symlinks deleted on upgrade, but not during reinstall

[John H]

----- Original Message -----
> From: Jeff Johnson <n3npq at mac.com>
> To: John H <uothrawn at yahoo.com>
> 
> On Sep 27, 2011, at 1:18 PM, John H wrote:
>>  ----- Original Message -----
>>>  From: Jeff Johnson <n3npq at mac.com>
>>>  To: John H <uothrawn at yahoo.com>
>>  
>>  How can I get ldconfig to not mess with my files ?
>> 
> 
> You need to supply a proper soname internal to the library.
> 
> This is (usually) done by passing -Wl,soname,foo to a linkage step somewhere.
> 
> What you seem to be attempting is adding some new symlinks to an
> older build of ldap (and so are wrestling with /sbin/ldconfig behavior).
> 
> There's more analysis needed with soname changes, which usually are 
> undertaken
> iff there's a serious incompatibility in the ABI that MUST be avoided.
> 
> I'm unaware of openldap development to "know" why soname changes 
> were undertaken.

CentOS 5.6 uses openldap-2.3. Version 2.3 uses the older (and often broken) slurpd method to replicate LDAP changes across nodes. We are using openldap-2.4 with a simple "make install" on CentOS 5.6 boxes currently. I'm attempting to make an openldap-2.4 RPM as a drop-in replacement for CentOS 5.6 servers. The issue is that openldap-2.3 (mostly the libldap-2.3.so.0 file) is a dependent of many other packages (pam, nss, passwd, etc).

This is why I'm trying to get my openldap-2.4 package to "Provide" the 2.3 shared objects--to satisfy that dependency and be a suitable upgrade to openldap-2.3.

The openldap-2.3 package has /etc/openldap/ldap.conf (and some other non-consequential manpages) as children files. So if I want to create an openldap-2.4 RPM, its starting to look like the best option would be to just exclude any file which is used by openldap-2.3 from my %files section.  This would result in a package something like openldap24-2.4.24 being installed alongside openldap-2.3. The final setup would look something like:

openldap-2.3.46
openldap24-2.4.24 (Requires: openldap-2.3.46)
openldap24-servers-2.4.24 (Conflicts: openldap-servers)
openldap24-clients-2.4.24 (Conflicts: openldap-clients)

The openldap24 packages would be missing a few OpenLDAP files to be considered standalone, thereby requiring the openldap-2.3 package.

Does this seem like the best solution?

Thanks.

> But this link
>     http://linuxtesting.org/upstream-tracker/
> is quite useful for finding the history of changes and incompatibilities.
> 
> SHort answer:
>     You likely need to build a newer version of ldap, not retrofit symlinks
>     (but that is just a guess here: I don't have sufficient info to say 
> anything for sure).
> 
>>>  What's likely happening is that running /sbin/ldconfig is removing 
> the 
>>>  symlinks.
>>> 
>>>  And the like (just guessing) reason is that the soname within the 
> library 
>>>  executable
>>>  disagrees with the symlinks you are attempting to package.
>>> 
>>>  Use readelf -a to display the internal SONAME.
>> 
>> 
>>  readelf -a gives an SONAME of libldap-2.4.so.2 for my libldap-2.3.so.0 
> symlink (as expected, given its a symlink). For the openldap-2.3.43 package, the 
> SONAME is libldap-2.3.so.0.  As one would expect... Is this a concern? 
> LDAP-based login functionality works if I have a symlink even though the SONAME 
> is wrong.
>> 
> 
> Hmm if the internal SONAME agrees with the versioning in the symlinks,
> then something else is going on.
> 
> You can always *remove* the symlinks from the package, and just let 
> /sbin/ldconfig
> create the symlinks. The only reason to include the sysmlinks in packages is
> to attempt to remove if/when a package is removed. These days /sbin/ldconfig
> mostly does that (but did not originally).
> 
> 
> hth
> 
> 73 de Jeff