Updated to be MUCH more usable.

dns_compare.py

@@ -1,28 +1,81 @@
 #!/usr/bin/env python
 
 import argparse
+from shlex import join
 import dns.query
+import dns.rdatatype
+import dns.name
+import json
 import re
 
+# Get list of supported record types
+supported_types = sorted([dns.rdatatype.to_text(rdtype) for rdtype in dns.rdatatype.RdataType])
+
 parser = argparse.ArgumentParser()
 parser.add_argument('--domain', help='Helps if all records to query are on the same domain.')
 parser.add_argument('--nameservers', nargs='+', help='IPv4 or IPv6 address of nameserver(s) to be queried.')
-parser.add_argument('--records', nargs='+', help='Hostname to query.')
+parser.add_argument('--records', nargs='*', help='Hostname(s) to query. If not provided with --domain, queries the domain itself.')
+parser.add_argument('--record-type', default='A', help='DNS record type to query. Default: A')
+parser.add_argument('--list-record-types', action='store_true', help='Print list of supported record types and exit.')
 args = parser.parse_args()
 
+# Handle listing record types
+if args.list_record_types:
+    print("Supported DNS record types:")
+    for rtype in supported_types:
+        print(f"  {rtype}")
+    exit(0)
+
+# Convert record type string to dns.rdatatype constant
+try:
+    record_type = dns.rdatatype.from_text(args.record_type)
+except dns.rdatatype.UnknownRdatatype:
+    print(f"Error: Unknown record type '{args.record_type}'")
+    print(f"\nSupported record types:")
+    print((', ').join(supported_types))
+    exit(1)
+
+# Build the output structure
+output = {}
+
+# Determine what to query
 if args.domain:
-    for rec in args.records:
-        qname = dns.name.from_text(f'{rec}.{args.domain}')
-        q = dns.message.make_query(qname, dns.rdatatype.A)
+    # If records are provided, use them as subdomains; otherwise use the domain itself
+    records_to_query = args.records if args.records else [args.domain]
+    
+    for rec in records_to_query:
+        if rec == args.domain:
+            full_domain = args.domain
+        else:
+            full_domain = f'{rec}.{args.domain}'
+        qname = dns.name.from_text(full_domain)
+        q = dns.message.make_query(qname, record_type)
+        output[full_domain] = {"records": {}}
         for ns in args.nameservers: 
             r = dns.query.udp(q, ns)
-            x = re.findall(fr'{str(rec)}.*', str(r))
-            print(x, ns)
+            # Extract the resolved IP address from the response
+            answers = r.answer
+            if answers:
+                for rrset in answers:
+                    for item in rrset:
+                        output[full_domain]["records"][ns] = str(item)
 else:
+    # Query each record as a full domain
+    if not args.records:
+        print("Error: Either --domain or --records must be provided")
+        exit(1)
+    
     for rec in args.records:
         qname = dns.name.from_text(rec)
-        q = dns.message.make_query(qname, dns.rdatatype.A)
+        q = dns.message.make_query(qname, record_type)
+        output[rec] = {"records": {}}
         for ns in args.nameservers: 
             r = dns.query.udp(q, ns)
-            x = re.findall(fr'{str(rec)}.*', str(r))
-            print(x, ns)
+            # Extract the resolved IP address from the response
+            answers = r.answer
+            if answers:
+                for rrset in answers:
+                    for item in rrset:
+                        output[rec]["records"][ns] = str(item)
+
+print(json.dumps(output, indent=4))