Merge "Unmount config drives"

ironic_python_agent/tests/unit/test_utils.py

@@ -22,6 +22,7 @@ import shutil
 import subprocess
 import tarfile
 import tempfile
+import time
 from unittest import mock
 
 from ironic_lib import utils as ironic_utils
@@ -877,6 +878,7 @@ class TestClockSyncUtils(ironic_agent_base.IronicAgentTest):
         self.assertEqual(0, mock_execute.call_count)
 
 
+@mock.patch.object(utils, '_unmount_any_config_drives', autospec=True)
 @mock.patch.object(utils, '_booted_from_vmedia', autospec=True)
 @mock.patch.object(utils, '_check_vmedia_device', autospec=True)
 @mock.patch.object(utils, '_find_vmedia_device_by_labels', autospec=True)
@@ -887,7 +889,8 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
 
     def test_vmedia_found_not_booted_from_vmedia(
             self, mock_execute, mock_mount, mock_copy,
-            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia):
+            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia,
+            mock_unmount_config):
         mock_booted_from_vmedia.return_value = False
         mock_find_device.return_value = '/dev/fake'
         utils.copy_config_from_vmedia()
@@ -896,10 +899,12 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
         mock_copy.assert_not_called()
         mock_check_vmedia.assert_not_called()
         self.assertTrue(mock_booted_from_vmedia.called)
+        self.assertTrue(mock_unmount_config.called)
 
     def test_no_vmedia(
             self, mock_execute, mock_mount, mock_copy,
-            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia):
+            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia,
+            mock_unmount_config):
         mock_booted_from_vmedia.return_value = True
         mock_find_device.return_value = None
         utils.copy_config_from_vmedia()
@@ -908,10 +913,12 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
         mock_copy.assert_not_called()
         mock_check_vmedia.assert_not_called()
         self.assertFalse(mock_booted_from_vmedia.called)
+        self.assertTrue(mock_unmount_config.called)
 
     def test_no_files(
             self, mock_execute, mock_mount, mock_copy,
-            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia):
+            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia,
+            mock_unmount_config):
         mock_booted_from_vmedia.return_value = True
         temp_path = tempfile.mkdtemp()
         self.addCleanup(lambda: shutil.rmtree(temp_path))
@@ -925,10 +932,12 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
                                              '/dev/something')
         mock_copy.assert_not_called()
         self.assertTrue(mock_booted_from_vmedia.called)
+        self.assertTrue(mock_unmount_config.called)
 
     def test_mounted_no_files(
             self, mock_execute, mock_mount, mock_copy,
-            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia):
+            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia,
+            mock_unmount_config):
 
         mock_booted_from_vmedia.return_value = True
         mock_execute.return_value = '/some/path', ''
@@ -939,11 +948,13 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
         mock_copy.assert_not_called()
         mock_mount.assert_not_called()
         self.assertTrue(mock_booted_from_vmedia.called)
+        self.assertTrue(mock_unmount_config.called)
 
     @mock.patch.object(os, 'makedirs', autospec=True)
     def test_copy(
             self, mock_makedirs, mock_execute, mock_mount, mock_copy,
-            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia):
+            mock_find_device, mock_check_vmedia, mock_booted_from_vmedia,
+            mock_unmount_config):
 
         mock_booted_from_vmedia.return_value = True
         mock_find_device.return_value = '/dev/something'
@@ -982,12 +993,14 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
             mock.call(mock.ANY, '/etc/ironic-python-agent.d/ironic.conf'),
         ], any_order=True)
         self.assertTrue(mock_booted_from_vmedia.called)
+        self.assertTrue(mock_unmount_config.called)
 
     @mock.patch.object(os, 'makedirs', autospec=True)
     def test_copy_mounted(
             self, mock_makedirs, mock_execute, mock_mount,
             mock_copy, mock_find_device, mock_check_vmedia,
-            mock_booted_from_vmedia):
+            mock_booted_from_vmedia,
+            mock_unmount_config):
         mock_booted_from_vmedia.return_value = True
         mock_find_device.return_value = '/dev/something'
         path = tempfile.mkdtemp()
@@ -1023,6 +1036,7 @@ class TestCopyConfigFromVmedia(testtools.TestCase):
         ], any_order=True)
         mock_mount.assert_not_called()
         self.assertTrue(mock_booted_from_vmedia.called)
+        self.assertTrue(mock_unmount_config.called)
 
 
 @mock.patch.object(requests, 'get', autospec=True)
@@ -1143,3 +1157,20 @@ class TestCheckEarlyLogging(ironic_agent_base.IronicAgentTest):
         expected_calls = [mock.call('Early logging: %s', 'line 1.'),
                           mock.call('Early logging: %s', 'line 2 message')]
         info.assert_has_calls(expected_calls)
+
+
+class TestUnmountOfConfig(ironic_agent_base.IronicAgentTest):
+
+    @mock.patch.object(utils, '_early_log', autospec=True)
+    @mock.patch.object(os.path, 'ismount', autospec=True)
+    @mock.patch.object(utils, 'execute', autospec=True)
+    @mock.patch.object(time, 'sleep', autospec=True)
+    def test__unmount_any_config_drives(self, mock_sleep, mock_exec,
+                                        mock_ismount, mock_log,):
+        mock_ismount.side_effect = iter([True, True, False])
+        utils._unmount_any_config_drives()
+        self.assertEqual(2, mock_sleep.call_count)
+        self.assertEqual(2, mock_log.call_count)
+        mock_exec.assert_has_calls([
+            mock.call('umount', '/mnt/config'),
+            mock.call('umount', '/mnt/config')])

ironic_python_agent/utils.py

@@ -311,18 +311,27 @@ def copy_config_from_vmedia():
         ['config-2', 'vmedia_boot_iso'])
     if not vmedia_device_file:
         _early_log('No virtual media device detected')
+        _unmount_any_config_drives()
         return
     if not _booted_from_vmedia():
         _early_log('Cannot use configuration from virtual media as the '
                    'agent was not booted from virtual media.')
+        _unmount_any_config_drives()
         return
     # Determine the device
     mounted = _find_mount_point(vmedia_device_file)
     if mounted:
+        # In this case a utility like a configuration drive tool
+        # has *already* mounted the device we believe to be the
+        # configuration drive.
         _copy_config_from(mounted)
     else:
         with ironic_utils.mounted(vmedia_device_file) as vmedia_mount_point:
+            # In this case, we use a temporary folder and extract the contents
+            # for our configuration.
             _copy_config_from(vmedia_mount_point)
+    # As a last act, just make sure there is nothing else mounted.
+    _unmount_any_config_drives()
 
 
 def _get_cached_params():
@@ -944,3 +953,22 @@ def find_in_lshw(lshw, by_id=None, by_class=None, recursive=False, **fields):
             yield child
         if recursive:
             yield from find_in_lshw(child, by_id, recursive=True, **fields)
+
+
+def _unmount_any_config_drives():
+    """Umount anything mounted to /mnt/config
+
+    As part of the configuration drive model, utilities like cloud-init
+    and glean leverage a folder at /mnt/config to convey configuration
+    to a booting OS.
+
+    The possibility exists that one of the utilties mounted one or multiple
+    such folders, even if the configuration was not used, and this can
+    result in locked devices which can prevent rebuild operations from
+    completing successfully as as long as the folder is mounted, it is
+    a "locked" device to the operating system.
+    """
+    while os.path.ismount('/mnt/config'):
+        _early_log('Issuing an umount command for /mnt/config...')
+        execute('umount', '/mnt/config')
+        time.sleep(1)

releasenotes/notes/always-make-sure-config-drive-is-umounted-a3985bbb45e89051.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Fixes an issue where configuration drive volumes which are mounted
+    by the operating system could remain mounted and cause a lock to be
+    held, which may conflict with actions such as ``rebuild``.
+    The agent now always makes sure the folder used by Glean and Cloud-init
+    is not mounted.