Why is dnspython giving me this error?

Question

Here is my simple code:

    print host
    for rdata in dns.resolver.query(host, 'CNAME') :
      prod_host = str(rdata.target)

I'm pulling host out of a file. When I run this, I get the following:

"www.maizena.es"
Traceback (most recent call last):
  File "lexparse.py", line 488, in <module>
dfs(rules_tree)
  File "lexparse.py", line 486, in dfs
dfs(child)
  File "lexparse.py", line 486, in dfs
dfs(child)
  File "lexparse.py", line 471, in dfs
for rdata in dns.resolver.query(host, 'CNAME') :
  File "build/bdist.macosx-10.11-intel/egg/dns/resolver.py", line 1132, in query
  File "build/bdist.macosx-10.11-intel/egg/dns/resolver.py", line 1051, in query
dns.resolver.NXDOMAIN: None of DNS query names exist: \"www.maizena.es\"., \"www.maizena.es\".masked.domain.com., \"www.maizena.es\".domain.com., \"www.maizena.es\".netarch.domain.com., \"www.maizena.es\".fr.adsvc., \"www.maizena.es\".domainlab.com.

What's odd is that when I run a test in the python repl it seems to work as expected:

bos-mpqpu:config_parse rabdelaz$ python
Python 2.7.10 (default, Oct 23 2015, 19:19:21) 
[GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.0.59.5)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import dns.resolver
>>> for rdata in dns.resolver.query("www.maizena.es", 'CNAME') :
...     prod_host = str(rdata.target)
... 
>>> prod_host
'sana.kona.unilever.com.edgekey.net.'

Furthermore, the dns resolution from my command line works just fine:

$ dig www.maizena.es

; <<>> DiG 9.8.3-P1 <<>> www.maizena.es
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 15148
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.maizena.es.            IN  A

;; ANSWER SECTION:
www.maizena.es.     138 IN  CNAME   sana.kona.unilever.com.edgekey.net.
sana.kona.unilever.com.edgekey.net. 154 IN CNAME e10923.x.akamaiedge.net.
e10923.x.akamaiedge.net. 20 IN  A   96.6.167.93

;; Query time: 73 msec
;; SERVER: 172.27.112.15#53(172.27.112.15)
;; WHEN: Tue Jul 25 11:24:11 2017
;; MSG SIZE  rcvd: 130

Any insight appreciated.

Are those other domains from your config file? .fr.adsvc, .netarch.domain.com, domainlab.com and such? Those look real odd to me. — captncraig, Jul 25 '17 at 15:25
my *guess* is those are in my local DNS resolver since I'm on the domain.com VPN. — Ramy, Jul 25 '17 at 15:26
ok. makes sense. Is it possibly querying different nameservers in repl vs from a script? — captncraig, Jul 25 '17 at 15:27
i haven't modified any of the settings in dns.resolver in my script. So I don't see how, but maybe there's something about the module I don't understand. — Ramy, Jul 25 '17 at 15:28
Can you get it to fail in the repl, and see if it is maybe using a different path or version of the lib? — captncraig, Jul 25 '17 at 15:30
I had some extraneous double quotes in there. sorry for the false alarm — Ramy, Jul 25 '17 at 15:36

score 2 · Answer 1 · answered Jul 15 '20 at 18:48

I faced the same issue dns.resolver.NXDOMAIN: None of DNS query names exist: but it was not related to the redundant double quotes.

Because this question is first answer from the search engine for that kind of error, I hope my answer will be helpful for the people who faced the same issue as mine.

You can try to use your current default DNS Server to query the DNS records. It's fixed the issue for me.

Open cmd.exe and run commands below:

ipconfig /all | findstr /R "DNS\ Servers"

C:\>ipconfig /all | findstr /R "DNS\ Servers"
   DNS Servers . . . . . . . . . . . : 223.121.180.100
   DNS Servers . . . . . . . . . . . : 223.121.180.101

Take first DNS Server IP address and set it as a nameserver for the resolver, as an additional nameservers you can set one from Google and one from Cloudflare.

my_resolver = dns.resolver.Resolver(configure=False)
my_resolver.nameservers = ['223.121.180.100', '8.8.8.8', '1.1.1.1']
answer = my_resolver.query('google.com', 'A')

score 1 · Accepted Answer · answered Jul 25 '17 at 15:36

Issue here is the string actually has double quotes embedded in it. I need to strip those out.

Notice: \"www.maizena.es\" in the error message.

I modified my script like this:

    print repr(host)
    for rdata in dns.resolver.query(host[1:-1], 'CNAME') :
      prod_host = str(rdata.target)

using print repr() helped identify the extraneous double quotes.

Why is dnspython giving me this error?

2 Answers2