Aggregator configuration API methods

.gitignore

@@ -8,4 +8,6 @@ ubuntu-xenial-16.04-cloudimg-console.log
 .idea/
 *.egg
 *.pyc
+.pytest_cache
+.tox
 *$py.class

CLMCservice/__init__.py

 from pyramid.config import Configurator
+from pyramid.settings import asbool
+from CLMCservice.views import AggregatorConfig
 
 
 def main(global_config, **settings):
     """ This function returns a Pyramid WSGI application."""
 
+    # a conversion is necessary so that the configuration value of the aggregator is stored as bool and not as string
+    aggregator_running = asbool(settings.get('aggregator_running', 'false'))
+    settings['aggregator_running'] = aggregator_running
+
     config = Configurator(settings=settings)
-    config.add_route('home', '/')
+
+    config.add_route('aggregator', '/aggregator')
+    config.add_view(AggregatorConfig, attr='get', request_method='GET')
+    config.add_view(AggregatorConfig, attr='post', request_method='POST')
+
     config.scan()
     return config.make_wsgi_app()

CLMCservice/tests.py

-# Specific tests related to the CLMC service
\ No newline at end of file
+import pytest
+from pyramid import testing
+from pyramid.httpexceptions import HTTPBadRequest
+
+
+class TestAggregatorConfig(object):
+    """
+    A pytest-implementation test for the aggregator configuration API calls
+    """
+
+    @pytest.fixture(autouse=True)
+    def app_config(self):
+        """
+        A fixture to implement setUp/tearDown functionality for all tests by initializing configuration structure for the web service
+        """
+
+        self.config = testing.setUp()
+        self.config.add_settings({'aggregator_running': False})
+
+        yield
+
+        testing.tearDown()
+
+    def test_GET(self):
+        """
+        Tests the GET method for the status of the aggregator.
+        """
+
+        from CLMCservice.views import AggregatorConfig  # nested import so that importing the class view is part of the test itself
+
+        assert not self.config.get_settings().get('aggregator_running'), "Initially aggregator is not running."
+
+        request = testing.DummyRequest()
+        response = AggregatorConfig(request).get()
+
+        assert type(response) == dict, "Response must be a dictionary representing a JSON object."
+        assert not response.get('aggregator_running'), "The response of the API call must return the aggregator status being set as False"
+        assert not self.config.get_settings().get('aggregator_running'), "A GET request must not modify the aggregator status."
+
+    @pytest.mark.parametrize("input_val, output_val", [
+        ("True", True),
+        ("true", True),
+        ("1", True),
+        ("False", False),
+        ("false", False),
+        ("0", False),
+        ("t", None),
+        ("f", None),
+    ])
+    def test_POST(self, input_val, output_val):
+        """
+        Tests the POST method for the status of the aggregator
+        :param input_val: the input form parameter
+        :param output_val: the expected output value, None for expecting an Exception
+        """
+
+        from CLMCservice.views import AggregatorConfig  # nested import so that importing the class view is part of the test itself
+
+        assert not self.config.get_settings().get('aggregator_running'), "Initially aggregator is not running."
+
+        request = testing.DummyRequest()
+
+        request.params['running'] = input_val
+        if output_val is not None:
+            response = AggregatorConfig(request).post()
+            assert response == {'aggregator_running': output_val}, "Response of POST request must include the new status of the aggregator"
+            assert self.config.get_settings().get('aggregator_running') == output_val, "Aggregator status must be updated to running."
+        else:
+            error_raised = False
+            try:
+                AggregatorConfig(request).post()
+            except HTTPBadRequest:
+                error_raised = True
+
+            assert error_raised, "Error must be raised in case of an invalid argument."

CLMCservice/utilities.py

+def str_to_bool(value):
+    """
+    A utility function to convert a string to boolean based on simple rules.
+    :param value: the value to convert
+    :return: True or False
+    :raises ValueError: if value cannot be converted to boolean
+    """
+
+    if type(value) is not str:
+        raise ValueError("This method only converts string to booolean.")
+
+    if value in ('False', 'false', '0'):
+        return False
+    elif value in ('True', 'true', '1'):
+        return True
+    else:
+        raise ValueError("Invalid argument for conversion")

CLMCservice/views.py

-from pyramid.view import view_config
-from pyramid.response import Response
+from pyramid.view import view_defaults
+from pyramid.httpexceptions import HTTPBadRequest
 
+from CLMCservice.utilities import str_to_bool
 
-@view_config(route_name='home')
-def my_view(request):
-    return Response("Hello world")
+
+@view_defaults(route_name='aggregator', renderer='json')
+class AggregatorConfig(object):
+    """
+    A class-based view for accessing and mutating the status of the aggregator.
+    """
+
+    def __init__(self, request):
+        """
+        Initialises the instance of the view with the request argument.
+        :param request: client's call request
+        """
+
+        self.request = request
+
+    def get(self):
+        """
+        A GET API call for the status of the aggregator.
+        :return: A JSON response with the status of the aggregator.
+        """
+
+        aggregator_running = self.request.registry.settings.get('aggregator_running')
+        return {'aggregator_running': aggregator_running}
+
+    def post(self):
+        """
+        A POST API call for the status of the aggregator.
+        :return: A JSON response to the POST call (success or fail).
+        :raises HTTPBadRequest: if form argument cannot be converted to boolean
+        """
+
+        new_status = self.request.params.get('running')
+
+        try:
+            new_status = str_to_bool(new_status)
+        except ValueError:
+            raise HTTPBadRequest("Bad request parameter - expected a boolean, received {0}".format(self.request.params.get('running')))
+
+        self.request.registry.settings['aggregator_running'] = new_status
+        # TODO start/stop aggregator based on value of new status
+        return {'aggregator_running': new_status}

production.ini

@@ -11,6 +11,7 @@ pyramid.debug_authorization = false
 pyramid.debug_notfound = false
 pyramid.debug_routematch = false
 pyramid.default_locale_name = en
+aggregator_running = false
 
 ###
 # wsgi server configuration