Bug 1415868 - add 'mach taskgraph actions'; r=jonasfj,tomprince

MozReview-Commit-ID: ExVRgcD02GK

taskcluster/docs/actions.rst

@@ -34,6 +34,11 @@ a custom action task can be more efficient.
 
 Creating a Callback Action
 --------------------------
+
+.. note:
+
+    You can generate ``actions.json`` on the command line with ``./mach taskgraph actions``.
+
 A *callback action* is an action that calls back into in-tree logic. That is,
 you register the action with name, title, description, context, input schema and a
 python callback. When the action is triggered in a user interface,

taskcluster/mach_commands.py

@@ -103,6 +103,20 @@ class MachCommands(MachCommandBase):
     def taskgraph_morphed(self, **options):
         return self.show_taskgraph('morphed_task_graph', options)
 
+    @SubCommand('taskgraph', 'actions',
+                description="Write actions.json to stdout")
+    @CommandArgument('--root', '-r',
+                     help="root of the taskgraph definition relative to topsrcdir")
+    @CommandArgument('--quiet', '-q', action="store_true",
+                     help="suppress all logging output")
+    @CommandArgument('--verbose', '-v', action="store_true",
+                     help="include debug-level logging output")
+    @CommandArgument('--parameters', '-p', default="project=mozilla-central",
+                     help="parameters file (.yml or .json; see "
+                          "`taskcluster/docs/parameters.rst`)`")
+    def taskgraph_actions(self, **options):
+        return self.show_actions(options)
+
     @SubCommand('taskgraph', 'decision',
                 description="Run the decision task")
     @CommandArgument('--root', '-r',
@@ -385,6 +399,28 @@ class MachCommands(MachCommandBase):
         filtered_taskgraph = TaskGraph(filteredtasks, Graph(set(filteredtasks), filterededges))
         return filtered_taskgraph
 
+    def show_actions(self, options):
+        import taskgraph.parameters
+        import taskgraph.target_tasks
+        import taskgraph.generator
+        import taskgraph
+        import taskgraph.actions
+
+        try:
+            self.setup_logging(quiet=options['quiet'], verbose=options['verbose'])
+            parameters = taskgraph.parameters.load_parameters_file(options['parameters'])
+            parameters.check()
+
+            tgg = taskgraph.generator.TaskGraphGenerator(
+                root_dir=options.get('root'),
+                parameters=parameters)
+
+            actions = taskgraph.actions.render_actions_json(parameters, tgg.graph_config)
+            print(json.dumps(actions, sort_keys=True, indent=2, separators=(',', ': ')))
+        except Exception:
+            traceback.print_exc()
+            sys.exit(1)
+
 
 @CommandProvider
 class TaskClusterImagesProvider(MachCommandBase):