dnsdist: Gracefully handle missing v6 in backend discovery test

This test has been randomly failing on GH actions lately, and it looks
like it is because we sometimes do not get the IPv6 addresses when
resolving `dns.quad9.net` via the system resolver.

diff --git a/regression-tests.dnsdist/test_BackendDiscovery.py b/regression-tests.dnsdist/test_BackendDiscovery.py
index 645bc59be8e047794cbb6a98da40a1fff5dade34..49dd50d26eb60db1baf63e212d256ffc7934af30 100644 (file)
--- a/regression-tests.dnsdist/test_BackendDiscovery.py
+++ b/regression-tests.dnsdist/test_BackendDiscovery.py
@@ -439,13 +439,19 @@ class TestBackendDiscoveryByHostname(DNSDistTest):
             self.assertTrue(len(tokens) == 13 or len(tokens) == 14)
             backends[tokens[1]] = tokens[2]
 
-        if len(backends) != 4:
+        if len(backends) == 4:
+            for expected in ['9.9.9.9:53', '149.112.112.112:53', '[2620:fe::9]:53', '[2620:fe::fe]:53']:
+                self.assertIn(expected, backends)
+        elif len(backends) == 2:
+            # looks like we are not getting the IPv6 addresses, thanks GitHub!
+            for expected in ['9.9.9.9:53', '149.112.112.112:53']:
+                self.assertIn(expected, backends)
+        else:
             return False
 
-        for expected in ['9.9.9.9:53', '149.112.112.112:53', '[2620:fe::9]:53', '[2620:fe::fe]:53']:
-            self.assertIn(expected, backends)
         for backend in backends:
-            self.assertTrue(backends[backend])
+            self.assertEqual(backends[backend], 'up')
+
         return True
 
     def testBackendFromHostname(self):