Fix URLField to allow numbers in top level domain

Add a custom regex to URLField that allows numbers to be present in the
top level domain, e.g. https://towerhost.org42

Set by variable allow_numbers_in_top_level_domain in URLField __init__,
and is set to True by default. If set to False, it will use the regex
specified in the built-in django URLValidator class.

This solution was originally implemented in LDAPServerURIField, but is
now implemented in URLField to support this behavior more generally. The
changes in LDAPServerURIField are longer needed and have been removed in
this commit.

Adds unit testing to make sure URLField changes handle regex input
and settings correctly.

awx/sso/fields.py

@@ -11,7 +11,6 @@ import awx
 # Django
 from django.utils import six
 from django.utils.translation import ugettext_lazy as _
-from django.core.validators import URLValidator, _lazy_re_compile
 
 # Django Auth LDAP
 import django_auth_ldap.config
@@ -234,34 +233,12 @@ class AuthenticationBackendsField(fields.StringListField):
 
 class LDAPServerURIField(fields.URLField):
 
-    tld_re = (
-        r'\.'                                              # dot
-        r'(?!-)'                                           # can't start with a dash
-        r'(?:[a-z' + URLValidator.ul + r'0-9' + '-]{2,63}' # domain label, this line was changed from the original URLValidator
-        r'|xn--[a-z0-9]{1,59})'                            # or punycode label
-        r'(?<!-)'                                          # can't end with a dash
-        r'\.?'                                             # may have a trailing dot
-    )
-
-    host_re = '(' + URLValidator.hostname_re + URLValidator.domain_re + tld_re + '|localhost)'
-
-    regex = _lazy_re_compile(
-        r'^(?:[a-z0-9\.\-\+]*)://'  # scheme is validated separately
-        r'(?:[^\s:@/]+(?::[^\s:@/]*)?@)?'  # user:pass authentication
-        r'(?:' + URLValidator.ipv4_re + '|' + URLValidator.ipv6_re + '|' + host_re + ')'
-        r'(?::\d{2,5})?'  # port
-        r'(?:[/?#][^\s]*)?'  # resource path
-        r'\Z', re.IGNORECASE)
-
     def __init__(self, **kwargs):
-
         kwargs.setdefault('schemes', ('ldap', 'ldaps'))
         kwargs.setdefault('allow_plain_hostname', True)
-        kwargs.setdefault('regex', LDAPServerURIField.regex)
         super(LDAPServerURIField, self).__init__(**kwargs)
 
     def run_validators(self, value):
-
         for url in filter(None, re.split(r'[, ]', (value or ''))):
             super(LDAPServerURIField, self).run_validators(url)
         return value