Plugable constructors, runners and hooks

Constructors responsible for preparing worker with executor
to be run by runner
Runner acts like a supervisor for executor/executors, in a
simplest scenario it just runs executor in the same thread

Related to blueprint stevedorize-orchestration

Change-Id: If37c3f6be340b7108ac5d672110071238059bd95

setup.cfg

@@ -69,3 +69,16 @@ solar.orchestration.drivers.scheduler =
     solar = solar.orchestration.workers.scheduler:Scheduler
 solar.orchestration.drivers.system_log =
     solar = solar.orchestration.workers.system_log:SystemLog
+solar.orchestration.hooks.tasks.construct =
+    scheduler_sub = solar.orchestration.workers.scheduler:tasks_subscribe
+    system_log_sub = solar.orchestration.workers.system_log:tasks_subscribe
+solar.orchestration.hooks.system_log.construct =
+    session_sub = solar.orchestration:wrap_session
+solar.orchestration.hooks.scheduler.construct =
+    session_sub = solar.orchestration:wrap_session
+solar.orchestration.runners =
+    gevent = solar.orchestration.runners.gevent_runner:run_all
+solar.orchestration.constructors =
+    tasks = solar.orchestration:construct_tasks
+    system_log = solar.orchestration:construct_system_log
+    scheduler = solar.orchestration:construct_scheduler

solar/config.py

@@ -38,6 +38,7 @@ C.executor = 'zerorpc'
 C.tasks_driver = 'solar'
 C.scheduler_driver = 'solar'
 C.system_log_driver = 'solar'
+C.runner = 'gevent'
 
 
 def _lookup_vals(setter, config, prefix=None):

solar/orchestration/__init__.py

@@ -17,58 +17,42 @@ from solar.core.log import log
 from solar.dblayer import ModelMeta
 from solar.orchestration import extensions as loader
 from solar.orchestration.executors import Executor
-from solar.orchestration.workers.scheduler import SchedulerCallbackClient
 
 
 SCHEDULER_CLIENT = loader.get_client('scheduler')
 
 
+def wrap_session(extension, clients):
+    log.debug('DB session for %r', extension)
+    extension.for_all.before(lambda ctxt: ModelMeta.session_start())
+    extension.for_all.after(lambda ctxt: ModelMeta.session_end())
+
+
 def construct_scheduler(extensions, clients):
     scheduler = extensions['scheduler']
+    loader.load_contruct_hooks('scheduler', extensions, clients)
     scheduler_executor = Executor(
         scheduler, clients['scheduler'].connect_to)
-    scheduler.for_all.before(lambda ctxt: ModelMeta.session_start())
-    scheduler.for_all.after(lambda ctxt: ModelMeta.session_end())
     scheduler_executor.run()
 
 
 def construct_system_log(extensions, clients):
     syslog = extensions['system_log']
-    syslog.for_all.before(lambda ctxt: ModelMeta.session_start())
-    syslog.for_all.after(lambda ctxt: ModelMeta.session_end())
+    loader.load_contruct_hooks('system_log', extensions, clients)
     Executor(syslog, clients['system_log'].connect_to).run()
 
 
 def construct_tasks(extensions, clients):
-    syslog = clients['system_log']
-    # FIXME will be solved by hooks on certain events
-    # solar.orchestraion.extensions.tasks.before =
-    #   1 = solar.orchestration.workers.scheduler:subscribe
-    scheduler = SchedulerCallbackClient(clients['scheduler'])
     tasks = extensions['tasks']
+    loader.load_contruct_hooks('tasks', extensions, clients)
     tasks_executor = Executor(tasks, clients['tasks'].connect_to)
     tasks.for_all.before(tasks_executor.register_task)
-    tasks.for_all.on_success(syslog.commit)
-    tasks.for_all.on_error(syslog.error)
-    tasks.for_all.on_success(scheduler.update)
-    tasks.for_all.on_error(scheduler.error)
     tasks_executor.run()
 
 
 def main():
-    import sys
-    from gevent import spawn
-    from gevent import joinall
+    runner = loader.get_runner(C.runner)
+    constructors = loader.get_constructors()
     clients = loader.get_clients()
-    mgr = loader.get_extensions(clients)
-    servers = [
-        spawn(construct_scheduler, mgr, clients),
-        spawn(construct_system_log, mgr, clients),
-        spawn(construct_tasks, mgr, clients)
-        ]
-    try:
-        log.info('Spawning scheduler, system log and tasks workers.')
-        joinall(servers)
-    except KeyboardInterrupt:
-        log.info('Exit solar-worker')
-        sys.exit()
+    exts = loader.get_extensions(clients)
+    runner.driver(constructors, exts, clients)

solar/orchestration/extensions.py

@@ -74,3 +74,23 @@ def get_extensions(clients):
         invoke_on_load=True,
         invoke_args=(clients,))
     return ext
+
+
+def load_contruct_hooks(name, extensions, clients):
+    extension.ExtensionManager(
+        namespace='solar.orchestration.hooks.{}.construct'.format(name),
+        invoke_on_load=True,
+        invoke_args=(extensions[name], clients))
+
+
+def get_runner(name):
+    return driver.DriverManager(
+        namespace='solar.orchestration.runners',
+        name=name,
+        invoke_on_load=False)
+
+
+def get_constructors():
+    return extension.ExtensionManager(
+        namespace='solar.orchestration.constructors',
+        invoke_on_load=False)

solar/orchestration/runners/gevent_runner.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+#    Copyright 2015 Mirantis, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import sys
+
+import gevent
+
+from solar.core.log import log
+
+
+def run_all(construct_manager, extensions, clients):
+
+    def _spawn(constructor, extensions, clients):
+        return gevent.spawn(constructor.plugin, extensions, clients)
+
+    try:
+        log.info('Spawning scheduler, system log and tasks workers.')
+        gevent.joinall(
+            construct_manager.map(_spawn, extensions, clients))
+    except KeyboardInterrupt:
+        log.info('Exit solar-worker')
+        sys.exit()

solar/orchestration/workers/__init__.py

@@ -1,5 +1,4 @@
-#
-# Copyright 2015 Mirantis, Inc.
+#    Copyright 2015 Mirantis, Inc.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
 #    not use this file except in compliance with the License. You may obtain
@@ -12,9 +11,7 @@
 #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 #    License for the specific language governing permissions and limitations
 #    under the License.
-#
 
-from solar.orchestration.workers.scheduler import Scheduler
-from solar.orchestration.workers.scheduler import SchedulerCallbackClient
-from solar.orchestration.workers.system_log import SystemLog
-from solar.orchestration.workers.tasks import Tasks
+import solar.orchestration.workers.scheduler
+import solar.orchestration.workers.system_log
+import solar.orchestration.workers.tasks

solar/orchestration/workers/scheduler.py

@@ -140,3 +140,10 @@ class SchedulerCallbackClient(object):
 
     def error(self, ctxt, result, *args, **kwargs):
         self.client.update_next(ctxt, states.ERROR.name, repr(result))
+
+
+def tasks_subscribe(tasks, clients):
+    log.debug('Scheduler subscribes to tasks hooks')
+    scheduler = SchedulerCallbackClient(clients['scheduler'])
+    tasks.for_all.on_success(scheduler.update)
+    tasks.for_all.on_error(scheduler.error)

solar/orchestration/workers/system_log.py

@@ -12,6 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from solar.core.log import log
 from solar.orchestration.workers import base
 from solar.system_log.operations import move_to_commited
 from solar.system_log.operations import set_error
@@ -24,3 +25,10 @@ class SystemLog(base.Worker):
 
     def error(self, ctxt, *args, **kwargs):
         return set_error(ctxt['task_id'].rsplit(':', 1)[-1])
+
+
+def tasks_subscribe(tasks, clients):
+    log.debug('System log subscribes to tasks hooks')
+    syslog = clients['system_log']
+    tasks.for_all.on_success(syslog.commit)
+    tasks.for_all.on_error(syslog.error)

solar/test/functional/conftest.py

@@ -18,7 +18,7 @@ import string
 import gevent
 import pytest
 
-
+from solar.config import C
 from solar.core.log import log
 from solar.dblayer.model import ModelMeta
 from solar.orchestration import executors
@@ -104,3 +104,13 @@ def clients(request):
 @pytest.fixture
 def extensions(clients):
     return loader.get_extensions(clients)
+
+
+@pytest.fixture
+def runner():
+    return loader.get_runner(C.runner)
+
+
+@pytest.fixture
+def constructors():
+    return loader.get_constructors()

solar/test/functional/test_complete_solar_workflow.py

@@ -33,24 +33,9 @@ def scheduler_client(scheduler_address):
 
 
 @pytest.fixture(autouse=True)
-def tasks(extensions, clients):
-    gevent.spawn(
-        orchestration.construct_tasks,
-        extensions, clients)
-
-
-@pytest.fixture(autouse=True)
-def scheduler(extensions, clients):
-    gevent.spawn(
-        orchestration.construct_scheduler,
-        extensions, clients)
-
-
-@pytest.fixture(autouse=True)
-def system_log(extensions, clients):
-    gevent.spawn(
-        orchestration.construct_system_log,
-        extensions, clients)
+def prepare_all(constructors, extensions, clients):
+    for cons in constructors:
+        gevent.spawn(cons.plugin, extensions, clients)
 
 
 @pytest.fixture(autouse=True)
@@ -61,7 +46,7 @@ def resources(request, sequence_vr):
             'sequence_%s' % idx, sequence_vr, inputs={'idx': idx})
 
 
-@pytest.mark.parametrize('scale', [10])
+@pytest.mark.parametrize('scale', [3])
 def test_concurrent_sequences_with_no_handler(scale, clients):
     total_resources = scale * 3
     timeout = scale * 2