Add Ceph version check

CephFS drivers in OpenStack Manila are directing
mgr commands to the mgr by specifying mon-mgr as
the target [0]. This target (mon-mgr) was added
to Ceph in Octopus [1].

We would need a version check in order to set the
correct target while we wait on the backport on Ceph
to land [2].

[0] 3ea5d50a23
[1] 4000d500c0
[2] https://tracker.ceph.com/issues/51039

Closes-Bug: #1930459
Change-Id: I1a1079df8e104c5ddba29cb614eb4e02a304082e

manila/share/drivers/cephfs/driver.py

@@ -16,6 +16,7 @@
 
 import ipaddress
 import json
+import re
 import socket
 import sys
 
@@ -37,6 +38,7 @@ from manila.share.drivers import helpers as driver_helpers
 
 rados = None
 json_command = None
+ceph_default_target = None
 
 
 def setup_rados():
@@ -150,7 +152,7 @@ class RadosError(Exception):
 
 
 def rados_command(rados_client, prefix=None, args=None, json_obj=False,
-                  target=('mon-mgr', )):
+                  target=None):
     """Safer wrapper for ceph_argparse.json_command
 
     Raises error exception instead of relying on caller to check return
@@ -166,6 +168,9 @@ def rados_command(rados_client, prefix=None, args=None, json_obj=False,
             If json is False, return a decoded string (the data returned by
             ceph command)
     """
+
+    target = target or ceph_default_target
+
     if args is None:
         args = {}
 
@@ -216,7 +221,7 @@ class CephFSDriver(driver.ExecuteMixin, driver.GaneshaMixin,
         self._rados_client = None
         # name of the filesystem/volume used by the driver
         self._volname = None
-
+        self._ceph_mon_version = None
         self.configuration.append_config_values(cephfs_opts)
 
         try:
@@ -237,6 +242,8 @@ class CephFSDriver(driver.ExecuteMixin, driver.GaneshaMixin,
             protocol_helper_class = getattr(
                 sys.modules[__name__], 'NFSProtocolHelper')
 
+        self.setup_default_ceph_cmd_target()
+
         self.protocol_helper = protocol_helper_class(
             self._execute,
             self.configuration,
@@ -312,6 +319,44 @@ class CephFSDriver(driver.ExecuteMixin, driver.GaneshaMixin,
 
         return self.protocol_helper.get_export_locations(share, subvolume_path)
 
+    def setup_default_ceph_cmd_target(self):
+        global ceph_default_target
+        if not ceph_default_target:
+            ceph_default_target = ('mon-mgr', )
+
+            try:
+                ceph_major_version = self.ceph_mon_version['major']
+            except Exception:
+                msg = _("Error reading ceph version to set the default "
+                        "target. Please check your Ceph backend is reachable.")
+                raise exception.ShareBackendException(msg=msg)
+
+            if ceph_major_version == '14':
+                ceph_default_target = ('mgr', )
+            elif ceph_major_version < '14':
+                msg = _("CephFSDriver does not support Ceph "
+                        "cluster version less than 14.x (Nautilus)")
+                raise exception.ShareBackendException(msg=msg)
+
+    @property
+    def ceph_mon_version(self):
+        if self._ceph_mon_version:
+            return self._ceph_mon_version
+
+        self._ceph_mon_version = {}
+
+        output = rados_command(self.rados_client, "version", target=('mon', ))
+
+        version_str = json.loads(output)["version"]
+
+        p = re.compile(r"ceph version (\d+)\.(\d+)\.(\d+)")
+        major, minor, extra = p.match(version_str).groups()
+        self._ceph_mon_version['major'] = major
+        self._ceph_mon_version['minor'] = minor
+        self._ceph_mon_version['extra'] = extra
+
+        return self._ceph_mon_version
+
     @property
     def rados_client(self):
         if self._rados_client:

manila/tests/share/drivers/cephfs/test_driver.py

@@ -89,6 +89,8 @@ class CephFSDriverTestCase(test.TestCase):
         self.mock_object(driver, 'NativeProtocolHelper')
         self.mock_object(driver, 'NFSProtocolHelper')
 
+        driver.ceph_default_target = ('mon-mgr', )
+
         self._driver = (
             driver.CephFSDriver(execute=self._execute,
                                 configuration=self.fake_conf))
@@ -121,6 +123,37 @@ class CephFSDriverTestCase(test.TestCase):
 
         self.assertEqual(DEFAULT_VOLUME_MODE, self._driver._cephfs_volume_mode)
 
+    @ddt.data(
+        ('{"version": "ceph version 16.2.4"}', 'pacific'),
+        ('{"version": "ceph version 15.1.2"}', 'octopus'),
+        ('{"version": "ceph version 14.3.1"}', 'nautilus'),
+    )
+    @ddt.unpack
+    def test_version_check(self, ceph_mon_version, codename):
+        driver.ceph_default_target = None
+        driver.rados_command.return_value = ceph_mon_version
+
+        self._driver.do_setup(self._context)
+
+        if codename == 'nautilus':
+            self.assertEqual(('mgr', ), driver.ceph_default_target)
+        else:
+            self.assertEqual(('mon-mgr', ), driver.ceph_default_target)
+
+        driver.rados_command.assert_called_once_with(
+            self._driver.rados_client, "version", target=('mon', ))
+
+        self.assertEqual(1, driver.rados_command.call_count)
+
+    def test_version_check_not_supported(self):
+        driver.ceph_default_target = None
+        driver.rados_command.return_value = (
+            '{"version": "ceph version 13.0.1"}')
+
+        self.assertRaises(exception.ShareBackendException,
+                          self._driver.do_setup,
+                          self._context)
+
     @ddt.data('cephfs', 'nfs')
     def test_check_for_setup_error(self, protocol_helper):
         self._driver.configuration.cephfs_protocol_helper_type = (
@@ -551,6 +584,8 @@ class NativeProtocolHelperTestCase(test.TestCase):
 
         self.mock_object(driver, "rados_command")
 
+        driver.ceph_default_target = ('mon-mgr', )
+
         self._native_protocol_helper = driver.NativeProtocolHelper(
             None,
             self.fake_conf,
@@ -851,6 +886,8 @@ class NFSProtocolHelperTestCase(test.TestCase):
         self.mock_object(driver.socket, 'gethostname')
         self.mock_object(driver, "rados_command")
 
+        driver.ceph_default_target = ('mon-mgr', )
+
         self._nfs_helper = driver.NFSProtocolHelper(
             self._execute,
             self.fake_conf,
@@ -1172,6 +1209,8 @@ class CephFSDriverAltConfigTestCase(test.TestCase):
         self.mock_object(driver, 'NativeProtocolHelper')
         self.mock_object(driver, 'NFSProtocolHelper')
 
+        driver.ceph_default_target = ('mon-mgr', )
+
     @ddt.data('cephfs', 'nfs')
     def test_do_setup_alt_volume_mode(self, protocol_helper):
         self.fake_conf.set_default('cephfs_volume_mode', ALT_VOLUME_MODE)

releasenotes/notes/bug-1930459-add-ceph-version-check-88eee324bc6134ea.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    A Ceph version check has been added as part of this change to address
+    the absense of the mon-mgr target in Ceph Nautilus. With this change,
+    Ceph Nautilus users can leverage their storage backend with the
+    OpenStack manila Wallaby release.