[Pure Storage] Fix connection issue on network failure.

Retry the login process if a network issue has caused the connection to
the FlashBlade to fail.

Use the periodic task to update share stats to catch this.

Closes-bug: #2032681
Change-Id: Ic4be90aba729978e24bdd808ba1130d05aed9985

manila/share/drivers/purestorage/flashblade.py

@@ -197,7 +197,19 @@ class FlashBladeShareDriver(driver.ShareDriver):
         super(FlashBladeShareDriver, self)._update_share_stats(data)
 
     def _get_available_capacity(self):
-        space = self._sys.arrays.list_arrays_space()
+        try:
+            space = self._sys.arrays.list_arrays_space()
+        except purity_fb.rest.ApiException:
+            message = "Connection failure. Retrying login..."
+            LOG.warning(message)
+            try:
+                self._sys.login(self.api)
+                self._sys._api_client.user_agent = self._user_agent
+            except purity_fb.rest.ApiException as ex:
+                msg = _("Exception when logging into the array: %s\n") % ex
+                LOG.exception(msg)
+                raise exception.ManilaException(message=msg)
+            space = self._sys.arrays.list_arrays_space()
         array_space = space.items[0]
         data_reduction = array_space.space.data_reduction
         physical_capacity_bytes = array_space.capacity

releasenotes/notes/bug-2032681-flashblade-relogin-f1781c6bdb15df71.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Pure Storage FlashBlade driver: Retry login for periodic task should
+    network issue cause loss of connection. See `launchpad bug 2032681
+    <https://bugs.launchpad.net/manila/+bug/2032681>`_ for more details.