Bug#833296: exim4-config: dpkg-reconfigure exim4-config: misleading message

[Marc Haber]

On Wed, Aug 03, 2016 at 10:26:57AM +0200, Mauro Salvini wrote:
> > > > If uname() returns a single-component name, Exim calls gethostbyname()
> > > > (or getipnodebyname() where available) in an attempt to acquire a
> > > > fully qualified host name.
> > > > 
> > > > Can you check what your gethostbyname/getipnodebyname returns?
> > 
> > > hostname by uname(): myhostname
> > > hostname by gethostbyname(): myhostname.mydomain.local
> > 
> > Hm.
> > 
> > What does hostname --fqdn say?
> 
> It says myhostname.mydomain.local

Good.

> > What does exim -bP | grep ^primary_hostname say?
> 
> It says myhostname

not good.

> Checked /var/lib/exim4/config.autogenerated for primary_hostname:
> 
> .ifdef MAIN_HARDCODE_PRIMARY_HOSTNAME
> primary_hostname = MAIN_HARDCODE_PRIMARY_HOSTNAME
> .endif
> 
> MAIN_HARDCODE_PRIMARY_HOSTNAME never defined

So primary_hostname is set according to the docs
(/usr/share/doc/exim4-base/spec.txt.gz):

$primary_hostname

    This variable contains the value set by primary_hostname in the
    configuration file, or read by the uname() function. If uname() returns a
    single-component name, Exim calls gethostbyname() (or getipnodebyname()
    where available) in an attempt to acquire a fully qualified host name. See
    also $smtp_active_hostname.

The last sentence doesn't apply here. And we see that your
gethostbyname returns the host name just fine.

What does getent hosts $IP for all your IP addresses say?

> > and 192.168.0.10 is your local IP address on the network?
> 
> No , I obfuscate it, sorry. It actually is 10.0.xx.xx

Same thing, a RFC 1918 address that is unlikely to have correct
reverse DNS.

> > Is your "myhostname.mydomain.local" the literal host name? If so, are
> > you actually using the .local TLD or is that just obfuscated? Please
> > consider using a different TLD as .local may cause interference with
> > avahi (the .local TLD is reserved for use with mDNS).
> 
> Yes, domain ends with .local (this name comes from IT&C office
> configuration).
> 
> Just for a try, I changed /etc/hosts and /etc/mailname to have a .net
> TLD:
> - exim -bP | grep ^primary_hostname says
>   myhostname

Bad.

> - exim -bt -d+all username says
>   10:13:17  5455 local_part=username domain=myhostname.mydomain.net
>   10:13:17  5455 checking domains
>   10:13:17  5455 myhostname.mydomain.net in "@:localhost"? no (end of
> list)

Looks better, but why? Strangely, the process of qualifying the
address is not in the debug output, first thing I see of the username
is its already qualified form.

Greetings
Marc

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