CentOS - Aug 2017 - Centos 7 specific cure for Spamassassin DNS lookup problem

I have the following error message in my /var/log/spamd

spf: lookup failed: available_nameservers: No DNS servers available!

Having Googled the error message I've found a number of responses which 
involve patching Perl or Spamassassin or other cures. 

Before I start changing things I was wondering if there was a Centos 7 
specific resolution. Where possible, on production machines I prefer to stay 
with RPM's rather than amending software directly.

Also, many of these responses are over 10 years old, so I'm a little
sceptical
about their success today.

Gary

On Thursday 10 August 2017 09:21:31 Gary Stainburn
wrote:
> I have the following error message in my /var/log/spamd
>
> spf: lookup failed: available_nameservers: No DNS servers available!
>
> Having Googled the error message I've found a number of responses which
> involve patching Perl or Spamassassin or other cures.
>
> Before I start changing things I was wondering if there was a Centos 7
> specific resolution. Where possible, on production machines I prefer to
> stay with RPM's rather than amending software directly.
>
> Also, many of these responses are over 10 years old, so I'm a little
> sceptical about their success today.
One of the solutions that I've found is to add dns_server entries into the 
config file. As this did not entail updating the software this is the option 
I've chosen.

This has fixed the original 'spf' error message, but now gives me a
different
error message. I now get one or more 

Use of uninitialized value $rr_type in string eq 
at /usr/share/perl5/vendor_perl/Mail/SpamAssassin/Plugin/AskDNS.pm line 592.

I'm now looking into this one, but any assistance would be appreciated.

Gary
-- 
https://fundraise.cancerresearchuk.org/page/garys-march-march

On Thu, 10 Aug 2017, Gary Stainburn wrote:
> I have the following error message in my /var/log/spamd
> 
> spf: lookup failed: available_nameservers: No DNS servers available!
> 
> Having Googled the error message I've found a number of responses 
> which involve patching Perl or Spamassassin or other cures.
> 
> Before I start changing things I was wondering if there was a Centos 
> 7 specific resolution. Where possible, on production machines I 
> prefer to stay with RPM's rather than amending software directly.
I run SpamAssassin on CentOS 7; the SPF plugin is loaded via 
/etc/mail/spamassassin/init.pre. I have no trouble with spf at all.

Is it possible the problem is with local DNS resolution?

-- 
Paul Heinlein <> heinlein at madboa.com <> https://www.madboa.com/

On 10/08/17 15:37, Paul Heinlein wrote:
> On Thu, 10 Aug 2017, Gary Stainburn wrote:
> 
>> I have the following error message in my /var/log/spamd
>>
>> spf: lookup failed: available_nameservers: No DNS servers available!
>>
>> Having Googled the error message I've found a number of responses 
>> which involve patching Perl or Spamassassin or other cures.
>>
>> Before I start changing things I was wondering if there was a Centos 7 
>> specific resolution. Where possible, on production machines I prefer 
>> to stay with RPM's rather than amending software directly.
> 
> I run SpamAssassin on CentOS 7; the SPF plugin is loaded via 
> /etc/mail/spamassassin/init.pre. I have no trouble with spf at all.
> 
> Is it possible the problem is with local DNS resolution?
> 
Same here, no issues with spamassassin and SPF.

In addition to Paul's question which seems like the most obvious initial 
avenue of investigation, I assume you have perl-Mail-SPF and 
perl-Net-DNS installed? They should be as both are deps for the 
spamassassin package.

On 08/10/2017 01:21 AM, Gary Stainburn wrote:
> I have the following error message in my /var/log/spamd
>
> spf: lookup failed: available_nameservers: No DNS servers available!

Try starting spamassassin later.  Run "systemctl edit 
spamassassin.service" and insert two lines:

[Unit]
After=network-online.target

On Thursday 10 August 2017 18:45:32 Gordon Messmer
wrote:
> On 08/10/2017 01:21 AM, Gary Stainburn wrote:
> > I have the following error message in my /var/log/spamd
> >
> > spf: lookup failed: available_nameservers: No DNS servers available!
>
> Try starting spamassassin later.  Run "systemctl edit
> spamassassin.service" and insert two lines:
>
> [Unit]
> After=network-online.target

I will add the code, although updating RPM contents is one of the things I was 
trying to avoid.  Having said that, I have restarted the service after bootup 
has completed and this does not fix the problem.