DNS fix: do not traceback if unsupported records are in LDAP

Show records which are unsupported, if they are in LDAP.
Those records are not editable, and web UI doesnt show them.

Fixes traceback caused by --structured option

Ticket: https://fedorahosted.org/freeipa/ticket/4930
Reviewed-By: Petr Spacek <pspacek@redhat.com>

ipalib/plugins/dns.py

@@ -976,6 +976,17 @@ class ForwardRecord(DNSRecord):
                         reason=_('Cannot create reverse record for "%(value)s": %(exc)s') \
                                 % dict(value=record, exc=unicode(e)))
 
+class UnsupportedDNSRecord(DNSRecord):
+    """
+    Records which are not supported by IPA CLI, but we allow to show them if
+    LDAP contains these records.
+    """
+    supported = False
+
+    def _get_part_values(self, value):
+        return tuple()
+
+
 class ARecord(ForwardRecord):
     rrtype = 'A'
     rfc = 1035
@@ -1023,10 +1034,9 @@ class AFSDBRecord(DNSRecord):
         ),
     )
 
-class APLRecord(DNSRecord):
+class APLRecord(UnsupportedDNSRecord):
     rrtype = 'APL'
     rfc = 3123
-    supported = False
 
 class CERTRecord(DNSRecord):
     rrtype = 'CERT'
@@ -1062,10 +1072,9 @@ class CNAMERecord(DNSRecord):
         ),
     )
 
-class DHCIDRecord(DNSRecord):
+class DHCIDRecord(UnsupportedDNSRecord):
     rrtype = 'DHCID'
     rfc = 4701
-    supported = False
 
 class DNAMERecord(DNSRecord):
     rrtype = 'DNAME'
@@ -1076,10 +1085,9 @@ class DNAMERecord(DNSRecord):
         ),
     )
 
-class DNSKEYRecord(DNSRecord):
+class DNSKEYRecord(UnsupportedDNSRecord):
     rrtype = 'DNSKEY'
     rfc = 4034
-    supported = False
 
 class DSRecord(DNSRecord):
     rrtype = 'DS'
@@ -1114,20 +1122,18 @@ class DLVRecord(DSRecord):
     rfc = 4431
 
 
-class HIPRecord(DNSRecord):
+class HIPRecord(UnsupportedDNSRecord):
     rrtype = 'HIP'
     rfc = 5205
-    supported = False
 
-class KEYRecord(DNSRecord):
+class KEYRecord(UnsupportedDNSRecord):
+    # managed by BIND itself
     rrtype = 'KEY'
     rfc = 2535
-    supported = False  # managed by BIND itself
 
-class IPSECKEYRecord(DNSRecord):
+class IPSECKEYRecord(UnsupportedDNSRecord):
     rrtype = 'IPSECKEY'
     rfc = 4025
-    supported = False
 
 class KXRecord(DNSRecord):
     rrtype = 'KX'
@@ -1300,20 +1306,19 @@ class NSRecord(DNSRecord):
         ),
     )
 
-class NSECRecord(DNSRecord):
+class NSECRecord(UnsupportedDNSRecord):
+    # managed by BIND itself
     rrtype = 'NSEC'
     rfc = 4034
-    supported = False  # managed by BIND itself
 
-class NSEC3Record(DNSRecord):
+class NSEC3Record(UnsupportedDNSRecord):
     rrtype = 'NSEC3'
     rfc = 5155
-    supported = False
 
-class NSEC3PARAMRecord(DNSRecord):
+class NSEC3PARAMRecord(UnsupportedDNSRecord):
+    # this is part of zone in IPA
     rrtype = 'NSEC3PARAM'
     rfc = 5155
-    supported = False  # this is part of zone in IPA
 
 def _validate_naptr_flags(ugettext, flags):
     allowed_flags = u'SAUP'
@@ -1365,10 +1370,9 @@ class PTRRecord(DNSRecord):
         ),
     )
 
-class RPRecord(DNSRecord):
+class RPRecord(UnsupportedDNSRecord):
     rrtype = 'RP'
     rfc = 1183
-    supported = False
 
 class SRVRecord(DNSRecord):
     rrtype = 'SRV'
@@ -1403,20 +1407,19 @@ def _sig_time_validator(ugettext, value):
         return _('the value does not follow "YYYYMMDDHHMMSS" time format')
 
 
-class SIGRecord(DNSRecord):
+class SIGRecord(UnsupportedDNSRecord):
+    # managed by BIND itself
     rrtype = 'SIG'
     rfc = 2535
-    supported = False  # managed by BIND itself
 
-class SPFRecord(DNSRecord):
+class SPFRecord(UnsupportedDNSRecord):
     rrtype = 'SPF'
     rfc = 4408
-    supported = False
 
-class RRSIGRecord(SIGRecord):
+class RRSIGRecord(UnsupportedDNSRecord):
+    # managed by BIND itself
     rrtype = 'RRSIG'
     rfc = 4034
-    supported = False  # managed by BIND itself
 
 class SSHFPRecord(DNSRecord):
     rrtype = 'SSHFP'
@@ -1445,9 +1448,8 @@ class SSHFPRecord(DNSRecord):
         return tuple(values)
 
 
-class TARecord(DNSRecord):
+class TARecord(UnsupportedDNSRecord):
     rrtype = 'TA'
-    supported = False
 
 
 class TLSARecord(DNSRecord):
@@ -1475,13 +1477,11 @@ class TLSARecord(DNSRecord):
     )
 
 
-class TKEYRecord(DNSRecord):
+class TKEYRecord(UnsupportedDNSRecord):
     rrtype = 'TKEY'
-    supported = False
 
-class TSIGRecord(DNSRecord):
+class TSIGRecord(UnsupportedDNSRecord):
     rrtype = 'TSIG'
-    supported = False
 
 class TXTRecord(DNSRecord):
     rrtype = 'TXT'