Handle situation when a configdrive is already mounted

Glean mounts the configdrive and does not unmount it afterwards.
If a mount point already exists, just use it.

Change-Id: Ia62279afbb9fd9770864942dc40629b69ae8f4ae

ironic_python_agent/tests/unit/test_utils.py

@@ -1028,21 +1028,35 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
         mock_copy.assert_not_called()
 
     def test_no_files(self, mock_execute, mock_copy, mock_find_device):
+        mock_execute.side_effect = [
+            processutils.ProcessExecutionError,
+            ('', ''),
+            ('', ''),
+        ]
         mock_find_device.return_value = '/dev/something'
         utils.copy_config_from_vmedia()
         mock_execute.assert_has_calls([
+            mock.call('findmnt', '-n', '-oTARGET', '/dev/something'),
             mock.call('mount', '/dev/something', mock.ANY),
             mock.call('umount', mock.ANY),
         ])
         mock_copy.assert_not_called()
 
+    def test_mounted_no_files(self, mock_execute, mock_copy, mock_find_device):
+        mock_execute.return_value = '/some/path', ''
+        mock_find_device.return_value = '/dev/something'
+        utils.copy_config_from_vmedia()
+        mock_execute.assert_called_once_with(
+            'findmnt', '-n', '-oTARGET', '/dev/something')
+        mock_copy.assert_not_called()
+
     @mock.patch.object(os, 'makedirs', autospec=True)
     def test_copy(self, mock_makedirs, mock_execute, mock_copy,
                   mock_find_device):
         mock_find_device.return_value = '/dev/something'
         path = None
 
-        def _fake_exec(command, arg1, arg2=None):
+        def _fake_exec(command, arg1, arg2=None, *args):
             nonlocal path
             if command == 'mount':
                 path = arg2
@@ -1059,6 +1073,8 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
                 with open(os.path.join(path, 'etc', 'ironic-python-agent.d',
                                        'ironic.conf'), 'wt') as fp:
                     fp.write('I am a config')
+            elif command == 'findmnt':
+                raise processutils.ProcessExecutionError("")
             else:
                 self.assertEqual('umount', command)
 
@@ -1080,3 +1096,39 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
             mock.call(mock.ANY, '/etc/ironic-python-agent.d/ironic.conf'),
         ], any_order=True)
         self.assertFalse(os.path.exists(path))
+
+    @mock.patch.object(os, 'makedirs', autospec=True)
+    def test_copy_mounted(self, mock_makedirs, mock_execute, mock_copy,
+                          mock_find_device):
+        mock_find_device.return_value = '/dev/something'
+        path = tempfile.mkdtemp()
+        self.addCleanup(lambda: shutil.rmtree(path))
+
+        # NOTE(dtantsur): makedirs is mocked
+        os.mkdir(os.path.join(path, 'etc'))
+        os.mkdir(os.path.join(path, 'etc', 'ironic-python-agent'))
+        os.mkdir(os.path.join(path, 'etc', 'ironic-python-agent.d'))
+        with open(os.path.join(path, 'not copied'), 'wt') as fp:
+            fp.write('not copied')
+        with open(os.path.join(path, 'etc', 'ironic-python-agent',
+                               'ironic.crt'), 'wt') as fp:
+            fp.write('I am a cert')
+        with open(os.path.join(path, 'etc', 'ironic-python-agent.d',
+                               'ironic.conf'), 'wt') as fp:
+            fp.write('I am a config')
+
+        mock_execute.return_value = path, ''
+        mock_find_device.return_value = '/dev/something'
+
+        utils.copy_config_from_vmedia()
+
+        mock_makedirs.assert_has_calls([
+            mock.call('/etc/ironic-python-agent', exist_ok=True),
+            mock.call('/etc/ironic-python-agent.d', exist_ok=True),
+        ], any_order=True)
+        mock_execute.assert_called_once_with(
+            'findmnt', '-n', '-oTARGET', '/dev/something')
+        mock_copy.assert_has_calls([
+            mock.call(mock.ANY, '/etc/ironic-python-agent/ironic.crt'),
+            mock.call(mock.ANY, '/etc/ironic-python-agent.d/ironic.conf'),
+        ], any_order=True)

ironic_python_agent/utils.py

@@ -212,21 +212,9 @@ def _early_log(msg, *args):
     print('ironic-python-agent:', msg % args, file=sys.stderr)
 
 
-def copy_config_from_vmedia():
-    """Copies any configuration from a virtual media device.
-
-    Copies files under /etc/ironic-python-agent and /etc/ironic-python-agent.d.
-    """
-    vmedia_device_file = _find_device_by_labels(
-        ['config-2', 'vmedia_boot_iso'])
-    if not vmedia_device_file:
-        _early_log('No virtual media device detected')
-        return
-
-    with _mounted(vmedia_device_file) as vmedia_mount_point:
+def _copy_config_from(path):
     for ext in ('', '.d'):
-            src = os.path.join(vmedia_mount_point, 'etc',
-                               'ironic-python-agent%s' % ext)
+        src = os.path.join(path, 'etc', 'ironic-python-agent%s' % ext)
         if not os.path.isdir(src):
             _early_log('%s not found', src)
             continue
@@ -248,6 +236,34 @@ def copy_config_from_vmedia():
             raise errors.VirtualMediaBootError(msg)
 
 
+def _find_mount_point(device):
+    try:
+        path, _e = execute('findmnt', '-n', '-oTARGET', device)
+    except processutils.ProcessExecutionError:
+        return
+    else:
+        return path.strip()
+
+
+def copy_config_from_vmedia():
+    """Copies any configuration from a virtual media device.
+
+    Copies files under /etc/ironic-python-agent and /etc/ironic-python-agent.d.
+    """
+    vmedia_device_file = _find_device_by_labels(
+        ['config-2', 'vmedia_boot_iso'])
+    if not vmedia_device_file:
+        _early_log('No virtual media device detected')
+        return
+
+    mounted = _find_mount_point(vmedia_device_file)
+    if mounted:
+        _copy_config_from(mounted)
+    else:
+        with _mounted(vmedia_device_file) as vmedia_mount_point:
+            _copy_config_from(vmedia_mount_point)
+
+
 def _get_cached_params():
     """Helper method to get cached params to ease unit testing."""
     return AGENT_PARAMS_CACHED