Add test_memory

- Add a script that runs test MBS instance.
- Add memory tracking test-case.
- New tox environment: run with 'tox -e memory'.

tests/test_memory/mbs_debug.py

@@ -0,0 +1,70 @@
+from __future__ import absolute_import, print_function
+
+import koji
+import mock
+import signal
+import threading
+import types
+
+from module_build_service import app
+from module_build_service.common import conf
+from module_build_service.builder import GenericBuilder
+
+from tests.test_build.test_build import FakeModuleBuilder
+from tests.test_build.test_build import main as run_scheduler
+
+
+def patch_config_system_setter():
+    """bypass supported builders check"""
+    def set_system(self, system):
+        self._system = system
+    conf._setifok_system = types.MethodType(set_system, conf)
+
+
+def register_fake_builder():
+    patch_config_system_setter()
+    conf.system = FakeModuleBuilder.backend
+    GenericBuilder.register_backend_class(FakeModuleBuilder)
+
+    # Builder always instantly succeeds
+    def on_get_task_info_cb(cls, task_id):
+        return {"state": koji.TASK_STATES["CLOSED"]}
+    FakeModuleBuilder.on_get_task_info_cb = on_get_task_info_cb
+
+
+class SimpleMock:
+    """Dummy callable mock object - we want our memory footprint to be as small as possible"""
+    def __call__(self, *args, **kwargs):
+        return True
+
+
+@mock.patch("module_build_service.scheduler.handlers.modules.handle_stream_collision_modules",
+            new_callable=SimpleMock)
+@mock.patch("module_build_service.scheduler.handlers.modules.record_module_build_arches",
+            new_callable=SimpleMock)
+@mock.patch("module_build_service.scheduler.greenwave.Greenwave.check_gating",
+            new_callable=SimpleMock)
+def run_debug_instance(mock_1, mock_2, mock_3, host=None, port=None):
+
+    def handle_pdb(sig, frame):
+        import pdb
+        pdb.Pdb().set_trace(frame)
+
+    # kill -10 <PID> to start debugger
+    signal.signal(signal.SIGUSR1, handle_pdb)
+
+    register_fake_builder()
+
+    host = host or conf.host
+    port = port or conf.port
+
+    def run_app():
+        app.run(host=host, port=port, debug=False)
+    threading.Thread(target=run_app, daemon=True).start()
+
+    # run moksha hub and never stop
+    run_scheduler([], stop_condition=lambda msg: False)
+
+
+if __name__ == '__main__':
+    run_debug_instance()