From e63c68d505ee2eb88a0edef83c4a63a8d827f9f6 Mon Sep 17 00:00:00 2001
From: Alex Kavanagh <alex.kavanagh@canonical.com>
Date: Fri, 7 May 2021 12:13:29 +0100
Subject: [PATCH] Fix bug where str is added to cached_hostset list

The original code was appending a str to a list rather than either
appending it or adding it as a list of one element.  The code avoids
append to avoid unintentional side-effects.

Change-Id: I1466981f1d68f8dea3bbe32fdde6c4825056c0d0
Closes-Bug: #1927698
---
 hooks/nova_cc_utils.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/hooks/nova_cc_utils.py b/hooks/nova_cc_utils.py
index ff3628f7..a6d4cdb6 100644
--- a/hooks/nova_cc_utils.py
+++ b/hooks/nova_cc_utils.py
@@ -1367,7 +1367,10 @@ def resolve_hosts_for(private_address, hostname):
         if (not ch_ip.is_ipv6(private_address) and
                 hostname and
                 hostname not in cached_hostset):
-            return cached_hostset + hostname
+            hosts = cached_hostset + [hostname]
+            db.set(db_key, hosts)
+            db.flush()
+            return hosts
         return cached_hostset
 
     # Use a set to enforce uniqueness; order doesn't matter