2996cc8 tests: Configure DNSResolver as platform agnostic resolver

1 file Authored by slev a year ago, Committed by frenaud a year ago,
    tests: Configure DNSResolver as platform agnostic resolver
    
    Avoid reading platform specific `/etc/resolv.conf` in `TestDNSResolver`
    unit tests. Systems (e.g. sandboxes) may not have `/etc/resolv.conf`
    or this file may not contain any configured name servers.
    
    `TestDNSResolver` unit tests check only customized `nameservers`
    property and should not depend on existence of `/etc/resolv.conf`.
    
    Resolver accepts `configure` option.
    https://dnspython.readthedocs.io/en/latest/resolver-class.html :
    > configure, a bool. If True (the default), the resolver instance is
      configured in the normal fashion for the operating system the resolver
      is running on. (I.e. by reading a /etc/resolv.conf file on POSIX
      systems and from the registry on Windows systems.)
    
    Fixes: https://pagure.io/freeipa/issue/9319
    Signed-off-by: Stanislav Levin <slev@altlinux.org>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>