From 8276fa3c88f17744d65f53124b91b26c4c62d2d0 Mon Sep 17 00:00:00 2001
From: Victoria Martinez de la Cruz <victoria@redhat.com>
Date: Mon, 19 Sep 2022 08:32:42 +0000
Subject: [PATCH] Raise an exc if no VIP/backend is available

When deploying Manila CephFS NFS with cephadm,
the manila share service fails to start with the error
"Backend cephfsnfs supports neither IPv4 nor IPv6".

This happens because the NFS Ganesha daemon fails
to start for some reason and therefore the driver never
gets the location of the NFS Ganesha service
that will be used as the backend.

We should raise an error in this case with more information
about the failure.

This change adds this to the NFSClusterProtocol helper.

Closes-Bug: #1990150

Change-Id: Ic74c6c9d9770974848ec9dfb6d2225ce9b3bcb52
---
 manila/share/drivers/cephfs/driver.py         |  7 +++++++
 .../tests/share/drivers/cephfs/test_driver.py | 21 +++++++++++++++++++
 ...ails-start-raise-exc-7459302bf662fdd6.yaml | 12 +++++++++++
 3 files changed, 40 insertions(+)
 create mode 100644 releasenotes/notes/bug-1990150-cephadm-cephnfs-backend-fails-start-raise-exc-7459302bf662fdd6.yaml

diff --git a/manila/share/drivers/cephfs/driver.py b/manila/share/drivers/cephfs/driver.py
index 620b3703e6..f8c3fed1a1 100644
--- a/manila/share/drivers/cephfs/driver.py
+++ b/manila/share/drivers/cephfs/driver.py
@@ -1196,6 +1196,13 @@ class NFSClusterProtocolHelper(NFSProtocolHelperMixin, ganesha.NASHelperBase):
         else:
             export_ips.append(vip)
 
+        # there are no export IPs, there are no NFS servers we can use
+        if not export_ips:
+            msg = _("There are no NFS servers available to use. "
+                    "Please check the health of your Ceph cluster "
+                    "and restart the manila share service.")
+            raise exception.ShareBackendException(msg=msg)
+
         return export_ips
 
     def check_for_setup_error(self):
diff --git a/manila/tests/share/drivers/cephfs/test_driver.py b/manila/tests/share/drivers/cephfs/test_driver.py
index c53b113f25..f02b16b443 100644
--- a/manila/tests/share/drivers/cephfs/test_driver.py
+++ b/manila/tests/share/drivers/cephfs/test_driver.py
@@ -1265,6 +1265,27 @@ class NFSClusterProtocolHelperTestCase(test.TestCase):
         type(self._nfscluster_protocol_helper).nfs_clusterid = (
             mock.PropertyMock(return_value='fs-manila'))
 
+    def test_get_export_ips_no_backends(self):
+        fake_conf = configuration.Configuration(None)
+        cluster_info = {
+            "fs-manila": {
+                "virtual_ip": None,
+                "backend": []
+            }
+        }
+
+        driver.rados_command.return_value = json.dumps(cluster_info)
+
+        helper = driver.NFSClusterProtocolHelper(
+            self._execute,
+            fake_conf,
+            rados_client=self._rados_client,
+            volname=self._volname
+        )
+
+        self.assertRaises(exception.ShareBackendException,
+                          helper._get_export_ips)
+
     @ddt.data(constants.ACCESS_LEVEL_RW, constants.ACCESS_LEVEL_RO)
     def test_allow_access_rw_ro(self, mode):
         access_allow_prefix = "nfs export apply"
diff --git a/releasenotes/notes/bug-1990150-cephadm-cephnfs-backend-fails-start-raise-exc-7459302bf662fdd6.yaml b/releasenotes/notes/bug-1990150-cephadm-cephnfs-backend-fails-start-raise-exc-7459302bf662fdd6.yaml
new file mode 100644
index 0000000000..06ca022842
--- /dev/null
+++ b/releasenotes/notes/bug-1990150-cephadm-cephnfs-backend-fails-start-raise-exc-7459302bf662fdd6.yaml
@@ -0,0 +1,12 @@
+---
+fixes:
+  - |
+    When deploying Manila CephFS NFS with cephadm, the manila share
+    service fails to start with the error "Backend cephfsnfs supports
+    neither IPv4 nor IPv6". This happens because the NFS Ganesha
+    daemon fails to start for some reason, and therefore the driver
+    never gets the location of the NFS Ganesha service that will be
+    used as the backend. We rely on the operator to make sure the CephFS
+    NFS cluster is available when initializing the driver. With this fix in
+    place, we raise an exception to explicitly notify the operator and
+    allow them to take further action.