Experimental wsgi support

Added experimental wsgi support. This is largley untested,
but should be functional.

Change-Id: I079702a4fd7547b1fb577f4e231863df3ed90adf

designate/api/wsgi.py

@@ -0,0 +1,60 @@
+#    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.
+"""WSGI script for Designate API."""
+
+import eventlet  # noqa
+
+eventlet.monkey_patch(os=False)  # noqa
+
+import os
+
+from oslo_config import cfg
+from oslo_log import log as logging
+from oslo_service import threadgroup
+from paste import deploy
+
+from designate import conf
+from designate import policy
+from designate import rpc
+from designate import service
+from designate.common import config
+
+CONF = conf.CONF
+
+CONFIG_FILES = ['api-paste.ini', 'designate.conf']
+
+
+def _get_config_files(env=None):
+    if env is None:
+        env = os.environ
+    dirname = env.get('OS_DESIGNATE_CONFIG_DIR', '/etc/designate').strip()
+    return [os.path.join(dirname, config_file) for config_file in CONFIG_FILES]
+
+
+def init_application():
+    conf_files = _get_config_files()
+    logging.register_options(cfg.CONF)
+    cfg.CONF([], project='designate', default_config_files=conf_files)
+    config.set_defaults()
+    logging.setup(cfg.CONF, 'designate')
+
+    policy.init()
+
+    if not rpc.initialized():
+        rpc.init(CONF)
+
+    heartbeat = service.Heartbeat('api', threadgroup.ThreadGroup())
+    heartbeat.start()
+
+    conf = conf_files[0]
+
+    return deploy.loadapp('config:%s' % conf, name='osapi_dns')

releasenotes/notes/experimental-wsgi-support-8370a8d9b298d5ca.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Added an experimental entrypoint for wsgi called ``designate-api-wsgi``.

setup.cfg

@@ -128,6 +128,9 @@ designate.notification.plugin =
   default = designate.notifications:Default
   audit = designate.notifications:Audit
 
+wsgi_scripts =
+    designate-api-wsgi = designate.api.wsgi:init_application
+
 [egg_info]
 tag_build =
 tag_date = 0