): optionally_keyed_by(
+                "subtest", "test-platform", str
+            ),
         },
         # Configs defined in the 'test_description_schema'.
         Optional("max-run-time"): optionally_keyed_by(
@@ -163,6 +166,7 @@ def handle_keyed_by(config, tests):
         "raptor.run-visual-metrics",
         "raptor.activity",
         "raptor.binary-path",
+        "raptor.lull-schedule",
         "limit-platforms",
         "fetches.fetch",
         "max-run-time",
@@ -339,6 +343,18 @@ def modify_mozharness_configs(config, tests):
         yield test
 
 
+@transforms.add
+def handle_lull_schedule(config, tests):
+    # Setup lull schedule attribute here since the attributes
+    # can't have any keyed by settings
+    for test in tests:
+        if "lull-schedule" in test["raptor"]:
+            lull_schedule = test["raptor"].pop("lull-schedule")
+            if lull_schedule:
+                test.setdefault("attributes", {})["lull-schedule"] = lull_schedule
+        yield test
+
+
 @task_transforms.add
 def add_scopes_and_proxy(config, tasks):
     for task in tasks:
@@ -347,3 +363,15 @@ def add_scopes_and_proxy(config, tasks):
             "secrets:get:project/perftest/gecko/level-{level}/perftest-login"
         )
         yield task
+
+
+@task_transforms.add
+def setup_lull_schedule(config, tasks):
+    for task in tasks:
+        attrs = task.setdefault("attributes", {})
+        if attrs.get("lull-schedule", None) is not None:
+            # Move the lull schedule attribute into the extras
+            # so that it can be accessible through mozci
+            lull_schedule = attrs.pop("lull-schedule")
+            task.setdefault("extra", {})["lull-schedule"] = lull_schedule
+        yield task

taskcluster/kinds/test/browsertime-desktop.yml

@@ -659,6 +659,10 @@ browsertime-tp6-live:
         apps: [firefox, chrome, safari]
         test: tp6
         run-visual-metrics: true
+        lull-schedule:
+            by-test-platform:
+                .*shippable.*: 1w
+                default: ""
         subtests:
             by-app:
                 safari: