From ba7e3ac9e47314de9593f16e62445f271627add8 Mon Sep 17 00:00:00 2001
From: Alex Kavanagh <alex.kavanagh@canonical.com>
Date: Wed, 2 Jun 2021 10:18:59 +0100
Subject: [PATCH] Fix charm so that on focal it uses named service

Pre-focal the service was called 'bind9'.  On focal+ it is called
'named'.  This patch introduces a number of changes to make this
possible:

 * Modify existing charm class "DesignateBindCharm" to include a check
   to see if the distro version is "focal" or higher; if so switch
   the service name to 'named'.

Change-Id: Ida65c620fa81715d37e468217aea28f160cf31ee
Closes-Bug: #1929770
---
 src/lib/charm/openstack/designate_bind.py     | 20 +++++++++++
 ...test_lib_charm_openstack_designate_bind.py | 34 +++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/src/lib/charm/openstack/designate_bind.py b/src/lib/charm/openstack/designate_bind.py
index febc030..718b2f4 100644
--- a/src/lib/charm/openstack/designate_bind.py
+++ b/src/lib/charm/openstack/designate_bind.py
@@ -236,8 +236,28 @@ class DesignateBindCharm(openstack_charm.OpenStackCharm):
     group = 'bind'
 
     def __init__(self, release=None, **kwargs):
+        self._ensure_override_service_name()
         super(DesignateBindCharm, self).__init__(release='icehouse', **kwargs)
 
+    @classmethod
+    def _ensure_override_service_name(cls):
+        """Override the bind9 service to named for focal+
+
+        This class is instantiated for all versions of Ubuntu, but we also need
+        to check for the host being focal to override the named service to
+        'named'.
+        """
+        release = host.CompareHostReleases(
+            host.lsb_release()['DISTRIB_CODENAME'])
+        if release >= 'focal':
+            cls.services = ['named']
+            cls.restart_map = {
+                '/etc/bind/named.conf.options': cls.services,
+                '/etc/bind/named.conf': cls.services,
+                '/etc/bind/rndc.key': cls.services,
+            }
+            cls.default_service = 'named'
+
     @staticmethod
     def get_rndc_algorithm():
         """Algorithm used to encode rndc secret
diff --git a/unit_tests/test_lib_charm_openstack_designate_bind.py b/unit_tests/test_lib_charm_openstack_designate_bind.py
index 643d61d..d9d736e 100644
--- a/unit_tests/test_lib_charm_openstack_designate_bind.py
+++ b/unit_tests/test_lib_charm_openstack_designate_bind.py
@@ -33,6 +33,13 @@ class Helper(test_utils.PatchHelper):
         super().setUp()
         self.patch('charmhelpers.core.hookenv.config', name='ch_config')
         self.ch_config.side_effect = lambda: {'ssl_param': None}
+        self.patch_object(designate_bind, "host", name="ch_core_host")
+        self.ch_core_host.lsb_release.return_value = {
+            "DISTRIB_CODENAME": "bionic"
+        }
+        # simply the CompareHostReleases to just return then string for
+        # comparisons. (won't work for xenial/bionic)
+        self.ch_core_host.CompareHostReleases.side_effect = lambda x: x
         self.patch('charms_openstack.charm.core._singleton', new=None)
 
 
@@ -44,6 +51,33 @@ class TestOpenStackDesignateBind(Helper):
         designate_bind.install()
         self.install.assert_called_once_with()
 
+    def test_service_is_bind9_pre_focal(self):
+        charm = designate_bind.DesignateBindCharm.singleton
+        self.assertEqual(charm.services, ["bind9"])
+        for v in charm.restart_map.values():
+            self.assertEqual(v, ["bind9"])
+        self.assertEqual(charm.default_service, "bind9")
+
+    def test_service_is_bind9_when_bionic(self):
+        self.ch_core_host.lsb_release.return_value = {
+            "DISTRIB_CODENAME": "bionic"
+        }
+        charm = designate_bind.DesignateBindCharm.singleton
+        self.assertEqual(charm.services, ["bind9"])
+        for v in charm.restart_map.values():
+            self.assertEqual(v, ["bind9"])
+        self.assertEqual(charm.default_service, "bind9")
+
+    def test_service_is_named_focal_plus(self):
+        self.ch_core_host.lsb_release.return_value = {
+            "DISTRIB_CODENAME": "focal"
+        }
+        charm = designate_bind.DesignateBindCharm.singleton
+        self.assertEqual(charm.services, ["named"])
+        for v in charm.restart_map.values():
+            self.assertEqual(v, ["named"])
+        self.assertEqual(charm.default_service, "named")
+
     def test_init_rndckey(self):
         self.patch_object(
             designate_bind.DesignateBindCharm.singleton, 'init_rndckey')