set_passwords: Add newline to end of sshd config, only restart if updated.

This admittedly does a fairly extensive re-factor to simply add a newline
to the end of sshd_config.

It makes the ssh_config updating portion of set_passwords more testable
and adds tests for that.

The new function is in 'update_ssh_config_lines' which allows you
to update a config with multiple changes even though only a single one
is currently used.

We also only restart the ssh daemon now if a change was made to the
config file.  Before it was always restarted if the user specified
a value for ssh_pwauth other than 'unchanged'.

Thanks to Lorens Kockum for initial diagnosis and patch.

LP: #1677205

1 files changed, 71 insertions, 0 deletions

diff --git a/cloudinit/config/tests/test_set_passwords.py b/cloudinit/config/tests/test_set_passwords.py
new file mode 100644
index 00000000..b051ec82
--- /dev/null
+++ b/cloudinit/config/tests/test_set_passwords.py
@@ -0,0 +1,71 @@
+# This file is part of cloud-init. See LICENSE file for license information.
+
+import mock
+
+from cloudinit.config import cc_set_passwords as setpass
+from cloudinit.tests.helpers import CiTestCase
+from cloudinit import util
+
+MODPATH = "cloudinit.config.cc_set_passwords."
+
+
+class TestHandleSshPwauth(CiTestCase):
+    """Test cc_set_passwords handling of ssh_pwauth in handle_ssh_pwauth."""
+
+    with_logs = True
+
+    @mock.patch(MODPATH + "util.subp")
+    def test_unknown_value_logs_warning(self, m_subp):
+        setpass.handle_ssh_pwauth("floo")
+        self.assertIn("Unrecognized value: ssh_pwauth=floo",
+                      self.logs.getvalue())
+        m_subp.assert_not_called()
+
+    @mock.patch(MODPATH + "update_ssh_config", return_value=True)
+    @mock.patch(MODPATH + "util.subp")
+    def test_systemctl_as_service_cmd(self, m_subp, m_update_ssh_config):
+        """If systemctl in service cmd: systemctl restart name."""
+        setpass.handle_ssh_pwauth(
+            True, service_cmd=["systemctl"], service_name="myssh")
+        self.assertEqual(mock.call(["systemctl", "restart", "myssh"]),
+                         m_subp.call_args)
+
+    @mock.patch(MODPATH + "update_ssh_config", return_value=True)
+    @mock.patch(MODPATH + "util.subp")
+    def test_service_as_service_cmd(self, m_subp, m_update_ssh_config):
+        """If systemctl in service cmd: systemctl restart name."""
+        setpass.handle_ssh_pwauth(
+            True, service_cmd=["service"], service_name="myssh")
+        self.assertEqual(mock.call(["service", "myssh", "restart"]),
+                         m_subp.call_args)
+
+    @mock.patch(MODPATH + "update_ssh_config", return_value=False)
+    @mock.patch(MODPATH + "util.subp")
+    def test_not_restarted_if_not_updated(self, m_subp, m_update_ssh_config):
+        """If config is not updated, then no system restart should be done."""
+        setpass.handle_ssh_pwauth(True)
+        m_subp.assert_not_called()
+        self.assertIn("No need to restart ssh", self.logs.getvalue())
+
+    @mock.patch(MODPATH + "update_ssh_config", return_value=True)
+    @mock.patch(MODPATH + "util.subp")
+    def test_unchanged_does_nothing(self, m_subp, m_update_ssh_config):
+        """If 'unchanged', then no updates to config and no restart."""
+        setpass.handle_ssh_pwauth(
+            "unchanged", service_cmd=["systemctl"], service_name="myssh")
+        m_update_ssh_config.assert_not_called()
+        m_subp.assert_not_called()
+
+    @mock.patch(MODPATH + "util.subp")
+    def test_valid_change_values(self, m_subp):
+        """If value is a valid changen value, then update should be called."""
+        upname = MODPATH + "update_ssh_config"
+        optname = "PasswordAuthentication"
+        for value in util.FALSE_STRINGS + util.TRUE_STRINGS:
+            optval = "yes" if value in util.TRUE_STRINGS else "no"
+            with mock.patch(upname, return_value=False) as m_update:
+                setpass.handle_ssh_pwauth(value)
+                m_update.assert_called_with({optname: optval})
+        m_subp.assert_not_called()
+
+# vi: ts=4 expandtab