Require an IP when advertising remote unit

Require that a pacemaker remote unit specifies an IP address for
cluster traffic when joining with an existing cluster. This makes
sure the correct netowrk is used in a network space aware
deployment.

Change-Id: I92b3f2644c7bee4e55463ffaae2769c33458dd16
Closes-Bug: #1824514

.gitreview

@@ -0,0 +1,4 @@
+[gerrit]
+host=review.openstack.org
+port=29418
+project=openstack/charm-interface-pacemaker-remote

.zuul.yaml

@@ -0,0 +1,4 @@
+- project:
+    templates:
+      - python35-charm-jobs
+      - openstack-cover-jobs

provides.py

@@ -4,14 +4,27 @@ from charms.reactive import Endpoint
 
 class PacemakerRemoteProvides(Endpoint):
 
-    def publish_info(self, remote_hostname, stonith_hostname=None,
+    def publish_info(self, remote_hostname, remote_ip, stonith_hostname=None,
                      enable_resources=True):
-        """
-        Publish the stonith info
+        """Publish the stonith info.
+
+
+       :param remote_hostname: The hostname of this unit
+       :type remote_hostname: str
+       :param remote_ip: The IP address that the c;uster should contanct this
+                         node on.
+       :type remote_ip: str
+       :param stonith_hostname: The name used by the stonith device to refer
+                                to this node.
+       :type stonith_hostname: str
+       :param enable_resources: Whether this node should run resources from
+                                the cluster.
+       :type enable_resources: bool
         """
         for relation in self.relations:
             relation.to_publish['stonith-hostname'] = stonith_hostname
             relation.to_publish['remote-hostname'] = remote_hostname
+            relation.to_publish['remote-ip'] = remote_ip
             relation.to_publish['enable-resources'] = enable_resources
 
     def get_pacemaker_key(self):

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 skipsdist = True
-envlist = pep8,py3
+envlist = pep8,py35
 skip_missing_interpreters = True
 
 [testenv]
@@ -10,8 +10,8 @@ setenv = VIRTUAL_ENV={envdir}
 install_command =
   pip install {opts} {packages}
 
-[testenv:py3]
-basepython = python3
+[testenv:py35]
+basepython = python3.5
 deps = -r{toxinidir}/test-requirements.txt
 commands = stestr run {posargs}
 
@@ -20,6 +20,33 @@ basepython = python3
 deps = -r{toxinidir}/test-requirements.txt
 commands = flake8 {posargs} .
 
+[testenv:cover]
+# Technique based heavily upon
+# https://github.com/openstack/nova/blob/master/tox.ini
+basepython = python3
+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
+
+[coverage:run]
+branch = True
+concurrency = multiprocessing
+parallel = True
+source =
+    .
+omit =
+    .tox/*
+    */charmhelpers/*
+    unit_tests/*
+
 [testenv:venv]
 commands = {posargs}
 

unit_tests/test_provides.py

@@ -101,10 +101,12 @@ class TestPacemakerRemoteProvides(unittest.TestCase):
         self.relation_obj._relations = [mock_rel]
         self.relation_obj.publish_info(
             'node1.az1.local',
+            '10.0.0.10',
             stonith_hostname='node1.stonith',
             enable_resources=True)
         expect = {
             'remote-hostname': 'node1.az1.local',
+            'remote-ip': '10.0.0.10',
             'stonith-hostname': 'node1.stonith',
             'enable-resources': True}
         self.assertEqual(