python:tests: Tell dns.resolver to not read /etc/resolv.conf

We explicitly set the nameserver in the next line. Also the file
/etc/resolv.conf might not exist on the system (e.g in Fedora mockbuild).

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15308

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
(cherry picked from commit c4dba61e3691a1fd15eb63ee69224457102bf961)

diff --git a/python/samba/tests/blackbox/netads_dns.py b/python/samba/tests/blackbox/netads_dns.py
index 0a491504537209796e0c758e21ef3ac4c911738e..e9f945eaef91b3647d2e9e3a70bcd08bd445a917 100644 (file)
--- a/python/samba/tests/blackbox/netads_dns.py
+++ b/python/samba/tests/blackbox/netads_dns.py
@@ -30,7 +30,9 @@ class NetAdsDnsTests(BlackboxTestCase):
     def setUp(self):
         super(NetAdsDnsTests, self).setUp()
         nameserver = os.environ["DC_SERVER_IP"]
-        self.resolver = dns.resolver.Resolver()
+        # filename=None will disable reading /etc/resolv.conf. The file might
+        # not exist e.g. on build or CI systems.
+        self.resolver = dns.resolver.Resolver(filename=None)
         self.resolver.nameservers = [nameserver]
 
     def parse_output(self, output):