First iteration of the offline API client

This is the first iteration of an API client implementation for
interacting with the ARA API.

Change-Id: Ib64f6e535a70d9ec1cfec2cec0d37780fd509be4

ara/clients/offline.py

@@ -0,0 +1,86 @@
+#  Copyright (c) 2018 Red Hat, Inc.
+#
+#  This file is part of ARA: Ansible Run Analysis.
+#
+#  ARA is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  ARA is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with ARA.  If not, see <http://www.gnu.org/licenses/>.
+
+# This is an "offline" API client that does not require standing up
+# an API server and does not execute actual HTTP calls.
+
+import json
+import logging
+import os
+
+from django import setup as django_setup
+from django.core.management import execute_from_command_line
+from django.test import Client
+
+
+class OfflineClient(object):
+    def __init__(self):
+        self.client = self.bootstrap_django_client()
+        self.log = logging.getLogger('ara.clients.offline')
+
+    def _bootstrap_django_client(self):
+        self.log.debug('Bootstrapping Django offline client')
+
+        os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'ara.server.settings')
+        # Automatically create the database and run migrations (is there a better way?)
+        execute_from_command_line(['django', 'migrate'])
+
+        # Set up the things Django needs
+        django_setup()
+
+        return Client()
+
+    def _request(self, method, endpoint, **kwargs):
+        func = getattr(self.client, method)
+        response = func(
+            endpoint,
+            json.dumps(kwargs),
+            content_type='application/json'
+        )
+
+        self.log.debug('HTTP {status}: {method} on {endpoint}'.format(
+            status=response.status_code,
+            method=method,
+            endpoint=endpoint
+        ))
+
+        if response.status_code not in [200, 201]:
+            self.log.error(
+                'Failed to {method} on {endpoint}: {content}'.format(
+                    method=method,
+                    endpoint=endpoint,
+                    content=kwargs
+                )
+            )
+            self.log.fatal(response.content)
+
+        return response.json()
+
+    def get(self, endpoint, **kwargs):
+        return self._request('get', endpoint, **kwargs)
+
+    def patch(self, endpoint, **kwargs):
+        return self._request('patch', endpoint, **kwargs)
+
+    def post(self, endpoint, **kwargs):
+        return self._request('post', endpoint, **kwargs)
+
+    def put(self, endpoint, **kwargs):
+        return self._request('put', endpoint, **kwargs)
+
+    def delete(self, endpoint, **kwargs):
+        return self._request('delete', endpoint, **kwargs)