Add health resource for ucp-integration API convention

It is a UCP API convention to include a health resource in order
for other components to access and validate Deckhand's health status [0].

As such, this PS accomplishes that goal. Also add uwsgi.ini file to
instantiate the webserver using a more complex configuration that
can be overriden more easily.

[0] https://github.com/att-comdev/ucp-integration/blob/master/docs/api-conventions.md#health-check-api

Change-Id: Ice24cec6d0b98c16af62d9436925083d4092a032

README.rst

@@ -23,37 +23,37 @@ Getting Started
 
 To generate a configuration file automatically::
 
-	$ tox -e genconfig
+    $ tox -e genconfig
 
 Resulting deckhand.conf.sample file is output to
 :path:etc/deckhand/deckhand.conf.sample
 
 Copy the config file to a directory discoverably by ``oslo.conf``::
 
-	$ cp etc/deckhand/deckhand.conf.sample ~/deckhand.conf
+    $ cp etc/deckhand/deckhand.conf.sample ~/deckhand.conf
 
 To setup an in-memory database for testing:
 
 .. code-block:: ini
 
-	[database]
+    [database]
 
-	#
-	# From oslo.db
-	#
+    #
+    # From oslo.db
+    #
 
-	# The SQLAlchemy connection string to use to connect to the database.
-	# (string value)
-	connection = sqlite:///:memory:
+    # The SQLAlchemy connection string to use to connect to the database.
+    # (string value)
+    connection = sqlite:///:memory:
 
 To run locally in a development environment::
 
-	$ sudo pip install uwsgi
-	$ virtualenv -p python3 /var/tmp/deckhand
-	$ . /var/tmp/deckhand/bin/activate
-	$ sudo pip install .
-	$ sudo python setup.py install
-	$ uwsgi --http :9000 -w deckhand.cmd --callable deckhand_callable --enable-threads -L
+    $ sudo pip install uwsgi
+    $ virtualenv -p python3 /var/tmp/deckhand
+    $ . /var/tmp/deckhand/bin/activate
+    $ sudo pip install .
+    $ sudo python setup.py install
+    $ uwsgi --ini uwsgi.ini
 
 Testing
 -------

deckhand/control/health.py

@@ -0,0 +1,26 @@
+# Copyright 2017 AT&T Intellectual Property.  All other rights reserved.
+#
+# 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 falcon
+
+from deckhand.control.base import BaseResource
+
+
+class HealthResource(BaseResource):
+    """A resource that allows other UCP components to access and validate
+    Deckhand's health status. The response must be returned within 30 seconds
+    for Deckhand to be deemed "healthy".
+    """
+    def on_get(self, req, resp):
+        resp.status = falcon.HTTP_204

deckhand/service.py

@@ -18,6 +18,7 @@ from oslo_log import log
 
 from deckhand.control import base
 from deckhand.control import buckets
+from deckhand.control import health
 from deckhand.control import middleware
 from deckhand.control import revision_diffing
 from deckhand.control import revision_documents
@@ -35,6 +36,7 @@ def configure_app(app, version=''):
 
     v1_0_routes = [
         ('bucket/{bucket_name}/documents', buckets.BucketsResource()),
+        ('health', health.HealthResource()),
         ('revisions', revisions.RevisionsResource()),
         ('revisions/{revision_id}', revisions.RevisionsResource()),
         ('revisions/{revision_id}/diff/{comparison_revision_id}',

deckhand/tests/unit/control/test_api_initialization.py

@@ -19,6 +19,7 @@ import mock
 
 from deckhand.control import api
 from deckhand.control import buckets
+from deckhand.control import health
 from deckhand.control import revision_diffing
 from deckhand.control import revision_documents
 from deckhand.control import revision_tags
@@ -35,7 +36,7 @@ class TestApi(test_base.DeckhandTestCase):
     def setUp(self):
         super(TestApi, self).setUp()
         # Mock the API resources.
-        for resource in (buckets, revision_diffing, revision_documents,
+        for resource in (buckets, health, revision_diffing, revision_documents,
                          revision_tags, revisions, rollback, validations,
                          versions):
             class_names = self._get_module_class_names(resource)
@@ -75,6 +76,7 @@ class TestApi(test_base.DeckhandTestCase):
         mock_falcon_api.add_route.assert_has_calls([
             mock.call('/api/v1.0/bucket/{bucket_name}/documents',
                       self.buckets_resource()),
+            mock.call('/api/v1.0/health', self.health_resource()),
             mock.call('/api/v1.0/revisions', self.revisions_resource()),
             mock.call('/api/v1.0/revisions/{revision_id}',
                       self.revisions_resource()),

tools/functional-tests.sh

@@ -97,8 +97,6 @@ function gen_paste {
 function gen_policy {
     log_section Creating policy file with liberal permissions
 
-    oslopolicy-sample-generator --config-file=etc/deckhand/policy-generator.conf
-
     policy_file='etc/deckhand/policy.yaml.sample'
     policy_pattern="deckhand\:"
 

uwsgi.ini

@@ -0,0 +1,12 @@
+[uwsgi]
+strict=true
+
+# HTTP
+http=:9000  # Update endpoint as needed.
+http-keepalive=true
+wsgi=deckhand.cmd
+callable=deckhand_callable
+
+# Misc.
+enable-threads=true
+disable-logging=true