[Samba] Printing with smbspool_krb5_wrapper not working in Ubuntu 16.04

[Van Svensson]

> > I should have mentioned this earlier, but the users does not exist
> > in /etc/passwd, instead they are in LDAP and when they log in to the
> > computer they get some Kerberos tickets for the domain and the file
> > system. When printing on 14.04 they get another Kerberos ticket for
> > the printing system according to "klist" after they have done "lpr"
> > and printed a document. On 16.04 nothing is printed and the user gets
> > no Kerberos ticket for the printing system and the job is left in
> > "lpq".
> 
> Are your main users running Windows ?
> Are they members of an AD domain ?

At my part of the organization most people are running Linux: Ubuntu 14.04 LTS. Right now I am trying to upgrade to Ubuntu 16.04 LTS but after the upgrade the printing does no longer work. Centrally at the organization they are running Windows and we Linux users are using the centrally provided printing system through SMB-Kerberos. Everything works fine in 14.04. After upgrading to 16.04 everything works except the printing.

As I mentioned earlier I see that double backslashes are used in 16.04 when SMBSPOOL_KRB5 is setting KRB5CCNAME, can that cause this problem?
Ubuntu 16.04 /var/log/cups/error_log: SMBSPOOL_KRB5 - Setting KRB5CCNAME to \'FILE:/tmp/krb5cc_1000\'
Ubuntu 14.04 /var/log/cups/error_log: SMBSPOOL_KRB5 - Setting KRB5CCNAME to 'FILE:/tmp/krb5cc_1000'

Do you have any idea about what the error "HTTP_STATE_WAITING Closing for error 32 (Broken pipe)" can tell me in this situation when it is printed right after SMBSPOOL_KRB5 has set KRB5CCNAME?

Also wondering about why I get this right after the above error: "Could not determine network interfaces, you must use a interfaces config line"

(As a side note, not sure if it is interesting, but I see in the /var/log/cups/error_log that SMBSPOOL_KRB5 sets KRB5CCNAME to /tmp/krb5cc_UID (where UID is >= 1000). In our environment the user gets /tmp/krb5cc_UID_RANDOM (where RANDOM is a random string) from Heimdal Kerberos when logging in so in 14.04 (where printing works) you have to create a symbolic link from /tmp/krb5cc_UID to /tmp/krb5cc_UID_RANDOM to have the printing work which we do through a small script in /etc/profile.d/. Maybe this has been fixed in later versions of Samba so that we do not need to create this symbolic link for each user? (Of course I have checked that this symbolic link creation works in 16.04.))

Thanks / Van