Re: Building an LDAP database "for dummies"

[Howard Chu <hyc@symas.com>]

Jonathan Coles wrote:

> In trying to learn how to create an LDAP database, my head is spinning 
> with all the verbiage about trees, DN, CN, DC, slapd.conf, ldap.conf and 
> so on. Is there a simple working example with an LDIF file, slapd.conf, 
> and ldap.conf file that could get me started?
>
> No matter what I try, ldapadd always complains that there is "No such 
> object". The error message is useless as it doesn't tell me which 
> object. And, of course, some of the objects don't exist because I'm 
> trying to define them! Catch-22.
>
> What I'm reading in the documentation and in this group tells me that 
> the database has a "tree" structure that must match in the database and 
> the queries. What is this tree? Is it the schema files that are included 
> into slapd.conf? Or is it the DN, CN, objectClass statements in the LDIF 
> file I use to create the database? Or, is something else I don't yet 
> know about?

Have you ever used the Domain Name System? (Yes, obviously.) Do you 
understand the notion of a "hierarchical namespace"? Surely you've 
already been heavily exposed to it, the filesystem on the computer 
you're typing on is most likely hierarchical as well. LDAP/X.500 is no 
different, these are all directories of one form or another and they all 
 store data in a similar fashion.

In DNS there are "TLDs" (Top Level Domains) - .com, .edu, .org, .us, 
etc... Other subdomains are created underneath these domains, e.g. 
openldap.org. There can be arbitrarily many subdomains nested in this 
fashion, e.g. "room8.level6.LosAngeles.ca.MyCompany.com" and there can 
be various other entries inside a subdomain e.g. 
"printer1.room8.level6.LosAngeles.ca.MyCompany.com", printer2..., and so on.

In creating any hierarchical tree, you have to start at the root node 
and work your way down. You can't create "MyCompany.com" if ".com" 
doesn't exist yet. You can't create "CA.MyCompany.com" until 
"MyCompany.com" has been created.

Just like in a filesystem directory - to create /usr/local/lib/gcc you 
first have to make sure that /usr, /usr/local, and /usr/local/lib exist 
first, in that order.

So - "What is this tree?" - the tree is the structure you design to 
contain the data you're going to store. Schema is just a description of 
what kinds of data will be recognized by the server, but it doesn't say 
anything about the location of the data. The tree structure gives you 
the location.
--
  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc
  Symas: Premier OpenSource Development and Support