Add versioning support

Implements blueprint murano-api-version-support
Change-Id: Ib24a737c2817f503b4200117886102c4daab311a

etc/murano/murano-api-paste.ini

@@ -1,8 +1,5 @@
 [pipeline:muranoapi]
-pipeline = authtoken context apiv1app
+pipeline = versionnegotiation authtoken context rootapp
-
-[app:apiv1app]
-paste.app_factory = muranoapi.api.v1.router:API.factory
 
 [filter:context]
 paste.filter_factory = muranoapi.api.middleware.context:ContextMiddleware.factory
@@ -11,3 +8,17 @@ paste.filter_factory = muranoapi.api.middleware.context:ContextMiddleware.factor
 #http://docs.openstack.org/developer/keystone/configuringservices.html
 [filter:authtoken]
 paste.filter_factory = keystoneclient.middleware.auth_token:filter_factory
+
+[composite:rootapp]
+use = egg:Paste#urlmap
+/: apiversions
+/v1: apiv1app
+
+[app:apiversions]
+paste.app_factory = muranoapi.api.versions:create_resource
+
+[app:apiv1app]
+paste.app_factory = muranoapi.api.v1.router:API.factory
+
+[filter:versionnegotiation]
+paste.filter_factory = muranoapi.api.middleware.version_negotiation:VersionNegotiationFilter.factory

muranoapi/api/middleware/version_negotiation.py

@@ -0,0 +1,96 @@
+#    Copyright (c) 2014 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.
+
+"""
+A filter middleware that inspects the requested URI for a version string
+and/or Accept headers and attempts to negotiate an API controller to
+return
+"""
+
+from oslo.config import cfg
+
+from muranoapi.api import versions
+from muranoapi.openstack.common.gettextutils import _  # noqa
+import muranoapi.openstack.common.log as logging
+from muranoapi.openstack.common import wsgi
+
+CONF = cfg.CONF
+LOG = logging.getLogger(__name__)
+
+
+class VersionNegotiationFilter(wsgi.Middleware):
+    @classmethod
+    def factory(cls, global_conf, **local_conf):
+        def filter(app):
+            return cls(app)
+        return filter
+
+    def __init__(self, app):
+        self.versions_app = versions.Controller()
+        super(VersionNegotiationFilter, self).__init__(app)
+
+    def process_request(self, req):
+        """Try to find a version first in the accept header, then the URL"""
+        msg = _("Determining version of request: %(method)s %(path)s"
+                " Accept: %(accept)s")
+        args = {'method': req.method, 'path': req.path, 'accept': req.accept}
+        LOG.debug(msg % args)
+
+        LOG.debug(_("Using url versioning"))
+        # Remove version in url so it doesn't conflict later
+        req_version = self._pop_path_info(req)
+
+        try:
+            version = self._match_version_string(req_version)
+        except ValueError:
+            LOG.debug(_("Unknown version. Returning version choices."))
+            return self.versions_app
+
+        req.environ['api.version'] = version
+        req.path_info = ''.join(('/v', str(version), req.path_info))
+        LOG.debug(_("Matched version: v%d"), version)
+        LOG.debug('new path %s' % req.path_info)
+        return None
+
+    def _match_version_string(self, subject):
+        """
+        Given a string, tries to match a major and/or
+        minor version number.
+
+        :param subject: The string to check
+        :returns version found in the subject
+        :raises ValueError if no acceptable version could be found
+        """
+        if subject in ('v1',):
+            major_version = 1
+        else:
+            raise ValueError()
+        return major_version
+
+    def _pop_path_info(self, req):
+        """
+        'Pops' off the next segment of PATH_INFO, returns the popped
+        segment. Do NOT push it onto SCRIPT_NAME.
+        """
+        path = req.path_info
+        if not path:
+            return None
+        while path.startswith('/'):
+            path = path[1:]
+        idx = path.find('/')
+        if idx == -1:
+            idx = len(path)
+        r = path[:idx]
+        req.path_info = path[idx:]
+        return r

muranoapi/api/v1/deployments.py

@@ -19,7 +19,6 @@ from muranoapi.common import utils
 from muranoapi.db import models
 from muranoapi.db import session as db_session
 
-
 from muranoapi.openstack.common.gettextutils import _  # noqa
 from muranoapi.openstack.common import log as logging
 from muranoapi.openstack.common import wsgi

muranoapi/api/v1/environments.py

@@ -15,7 +15,6 @@
 from sqlalchemy import desc
 from webob import exc
 
-
 from muranoapi.api.v1 import statistics
 from muranoapi.common import utils
 from muranoapi.db import models
@@ -23,7 +22,6 @@ from muranoapi.db.services import core_services
 from muranoapi.db.services import environments as envs
 from muranoapi.db import session as db_session
 
-
 from muranoapi.openstack.common.gettextutils import _  # noqa
 from muranoapi.openstack.common import log as logging
 from muranoapi.openstack.common import wsgi

muranoapi/api/v1/router.py

@@ -11,7 +11,6 @@
 #    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 routes
 
 from muranoapi.api.v1 import deployments

muranoapi/api/versions.py

@@ -0,0 +1,62 @@
+#    Copyright (c) 2014 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 httplib
+
+from oslo.config import cfg
+import webob.dec
+
+from muranoapi.openstack.common import jsonutils
+from muranoapi.openstack.common import wsgi
+
+
+CONF = cfg.CONF
+
+
+class Controller(object):
+
+    """A wsgi controller that reports which API versions are supported."""
+
+    def index(self, req):
+        """Respond to a request for all OpenStack API versions."""
+        def build_version_object(version, path, status):
+            return {
+                'id': 'v%s' % version,
+                'status': status,
+                'links': [
+                    {
+                        'rel': 'self',
+                        'href': '%s/%s/' % (req.host_url, path),
+                    },
+                ],
+            }
+
+        version_objs = []
+        version_objs.extend([
+            build_version_object(1.0, 'v1', 'CURRENT'),
+        ])
+
+        response = webob.Response(request=req,
+                                  status=httplib.MULTIPLE_CHOICES,
+                                  content_type='application/json')
+        response.body = jsonutils.dumps(dict(versions=version_objs))
+        return response
+
+    @webob.dec.wsgify(RequestClass=wsgi.Request)
+    def __call__(self, req):
+        return self.index(req)
+
+
+def create_resource(conf):
+    return wsgi.Resource(Controller())