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Re: modify dn while replication

Sorry but before playing with rewrite engine, I encontered basic problems just to replicate from master to slave through a proxy server :-(

here's the error message on the proxy server logs:
Feb 16 16:27:23 corbeau slapd[15683]: conn=0 op=1 MOD dn="uid=test,ou=People,dc=int-evry,dc=fr"
Feb 16 16:27:23 corbeau slapd[15683]: conn=0 op=1 MOD attr=userPassword homePostalAddress entryCSN modifiersName modifyTimestamp
Feb 16 16:27:23 corbeau slapd[15683]: conn=0 op=1 RESULT tag=103 err=19 text=entryCSN: no user modification allowed

slapd.conf: (running on localhost port 389) database bdb suffix "dc=int-evry, dc=fr" rootdn "cn=admin, dc=int-evry, dc=fr" rootpw secret directory /var/lib/ldap/int replica host= binddn="cn=replicator,ou=System,dc=int-evry,dc=fr" bindmethod=simple credentials=secret replogfile /var/lib/ldap/replica/replogfile

slapd_proxy.conf: (running on localhost port 8006) database ldap suffix "dc=int-evry,dc=fr" uri "ldap://";; lastmod on binddn cn=admin,dc=int-evry,dc=fr bindpw secret

slapd_slave.conf: (running on localhost port 9006)

database        bdb
suffix          "dc=int-evry,dc=fr"
rootdn          "cn=admin,dc=int-evry,dc=fr"
rootpw          secret
directory       /var/lib/ldap/int_slave
updatedn        "cn=replicator,ou=System,dc=int-evry,dc=fr"
updateref       "ldap://";

What a I doing wrong ?,

thanks .

Pierangelo Masarati wrote:

Pierangelo Masarati wrote:

It could be possible, but it's going to be rather clumsy;
it depends on whether there's a clear way you can extract
a filtering attribute from the DN, e.g. the "uid=<smtg>"
part, to do:

rewriteMap      ldap uidMap "ldap:///<naming context>?uid?sub"
rewriteRule     "^(uid=[^,]+)(,.*)$$" "%1-%{uidMap(%1)}%2" ":@I"

OK thanks a lot for the example :-), I'll try out, but before one
question, where should I put
these rewrite rules, in the replica section of the master ? this way :

replica         host=

bindmethod=simple   credentials=secret
               rewriteMap      ldap uidMap
               rewriteRule     "^(uid=[^,]+)(,.*)$$"
"%1-%{uidMap(%1)}%2" ":@I"
replogfile /var/lib/ldap/replica/replogfile

or on a dediceted ldap or meta backend ? sorry for beeing so ignorant,
but it's the first time I play with the rewrite engine ! by the way, I
suspect I need a " rewriteEngine on" somewhere, in slapd.conf ?

Sorry, my answer was incomplete. Yes, you need to replicate thru a proxy server, e.g. a server in between the master and the slave so that

master --> m2s-proxy: uid=test,... ==> uid=test-number,... --> slave

you need to figure out what you intend to do with referrals
from slave to master; if you need to rewrite as well, then
you need another proxy to revert the massaging.

slave --> s2m-proxy: uid=test-number,... ==> uid=test,... --> master

the proxy needs to be a back-ldap compiled with --enable-rewrite,
and needs to be configured with

database ldap
uri ldap://<slave>
lastmod on
rewriteEngine on
rewriteContext default
<rules as in example>


if the proxy is used also for normal operations,
you'll need to deal with other rewrite contexts,
e.g. searchBase, searchFilter, compareDN,
compareAttrDN if you want any rewriting to occur
in these cases.

you'll also need to deal with searchResults and more,
otherwise they'll be treated with the default rules.
see slapd-meta(5) in the REWRITE section for what
rewrite contexts are active.  otherwise you can add

rewriteContext searchBase
rewriteContext searchFilter
rewriteContext compareDN
rewriteContext compareAttrDN

rewriteContext searchResult
rewriteContext searchAttrDN
rewriteContext matchedDN

if you don't want any rewrite to occur for these
rewrite contexts.

On the contrary, the default rewriting should occur
for any write operation; the default naming context
is picked if you don't specify any.

Note: the "lastmod on" should work since the target
is a replica; it is important wince you want the
replica to be in sync with the master also in terms
of timestamps.