Prevent installation with single label domains

Adds validation to prevent user to install ipa with single label
domain.

https://pagure.io/freeipa/issue/7207

Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>

ipatests/test_xmlrpc/test_config_plugin.py

@@ -22,10 +22,12 @@
 Test the `ipaserver/plugins/config.py` module.
 """
 
-from ipalib import errors
+from ipalib import api, errors
 from ipatests.test_xmlrpc.xmlrpc_test import Declarative
 import pytest
 
+domain = api.env.domain
+sl_domain = 'singlelabeldomain'
 
 @pytest.mark.tier1
 class test_config(Declarative):
@@ -211,4 +213,18 @@ class test_config(Declarative):
                 summary=None,
                 ),
         ),
+        dict(
+            desc='Check if domain resolution order does not accept SLD',
+            command=(
+                'config_mod', [], {
+                    'ipadomainresolutionorder': u'{domain}:{sl_domain}'.format(
+                        domain=domain, sl_domain=sl_domain)}),
+            expected=errors.ValidationError(
+                name=u'ipadomainresolutionorder',
+                error=(
+                    u"Invalid domain name '{}': "
+                    "single label domains are not supported").format(
+                        sl_domain),
+            ),
+        ),
     ]

ipatests/test_xmlrpc/test_realmdomains_plugin.py

@@ -33,6 +33,7 @@ our_domain = api.env.domain
 new_domain_1 = u'example1.com'
 new_domain_2 = u'example2.com'
 bad_domain = u'doesnotexist.test'
+sl_domain = u'singlelabeldomain'
 
 
 @pytest.mark.tier1
@@ -280,4 +281,12 @@ class test_realmdomains(Declarative):
                 ),
             ),
         ),
+        dict(
+            desc='Add a single label domain {}'.format(sl_domain),
+            command=('realmdomains_mod', [], {'add_domain': sl_domain}),
+            expected=errors.ValidationError(
+                name='add_domain',
+                error='single label domains are not supported'
+            ),
+        )
     ]