Merge ~hloeung/ubuntu-repository-cache:master into ubuntu-repository-cache:master

[Haw Loeung]

Fix mtr metrics to use IPv4 when squid_dns_v4_first to match

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Colin Misare (cmisare)]

LGTM

review: Approve

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision 830c883d1749b953ab7993332a2ac5e28951c0bb

diff --git a/lib/ubuntu_repository_cache/metadata_sync.py b/lib/ubuntu_repository_cache/metadata_sync.py
index b2da773..79acaf9 100644
--- a/lib/ubuntu_repository_cache/metadata_sync.py
+++ b/lib/ubuntu_repository_cache/metadata_sync.py
@@ -155,9 +155,9 @@ def mirror_archive(hostname, apache_root, local_unit, log, mirror_series, rsync_
     max_retries = 5
     for attempt in range(1, max_retries):
         try:
-             # The archive may have multiple IP addresses, try each several times.
-             archive_ips = [i for i in socket.gethostbyname_ex(hostname)[-1]]
-             archive_ip_iterator = cycle(archive_ips)
+            # The archive may have multiple IP addresses, try each several times.
+            archive_ips = [i for i in socket.gethostbyname_ex(hostname)[-1]]
+            archive_ip_iterator = cycle(archive_ips)
         except socket.gaierror as e:
             # Save the exact exception and reuse when we need to
             # reraise it after exhausting all available attempts.
diff --git a/reactive/ubuntu_repository_cache.py b/reactive/ubuntu_repository_cache.py
index d8b8221..5fedca0 100755
--- a/reactive/ubuntu_repository_cache.py
+++ b/reactive/ubuntu_repository_cache.py
@@ -324,7 +324,11 @@ def leader_settings_changed():
     update_website_relation_data()
 
 
[e-mail]_any('config.changed.sync-host', 'config.changed.enable_sync-host_monitoring')
[e-mail]_any(
+    'config.changed.enable_sync-host_monitoring',
+    'config.changed.squid_dns_v4_first',
+    'config.changed.sync-host',
+)
 def update_systemd_mtr_required():
     reactive.set_flag('ubuntu-repository-cache.update-systemd-mtr-required')
 
@@ -341,11 +345,11 @@ def update_systemd_mtr(etc_systemd_path='/etc/systemd/system'):
         status.maintenance('Updating systemd mtr timer & service with sync-host {}'.format(config['sync-host']))
 
         changed = False
-
+        context = {'protocol': '-4 ' if config['squid_dns_v4_first'] else '', 'sync_host': config['sync-host']}
         base = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
         env = jinja2.Environment(loader=jinja2.FileSystemLoader(base), keep_trailing_newline=True)
         template = env.get_template('templates/systemd/mtr-synchost.service')
-        contents = template.render({'sync_host': config['sync-host']})
+        contents = template.render(context)
         changed = _write_file(contents, mtr_service) or changed
         changed = _copy_file('files/systemd/mtr-synchost.timer', mtr_timer) or changed
 
diff --git a/templates/systemd/mtr-synchost.service b/templates/systemd/mtr-synchost.service
index 477024d..538e9ba 100644
--- a/templates/systemd/mtr-synchost.service
+++ b/templates/systemd/mtr-synchost.service
@@ -5,7 +5,7 @@ After=network-online.target
 
 [Service]
 Type=simple
-ExecStart=/usr/bin/mtr -bz -c7 --tcp -P 80 --report-wide {{sync_host}}
+ExecStart=/usr/bin/mtr {{protocol}}-bz -c7 --tcp -P 80 --report-wide {{sync_host}}
 ExecStop=
 User=nobody
 Restart=on-failure
diff --git a/tests/unit/test_ubuntu_repository_cache.py b/tests/unit/test_ubuntu_repository_cache.py
index 17f0c06..14ec2a7 100644
--- a/tests/unit/test_ubuntu_repository_cache.py
+++ b/tests/unit/test_ubuntu_repository_cache.py
@@ -138,6 +138,7 @@ class TestCharm(unittest.TestCase):
     @mock.patch('subprocess.call')
     def test_update_systemd_mtr(self, call, clear_flag):
         self.mock_config.return_value['enable_sync-host_monitoring'] = True
+        self.mock_config.return_value['squid_dns_v4_first'] = False
         ubuntu_repository_cache.update_systemd_mtr(self.tmpdir)
         want = [
             mock.call('ubuntu-repository-cache.active'),
@@ -223,6 +224,31 @@ WantedBy=multi-user.target
         ]
         call.assert_has_calls(want, any_order=True)
 
+    @mock.patch('subprocess.call')
+    def test_update_systemd_mtr_ipv4(self, call):
+        self.mock_config.return_value['enable_sync-host_monitoring'] = True
+        self.mock_config.return_value['squid_dns_v4_first'] = True
+        ubuntu_repository_cache.update_systemd_mtr(self.tmpdir)
+        want = '''[Unit]
+Description=Monitor path to sync host regularly
+Wants=network-online.target
+After=network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/bin/mtr -4 -bz -c7 --tcp -P 80 --report-wide archive.ubuntu.com
+ExecStop=
+User=nobody
+Restart=on-failure
+TimeoutSec=5m
+
+[Install]
+WantedBy=multi-user.target
+'''  # NOQA: E501
+        with open(os.path.join(self.tmpdir, 'mtr-synchost.service'), 'r', encoding='utf-8') as f:
+            got = f.read()
+        self.assertEqual(want, got)
+
     def test__copy_file(self):
         source = os.path.join(self.charm_dir, 'metadata.yaml')
         dest = os.path.join(self.tmpdir, os.path.basename(source))