nss_ldap and openldap on the same server.

[Jonathan McKeown]

On Tuesday 13 March 2007 09:16, Gerhard Schmidt wrote:
> On Tue, Mar 13, 2007 at 12:07:15AM +0100, Pietro Cerutti wrote:
> > On 3/12/07, Gerhard Schmidt <estartu at augusta.de> wrote:
> > >Hi,
> >
> > Hello,
> >
> > >As I see it, nss asks all sources even if the frist one allready knows
> > > the answer. Is there a way to change this.
> >
> > man nsswitch.conf(5)
> > Look for Status codes and Actions
>
> Doesn't work. Tried the follwing nsswitch.conf
> group: files [success=return] ldap
> hosts: files dns
> networks: files
> passwd: files [success=return] ldap
> shells: files
>
> This doesn't change the delay. And the nss_ldap timeout is still reported.
> This is not supprising because the manpage states [success=return] is
> default.
>
> Seams there is a bug somewhere.

It's a well-known problem rather than a bug, and it arises when looking up 
group information for a user. The system needs a list of all the groups the 
user is a member of. Since it's a list, not a single answer, you can't 
short-circuit the process with ``success'' after finding a single result: 
initgroups(3) must work through all possible sources of group information to 
build the list.

The only ``workaround'' I've seen suggested is the parameter introduced 
recently in nss_ldap:

nss_initgroups_ignoreusers

It takes a comma-separated list of users for whom the nss_ldap initgroups 
routine should immediately return NSS_STATUS_NOTFOUND. If you keep group 
information for all the system users in /etc/group only, and add them all to 
this line in nss_ldap.conf, it should remove the problem. (Warning: I haven't 
tested this).

Jonathan