From d658c0974c8600b260e18d0f05672c4fac751e53 Mon Sep 17 00:00:00 2001
From: Liam Young <liam.young@canonical.com>
Date: Fri, 11 Jan 2019 12:42:34 +0000
Subject: [PATCH] Charm class and handlers for Cinder plugin

Add a charm class to base Cinder plugins from and associated
default handlers.

Depends-On: Icad5f72939b1e33d15adf2638f8e344235a9318b
Change-Id: Ieb5f274c54c693c7c1f5ebbc57bcfe218827ffeb
---
 charms_openstack/charm/__init__.py            |  2 +
 charms_openstack/charm/classes.py             | 51 +++++++++++++++++++
 charms_openstack/charm/defaults.py            | 11 ++++
 .../charms_openstack/charm/test_classes.py    | 30 +++++++++++
 4 files changed, 94 insertions(+)

diff --git a/charms_openstack/charm/__init__.py b/charms_openstack/charm/__init__.py
index 8b802d5..23c633d 100644
--- a/charms_openstack/charm/__init__.py
+++ b/charms_openstack/charm/__init__.py
@@ -24,12 +24,14 @@ from charms_openstack.charm.core import (
     register_os_release_selector,
 )
 from charms_openstack.charm.classes import (
+    CinderStoragePluginCharm,
     OpenStackCharm,
     OpenStackAPICharm,
     HAOpenStackCharm,
 )
 
 __all__ = (
+    "CinderStoragePluginCharm",
     "OpenStackCharm",
     "OpenStackAPICharm",
     "HAOpenStackCharm",
diff --git a/charms_openstack/charm/classes.py b/charms_openstack/charm/classes.py
index 8d9e74f..79e5c55 100644
--- a/charms_openstack/charm/classes.py
+++ b/charms_openstack/charm/classes.py
@@ -1,5 +1,6 @@
 import base64
 import contextlib
+import json
 import os
 import random
 import re
@@ -843,3 +844,53 @@ class HAOpenStackCharm(OpenStackAPICharm):
                     cluster.set_address(
                         os_ip.ADDRESS_MAP[addr_type]['binding'],
                         laddr)
+
+
+class CinderStoragePluginCharm(OpenStackCharm):
+
+    abstract_class = True
+
+    # The name of the charm (for printing, etc.)
+    name = ''
+
+    # List of packages to install
+    # XXX execd_preinstall
+    packages = []
+
+    version_package = ''
+    # The list of required services that are checked for assess_status
+    # e.g. required_relations = ['identity-service', 'shared-db']
+    required_relations = []
+
+    # A dictionary of:
+    # {
+    #    'config.file': ['list', 'of', 'services', 'to', 'restart'],
+    #    'config2.file': ['more', 'services'],
+    # }
+    # The files that for the keys of the dict are monitored and if the file
+    # changes the corresponding services are restarted
+    # XXX This is more involved in the tradioional charm so we're
+    # probably missing something herw!
+    restart_map = {}
+
+    # first_release = this is the first release in which this charm works
+    release = ''
+
+    @property
+    def stateless(self):
+        raise NotImplementedError()
+
+    @property
+    def service_name(self):
+        return hookenv.service_name()
+
+    def cinder_configuration(self):
+        raise NotImplementedError()
+
+    def send_storage_backend_data(self):
+        cbend = relations.endpoint_from_flag('storage-backend.connected')
+        cbend.send_plugin_configuration(
+            backend_name=self.service_name,
+            subordinate_configuration=json.dumps(
+                self.cinder_configuration()),
+            stateless=self.stateless)
diff --git a/charms_openstack/charm/defaults.py b/charms_openstack/charm/defaults.py
index da8e640..1954ffb 100644
--- a/charms_openstack/charm/defaults.py
+++ b/charms_openstack/charm/defaults.py
@@ -21,6 +21,7 @@ ALLOWED_DEFAULT_HANDLERS = [
     'update-status',
     'upgrade-charm',
     'certificates.available',
+    'storage-backend.connected',
 ]
 
 # Where to store the default handler functions for each default state
@@ -146,6 +147,16 @@ def make_default_certificates_available_handler():
     reactive.set_state('charms.openstack.do-default-certificates.available')
 
 
+@_map_default_handler('storage-backend.connected')
+def make_default_storage_backend_connected_handler():
+    """Set the default storage-backend.connected state so that the default
+    handler in layer-openstack can run.
+    Convoluted, because charms.reactive will only run handlers in the reactive
+    or hooks directory.
+    """
+    reactive.set_state('charms.openstack.do-default-storage-backend.connected')
+
+
 @_map_default_handler('shared-db.connected')
 def make_default_setup_database_handler():
     """Set the default shared-db.connected state so that the default handler in
diff --git a/unit_tests/charms_openstack/charm/test_classes.py b/unit_tests/charms_openstack/charm/test_classes.py
index 7c028ac..9de8e22 100644
--- a/unit_tests/charms_openstack/charm/test_classes.py
+++ b/unit_tests/charms_openstack/charm/test_classes.py
@@ -1020,3 +1020,33 @@ class TestHAOpenStackCharm(BaseOpenStackCharmTest):
         with self.target.update_central_cacerts(['file1']):
             pass
         self.assertFalse(self.run_update_certs.called)
+
+
+class TestCinderStoragePluginCharm(BaseOpenStackCharmTest):
+
+    def setUp(self):
+        super(TestCinderStoragePluginCharm, self).setUp(
+            chm.CinderStoragePluginCharm,
+            TEST_CONFIG)
+
+    def test_stateless(self):
+        with self.assertRaises(NotImplementedError):
+            self.target.stateless
+
+    def test_service_name(self):
+        self.patch_object(chm.hookenv, 'service_name', return_value='svc1')
+        self.assertEqual(self.target.service_name, 'svc1')
+
+    def test_cinder_configuration(self):
+        with self.assertRaises(NotImplementedError):
+            self.target.cinder_configuration()
+
+    def test_send_storage_backend_data(self):
+        self.patch_object(chm.hookenv, 'service_name', return_value='svc1')
+        ep_mock = mock.MagicMock()
+        self.patch_object(
+            chm.relations,
+            'endpoint_from_flag',
+            return_value=ep_mock)
+        with self.assertRaises(NotImplementedError):
+            self.target.send_storage_backend_data()