feat(linstorvolumemanager): cache controller uri in a file

drivers/LinstorSR.py

@@ -13,7 +13,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
+from linstorvolumemanager import write_controller_uri_cache
 from sm_typing import Optional, override
 
 from constants import CBTLOG_TAG
@@ -420,6 +420,7 @@ def connect():
                                 try:
                                     util.SMlog('Connecting from config to LINSTOR controller using: {}'.format(ip))
                                     create_linstor(controller_uri, attempt_count=0)
+                                    write_controller_uri_cache(controller_uri)
                                     return controller_uri
                                 except:
                                     pass

drivers/linstor-manager

@@ -350,8 +350,7 @@ def detach(session, args):
         vdi_uuid = args['vdiUuid']
         group_name = args['groupName']
 
-        linstor = LinstorVolumeManager(
-            get_controller_uri(),
+        linstor = LinstorVolumeManager.create_from_cache(
             group_name,
             logger=util.SMlog
         )
@@ -405,8 +404,7 @@ def get_vhd_info(session, args):
         group_name = args['groupName']
         include_parent = util.strtobool(args['includeParent'])
 
-        linstor = LinstorVolumeManager(
-            get_controller_uri(),
+        linstor = LinstorVolumeManager.create_from_cache(
             group_name,
             logger=util.SMlog
         )
@@ -440,8 +438,7 @@ def get_parent(session, args):
         device_path = args['devicePath']
         group_name = args['groupName']
 
-        linstor = LinstorVolumeManager(
-            get_controller_uri(),
+        linstor = LinstorVolumeManager.create_from_cache(
             group_name,
             logger=util.SMlog
         )
@@ -594,8 +591,7 @@ def deflate(session, args):
         zeroize = util.strtobool(args['zeroize'])
         group_name = args['groupName']
 
-        linstor = LinstorVolumeManager(
-            get_controller_uri(),
+        linstor = LinstorVolumeManager.create_from_cache(
             group_name,
             logger=util.SMlog
         )
@@ -619,8 +615,7 @@ def lock_vdi(session, args):
         if locked:
             lock.acquire()
 
-        linstor = LinstorVolumeManager(
-            get_controller_uri(),
+        linstor = LinstorVolumeManager.create_from_cache(
             group_name,
             logger=util.SMlog
         )
@@ -678,8 +673,7 @@ def add_host(session, args):
             )
 
     # 3. Ensure node doesn't exist.
-    linstor = LinstorVolumeManager(
-        get_controller_uri(),
+    linstor = LinstorVolumeManager.create_from_cache(
         group_name,
         logger=util.SMlog
     )
@@ -781,8 +775,7 @@ def remove_host(session, args):
             pbds[pbd_ref] = pbd
 
     # 2. Remove node.
-    linstor = LinstorVolumeManager(
-        get_controller_uri(),
+    linstor = LinstorVolumeManager.create_from_cache(
         group_name,
         logger=util.SMlog
     )
@@ -1127,8 +1120,7 @@ def create_node_interface(session, args):
 
     ip_addr = get_ip_addr_of_pif(session, pif_uuid)
 
-    linstor = LinstorVolumeManager(
-        get_controller_uri(),
+    linstor = LinstorVolumeManager.create_from_cache(
         group_name,
         logger=util.SMlog
     )
@@ -1144,8 +1136,7 @@ def destroy_node_interface(session, args):
     hostname = args['hostname']
     name = args['name']
 
-    linstor = LinstorVolumeManager(
-        get_controller_uri(),
+    linstor = LinstorVolumeManager.create_from_cache(
         group_name,
         logger=util.SMlog
     )
@@ -1164,8 +1155,7 @@ def modify_node_interface(session, args):
 
     ip_addr = get_ip_addr_of_pif(session, pif_uuid)
 
-    linstor = LinstorVolumeManager(
-        get_controller_uri(),
+    linstor = LinstorVolumeManager.create_from_cache(
         group_name,
         logger=util.SMlog
     )
@@ -1180,8 +1170,7 @@ def list_node_interfaces(session, args):
     group_name = args['groupName']
     hostname = args['hostname']
 
-    linstor = LinstorVolumeManager(
-        get_controller_uri(),
+    linstor = LinstorVolumeManager.create_from_cache(
         group_name,
         logger=util.SMlog
     )
@@ -1195,8 +1184,7 @@ def get_node_preferred_interface(session, args):
     group_name = args['groupName']
     hostname = args['hostname']
 
-    linstor = LinstorVolumeManager(
-        get_controller_uri(),
+    linstor = LinstorVolumeManager.create_from_cache(
         group_name,
         logger=util.SMlog
     )
@@ -1211,8 +1199,7 @@ def set_node_preferred_interface(session, args):
     hostname = args['hostname']
     name = args['name']
 
-    linstor = LinstorVolumeManager(
-        get_controller_uri(),
+    linstor = LinstorVolumeManager.create_from_cache(
         group_name,
         logger=util.SMlog
     )

drivers/linstorjournaler.py

@@ -17,7 +17,8 @@
 
 
 from linstorvolumemanager import \
-  get_controller_uri, LinstorVolumeManager, LinstorVolumeManagerError
+    get_controller_uri, LinstorVolumeManager, LinstorVolumeManagerError, build_controller_uri_cache, \
+    delete_controller_uri_cache
 import linstor
 import re
 import util
@@ -160,8 +161,10 @@ def connect(uri):
 
         try:
             return connect(uri)
-        except (linstor.errors.LinstorNetworkError, LinstorVolumeManagerError):
+        except LinstorVolumeManagerError:
             pass
+        except linstor.errors.LinstorNetworkError:
+            delete_controller_uri_cache()
 
         return util.retry(
             lambda: connect(None),

drivers/linstorvolumemanager.py

@@ -43,6 +43,10 @@
 
 DRBD_BY_RES_PATH = '/dev/drbd/by-res/'
 
+CONTROLLER_CACHE_DIRECTORY = os.environ.get('TMPDIR', '/tmp') + '/linstor'
+CONTROLLER_CACHE_FILE = 'controller_uri'
+CONTROLLER_CACHE_PATH = "{}/{}".format(CONTROLLER_CACHE_DIRECTORY, CONTROLLER_CACHE_FILE)
+
 PLUGIN = 'linstor-manager'
 
 
@@ -196,18 +200,57 @@ def _get_controller_uri():
         # Not found, maybe we are trying to create the SR...
         pass
 
-def get_controller_uri():
-    retries = 0
-    while True:
+
+def get_cached_controller_uri():
+    try:
+        with open(CONTROLLER_CACHE_PATH, "r") as f:
+            return f.read().strip()
+    except Exception as e:
+        util.SMlog('Unable to read controller uri cache file at {} : {}'.format(
+            CONTROLLER_CACHE_PATH,
+            e
+        ))
+    return None
+
+def delete_controller_uri_cache():
+    try:
+        os.remove(CONTROLLER_CACHE_PATH)
+    except Exception as e:
+        util.SMlog('Unable to write controller uri cache file at {} : {}'.format(
+            CONTROLLER_CACHE_PATH,
+            e
+        ))
+
+def write_controller_uri_cache(uri):
+    try:
+        if not os.path.exists(CONTROLLER_CACHE_DIRECTORY):
+            os.makedirs(CONTROLLER_CACHE_DIRECTORY)
+            os.chmod(CONTROLLER_CACHE_DIRECTORY, 0o700)
+        if not os.path.isdir(CONTROLLER_CACHE_DIRECTORY):
+            raise NotADirectoryError
+        with open(CONTROLLER_CACHE_PATH, "w") as f:
+            f.write(uri)
+    except Exception as e:
+        util.SMlog('Unable to write controller uri cache file at {} : {}'.format(
+            CONTROLLER_CACHE_PATH,
+            e
+        ))
+
+
+def build_controller_uri_cache():
+    for _ in range(10):
         uri = _get_controller_uri()
         if uri:
+            write_controller_uri_cache(uri)
             return uri
-
-        retries += 1
-        if retries >= 10:
-            break
         time.sleep(1)
+    return None
 
+def get_controller_uri():
+    uri = get_cached_controller_uri()
+    if not uri:
+        uri = build_controller_uri_cache()
+    return uri
 
 def get_controller_node_name():
     PLUGIN_CMD = 'hasControllerRunning'
@@ -429,6 +472,34 @@ def __init__(
         self._volume_info_cache_dirty = True
         self._build_volumes(repair=repair)
 
+    @staticmethod
+    def create_from_cache(
+        group_name, repair=False, logger=default_logger.__func__,
+        attempt_count=30
+    ):
+        """
+        Attempt to create a LinstorVolumeManager from cached data.
+        If it fails, refresh the cache and retry once.
+
+        :param str group_name: The SR goup name to use.
+        :param bool repair: If true we try to remove bad volumes due to a crash
+        or unexpected behavior.
+        :param function logger: Function to log messages.
+        :param int attempt_count: Number of attempts to join the controller.
+        """
+        uri = get_cached_controller_uri()
+        if not uri:
+            uri = build_controller_uri_cache()
+        if not uri:
+            raise LinstorVolumeManagerError(
+                "Unable to retrieve a valid controller URI from cache or after rebuild."
+            )
+
+        return LinstorVolumeManager(
+            uri, group_name, repair=repair,
+            logger=logger, attempt_count=attempt_count
+        )
+
     @property
     def group_name(self):
         """
@@ -2598,7 +2669,7 @@ def _get_error_str(cls, result):
 
     @classmethod
     def _create_linstor_instance(
-        cls, uri, keep_uri_unmodified=False, attempt_count=30
+        cls, uri, keep_uri_unmodified=False, keep_cache_on_error=False, attempt_count=30
     ):
         retry = False
 
@@ -2615,8 +2686,11 @@ def connect(uri):
 
         try:
             return connect(uri)
-        except (linstor.errors.LinstorNetworkError, LinstorVolumeManagerError):
+        except LinstorVolumeManagerError:
             pass
+        except linstor.errors.LinstorNetworkError:
+            if not keep_cache_on_error:
+                build_controller_uri_cache()
 
         if not keep_uri_unmodified:
             uri = None

drivers/tapdisk-pause

@@ -31,7 +31,7 @@ import lvmcache
 
 try:
     from linstorvhdutil import LinstorVhdUtil
-    from linstorvolumemanager import get_controller_uri, LinstorVolumeManager
+    from linstorvolumemanager import LinstorVolumeManager
     LINSTOR_AVAILABLE = True
 except ImportError:
     LINSTOR_AVAILABLE = False
@@ -163,8 +163,7 @@ class Tapdisk:
             dconf = session.xenapi.PBD.get_device_config(pbd)
             group_name = dconf['group-name']
 
-            linstor = LinstorVolumeManager(
-                get_controller_uri(),
+            linstor = LinstorVolumeManager.create_from_cache(
                 group_name,
                 logger=util.SMlog
             )