Add support for handling of forwarded broker requests

Change-Id: I0d4ed457e1d59eabed3340f5dc7d8353d5d66f04

.zuul.yaml

@@ -1,4 +1,3 @@
 - project:
     templates:
-      - python35-charm-jobs
-      - openstack-python3-ussuri-jobs
+      - openstack-python3-charm-jobs

requires.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import ipaddress
+import json
 import socket
 import uuid
 
@@ -151,6 +152,24 @@ class CephRBDMirrorRequires(Endpoint):
             ch_ceph.send_request_if_needed(current_request,
                                            relation=self.endpoint_name)
 
+    def maybe_send_rq(self, rq):
+        """Send single broker request with all operations if needed.
+
+        The rbd-mirror charm has two endpoints using this interface connected
+        to the ceph-mon in the local and remote clusters. Subsequently each
+        relation typically only has one other participant, the ceph-mon.
+
+        The charm will recieve a verbatim copy of every broker request the
+        ceph-mon knows about in one end and then extract and filter all the
+        operations and collapse into one new single broker request that is
+        maintained with the ceph-mon in the other end.
+
+        :param rq: Broker Request to evaluate for sending.
+        :type rq: ch_ceph.CephBrokerRq
+        """
+        for relation in self.relations:
+            ch_ceph.send_request_if_needed(rq, relation=self.endpoint_name)
+
     @property
     def auth(self):
         """Retrieve ``auth`` from relation data."""
@@ -216,3 +235,12 @@ class CephRBDMirrorRequires(Endpoint):
     @property
     def pools(self):
         return self.all_joined_units.received['pools']
+
+    @property
+    def broker_requests(self):
+        if ('broker_requests' in self.all_joined_units.received and
+                self.all_joined_units.received['broker_requests'] is not None):
+            for json_rq in self.all_joined_units.received['broker_requests']:
+                yield json.loads(json_rq)
+        # Empty return in generator provides empty iterator and not None PEP479
+        return

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 skipsdist = True
-envlist = pep8,py37
+envlist = pep8,py3
 # NOTE(beisner): Avoid build/test env pollution by not enabling sitepackages.
 sitepackages = False
 # NOTE(beisner): Avoid false positives by not skipping missing interpreters.
@@ -69,6 +69,20 @@ commands =
     coverage xml -o cover/coverage.xml
     coverage report
 
+[testenv:py38]
+basepython = python3.8
+deps = -r{toxinidir}/test-requirements.txt
+setenv =
+    {[testenv]setenv}
+    PYTHON=coverage run
+commands =
+    coverage erase
+    stestr run {posargs}
+    coverage combine
+    coverage html -d cover
+    coverage xml -o cover/coverage.xml
+    coverage report
+
 [testenv:pep8]
 basepython = python3
 deps = -r{toxinidir}/test-requirements.txt
@@ -89,4 +103,4 @@ omit =
 
 [flake8]
 # E402 ignore necessary for path append before sys module import in actions
-ignore = E402
+ignore = E402,W504

unit_tests/test_requires.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import json
 import mock
 import requires
 
@@ -209,3 +210,29 @@ class TestCephRBDMirrorRequires(test_utils.PatchHelper):
         self._all_joined_units.received.__getitem__.assert_called_once_with(
             'ceph-cluster-address')
         self.resolve_network_cidr.assert_called_once_with('192.0.2.1')
+
+    def test_maybe_send_rq(self):
+        self.patch_requires_class('_relations')
+        relation = mock.MagicMock()
+        self._relations.__iter__.return_value = [relation]
+        self.patch_object(requires.ch_ceph, 'send_request_if_needed')
+        self.requires_class.maybe_send_rq('aRq')
+        self.send_request_if_needed.assert_called_once_with(
+            'aRq', relation='some-endpoint')
+
+    def test_broker_requests(self):
+        self.patch_requires_class('_all_joined_units')
+        self._all_joined_units.received.__contains__.return_value = True
+        self._all_joined_units.received.__getitem__.return_value = [
+            json.dumps({'fakereq': 0}),
+            json.dumps({'fakereq': 1}),
+        ]
+        for rq in self.requires_class.broker_requests:
+            self.assertIn(rq['fakereq'], (0, 1))
+        self._all_joined_units.received.__contains__.return_value = False
+        with self.assertRaises(StopIteration):
+            next(self.requires_class.broker_requests)
+        self._all_joined_units.received.__contains__.return_value = True
+        self._all_joined_units.received.__getitem__.return_value = None
+        with self.assertRaises(StopIteration):
+            next(self.requires_class.broker_requests)