Bug 1525736: [taskgraph] Allow looking up parameters by project for trust-domains other than `gecko`; r=dustin

Previously, this code looked parameters under `gecko.v2`, but that doesn't work
for projects using the out-of-tree taskgraph code, or Thunderbird. This moves
the parameter loading slightly later to vary the index used based on trust domain.

Differential Revision: https://phabricator.services.mozilla.com/D19028

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

taskcluster/mach_commands.py

@@ -299,7 +299,12 @@ class MachCommands(MachCommandBase):
             else:
                 input = None
 
-            parameters = taskgraph.parameters.load_parameters_file(options['parameters'])
+            parameters = taskgraph.parameters.load_parameters_file(
+                options['parameters'],
+                strict=False,
+                # FIXME: There should be a way to parameterize this.
+                trust_domain="gecko",
+            )
             parameters.check()
 
             root = options['root']
@@ -345,8 +350,7 @@ class MachCommands(MachCommandBase):
 
         try:
             self.setup_logging(quiet=options['quiet'], verbose=options['verbose'])
-            parameters = taskgraph.parameters.load_parameters_file(options['parameters'])
-            parameters.check()
+            parameters = taskgraph.parameters.parameters_loader(options['parameters'])
 
             tgg = taskgraph.generator.TaskGraphGenerator(
                 root_dir=options.get('root'),
@@ -404,14 +408,13 @@ class MachCommands(MachCommandBase):
 
         try:
             self.setup_logging(quiet=options['quiet'], verbose=options['verbose'])
-            parameters = taskgraph.parameters.load_parameters_file(options['parameters'])
-            parameters.check()
+            parameters = taskgraph.parameters.parameters_loader(options['parameters'])
 
             tgg = taskgraph.generator.TaskGraphGenerator(
                 root_dir=options.get('root'),
                 parameters=parameters)
 
-            actions = taskgraph.actions.render_actions_json(parameters, tgg.graph_config)
+            actions = taskgraph.actions.render_actions_json(tgg.parameters, tgg.graph_config)
             print(json.dumps(actions, sort_keys=True, indent=2, separators=(',', ': ')))
         except Exception:
             traceback.print_exc()

taskcluster/taskgraph/parameters.py

@@ -185,7 +185,7 @@ class Parameters(ReadOnlyDict):
         return release_level(self['project'])
 
 
-def load_parameters_file(filename, strict=True, overrides=None):
+def load_parameters_file(filename, strict=True, overrides=None, trust_domain=None):
     """
     Load parameters from a path, url, decision task-id or project.
 
@@ -212,7 +212,13 @@ def load_parameters_file(filename, strict=True, overrides=None):
         if filename.startswith("task-id="):
             task_id = filename.split("=")[1]
         elif filename.startswith("project="):
-            index = "gecko.v2.{project}.latest.taskgraph.decision".format(
+            if trust_domain is None:
+                raise ValueError(
+                    "Can't specify parameters by project "
+                    "if trust domain isn't supplied.",
+                )
+            index = "{trust_domain}.v2.{project}.latest.taskgraph.decision".format(
+                trust_domain=trust_domain,
                 project=filename.split("=")[1],
             )
             task_id = find_task_id(index)
@@ -231,3 +237,16 @@ def load_parameters_file(filename, strict=True, overrides=None):
     kwargs.update(overrides)
 
     return Parameters(strict=strict, **kwargs)
+
+
+def parameters_loader(filename, strict=True, overrides=None):
+    def get_parameters(graph_config):
+        parameters = load_parameters_file(
+            filename,
+            strict=strict,
+            overrides=overrides,
+            trust_domain=graph_config["trust-domain"],
+        )
+        parameters.check()
+        return parameters
+    return get_parameters

tools/tryselect/tasks.py

@@ -22,7 +22,7 @@ import taskgraph
 from taskgraph.generator import TaskGraphGenerator
 from taskgraph.parameters import (
     ParameterMismatch,
-    load_parameters_file,
+    parameters_loader,
 )
 from taskgraph.taskgraph import TaskGraph
 
@@ -81,19 +81,18 @@ def generate_tasks(params, full, root):
         os.makedirs(cache_dir)
 
     print("Task configuration changed, generating {}".format(attr.replace('_', ' ')))
-    try:
-        params = load_parameters_file(params, strict=False, overrides={'try_mode': 'try_select'})
-        params.check()
-    except ParameterMismatch as e:
-        print(PARAMETER_MISMATCH.format(e.args[0]))
-        sys.exit(1)
 
     taskgraph.fast = True
     cwd = os.getcwd()
     os.chdir(build.topsrcdir)
 
     root = os.path.join(root, 'taskcluster', 'ci')
-    tg = getattr(TaskGraphGenerator(root_dir=root, parameters=params), attr)
+    params = parameters_loader(params, strict=False, overrides={'try_mode': 'try_select'})
+    try:
+        tg = getattr(TaskGraphGenerator(root_dir=root, parameters=params), attr)
+    except ParameterMismatch as e:
+        print(PARAMETER_MISMATCH.format(e.args[0]))
+        sys.exit(1)
 
     os.chdir(cwd)