Replace DNS client based on acutil with python-dns

IPA client and server tool set used authconfig acutil module to
for client DNS operations. This is not optimal DNS interface for
several reasons:
- does not provide native Python object oriented interface
  but but rather C-like interface based on functions and
  structures which is not easy to use and extend
- acutil is not meant to be used by third parties besides
  authconfig and thus can break without notice

Replace the acutil with python-dns package which has a feature rich
interface for dealing with all different aspects of DNS including
DNSSEC. The main target of this patch is to replace all uses of
acutil DNS library with a use python-dns. In most cases, even
though the larger parts of the code are changed, the actual
functionality is changed only in the following cases:
- redundant DNS checks were removed from verify_fqdn function
  in installutils to make the whole DNS check simpler and
  less error-prone. Logging was improves for the remaining
  checks
- improved logging for ipa-client-install DNS discovery

https://fedorahosted.org/freeipa/ticket/2730
https://fedorahosted.org/freeipa/ticket/1837

1 files changed, 1 insertions, 2 deletions

diff --git a/ipapython/README b/ipapython/README
index ec2bb3a52..a724a7faa 100644
--- a/ipapython/README
+++ b/ipapython/README
@@ -3,10 +3,9 @@ geared currently towards command-line tools.
 
 A brief overview:
 
-config.py - identify the IPA server domain and realm. It uses dnsclient to
+config.py - identify the IPA server domain and realm. It uses python-dns to
             try to detect this information first and will fall back to
             /etc/ipa/default.conf if that fails.
-dnsclient.py - find IPA information via DNS
 
 ipautil.py - helper functions