Add low level api

* api.api.BaseAPI holds the common operations
* api.compute.APIv2, api.identity_v2, api.identity_v3 and  api.object_store.APIv1
  represent the versioned REST API interfaces

* Changes to OSC include adding the API object to the existing client objects,
  although in time these could replace the client objects.

* The existing Object-Store commands in OSC have been moved to openstackclient.api
* A couple of Compute commands have been added to demonstrate the CRUD operations
* An Identity command was implemented for both v2 and v3 to work out versioning

* Tests for the API-layer are included

Change-Id: If0bf70adc18ceb5782237fc7f4f8d8cf1936a4c7

openstackclient/api/api.py

@@ -0,0 +1,236 @@
+#   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.
+#
+
+"""Base API Library"""
+
+import simplejson as json
+
+from keystoneclient.openstack.common.apiclient \
+    import exceptions as ksc_exceptions
+
+
+class BaseAPI(object):
+    """Base API"""
+
+    def __init__(
+        self,
+        session=None,
+        service_type=None,
+        endpoint=None,
+        **kwargs
+    ):
+        """Base object that contains some common API objects and methods
+
+        :param Session session:
+            The default session to be used for making the HTTP API calls.
+        :param string service_type:
+            API name, i.e. ``identity`` or ``compute``
+        :param string endpoint:
+            The URL from the Service Catalog to be used as the base for API
+            requests on this API.
+        """
+
+        super(BaseAPI, self).__init__()
+
+        # a requests.Session-style interface
+        self.session = session
+        self.service_type = service_type
+        self.endpoint = endpoint
+
+        if self.endpoint is None:
+            # TODO(dtroyer): look it up via session
+            pass
+
+    def _request(self, method, url, session=None, **kwargs):
+        """Perform call into session
+
+        All API calls are funneled through this method to provide a common
+        place to finalize the passed URL and other things.
+
+        :param string method:
+            The HTTP method name, i.e. ``GET``, ``PUT``, etc
+        :param string url:
+            The API-specific portion of the URL path
+        :param Session session:
+            HTTP client session
+        :param kwargs:
+            keyword arguments passed to requests.request().
+        :return: the requests.Response object
+        """
+
+        if not session:
+            session = self.session
+        if not session:
+            # TODO(dtroyer): sort this
+            raise Exception
+
+        if self.endpoint:
+            url = '/'.join([self.endpoint.rstrip('/'), url.lstrip('/')])
+
+        # Why is ksc session backwards???
+        ret = session.request(url, method, **kwargs)
+        # print("%s %s return: %s\n%s" % (method, url, ret.status_code, ret._content))
+        return ret
+
+    # The basic action methods all take a Session and return dict/lists
+
+    def create(
+        self,
+        url,
+        session=None,
+        **params
+    ):
+        """Create a new resource
+
+        :param string url:
+            The API-specific portion of the URL path
+        :param Session session:
+            HTTP client session
+        """
+
+        ret = self._request('PUT', url, session=session, **params)
+        # Should this move into _requests()?
+        try:
+            return ret.json()
+        except json.JSONDecodeError:
+            pass
+        return ret
+
+    def delete(
+        self,
+        url,
+        session=None,
+        **params
+    ):
+        """Delete a resource
+
+        :param string url:
+            The API-specific portion of the URL path
+        :param Session session:
+            HTTP client session
+        """
+
+        return self._request('DELETE', url, **params)
+
+    def list(
+        self,
+        url,
+        session=None,
+        body=None,
+        **params
+    ):
+        """Return a list of resources
+
+        :param string url:
+            The API-specific portion of the URL path
+        :param Session session:
+            HTTP client session
+        :param body: data that will be encoded as JSON and passed in POST
+            request (GET will be sent by default)
+        """
+
+        if body:
+            return self._request(
+                'POST',
+                url,
+                # service=self.service_type,
+                json=body,
+                params=params,
+            ).json()
+        else:
+            return self._request(
+                'GET',
+                url,
+                # service=self.service_type,
+                params=params,
+            ).json()
+
+    # Layered actions built on top of the basic action methods do not
+    # explicitly take a Session but may still be passed on kwargs
+
+    def find_bulk(
+        self,
+        url,
+        **kwargs
+    ):
+        """Bulk load and filter locally
+
+        :param string url:
+            The API-specific portion of the URL path
+        :param kwargs: dict of AVPs to match - logical AND
+        :returns: list of resource dicts
+        """
+
+        items = self.list(url)
+        if type(items) == dict:
+            # strip off the enclosing dict
+            key = list(items.keys())[0]
+            items = items[key]
+
+        ret = []
+        for o in items:
+            try:
+                if all(o[attr] == kwargs[attr] for attr in kwargs.keys()):
+                    ret.append(o)
+            except KeyError:
+                continue
+
+        return ret
+
+    def find_one(
+        self,
+        url,
+        **kwargs
+    ):
+        """Find a resource by name or ID
+
+        :param string url:
+            The API-specific portion of the URL path
+        :returns: list of resource dicts
+        """
+
+        bulk_list = self.find_bulk(url, **kwargs)
+        num_bulk = len(bulk_list)
+        if num_bulk == 0:
+            msg = "none found"
+            raise ksc_exceptions.NotFound(msg)
+        elif num_bulk > 1:
+            msg = "many found"
+            raise RuntimeError(msg)
+        return bulk_list[0]
+
+    def find(
+        self,
+        url,
+        attr=None,
+        search=None,
+    ):
+        """Find a single resource by name or ID
+
+        :param string url:
+            The API-specific portion of the URL path
+        :param attr: name of attribute for secondary search
+        :param search: search expression
+        """
+
+        try:
+            ret = self._request('GET', "/%s/%s" % (url, search)).json()
+        except ksc_exceptions.NotFound:
+            kwargs = {attr: search}
+            try:
+                ret = self.find_one("/%s/detail" % (url), **kwargs)
+            except ksc_exceptions.NotFound:
+                msg = "%s not found" % search
+                raise ksc_exceptions.NotFound(msg)
+
+        return ret

openstackclient/api/compute.py

@@ -0,0 +1,67 @@
+#   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.
+#
+
+"""Compute v2 API Library"""
+
+from openstackclient.api import api
+
+
+class APIv2(api.BaseAPI):
+    """Compute v2 API"""
+
+    def __init__(self, **kwargs):
+        super(APIv2, self).__init__(**kwargs)
+
+    def flavor_list(
+        self,
+        detailed=True,
+        is_public=True,
+    ):
+        """Get available flavors
+
+        :param detailed: retrieve detailed response from server if True
+        :param is_public: return only public flavors if True
+        """
+
+        params = {}
+
+        if not is_public:
+            params['is_public'] = is_public
+
+        url = "/flavors"
+        if detailed:
+            url += "/detail"
+
+        return self.list(url, **params)['flavors']
+
+    def flavor_show(
+        self,
+        flavor=None,
+    ):
+
+        return self.find("flavors", 'name', flavor)
+
+    def key_list(
+        self,
+    ):
+        """Get available keys
+
+        This is an extension, look at loading it separately
+        """
+
+        # Each effin object has the 'keypair' wrapper...
+        ret = []
+        for k in self.list('os-keypairs')['keypairs']:
+            ret.append(k['keypair'])
+
+        return ret

openstackclient/api/identity_v2.py

@@ -0,0 +1,33 @@
+#   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.
+#
+
+"""Identity v2 API Library"""
+
+from openstackclient.api import api
+
+
+class APIv2(api.BaseAPI):
+    """Identity v2 API"""
+
+    def __init__(self, **kwargs):
+        super(APIv2, self).__init__(**kwargs)
+
+    def project_list(
+        self,
+    ):
+        """Get available projects
+
+        can add limit/marker
+        """
+
+        return self.list('tenants')['tenants']

openstackclient/api/identity_v3.py

@@ -0,0 +1,39 @@
+#   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.
+#
+
+"""Identity v3 API Library"""
+
+from openstackclient.api import api
+
+
+class APIv3(api.BaseAPI):
+    """Identity v3 API"""
+
+    def __init__(self, **kwargs):
+        super(APIv3, self).__init__(**kwargs)
+
+    def find_domain(self, domain):
+        """Find domain by name or id"""
+        return self.find('domain', attr='name', search=domain)['domain']
+
+    def project_list(
+        self,
+        **params
+    ):
+        """Get available projects
+
+        can add limit/marker
+        need to convert to v3...
+        """
+
+        return self.list('projects')['projects']