Migrating some of the main services configuration from plain text files to a LDAP backend.
(This is a skeleton to get some initial ideas and resources. Much work and decissions have to be done)
Configs that might be moved:
DCHPD
There are two real possible aproaches:
Using a cron script that fetches information from LDAP and re-create dhcpd configs. There is some previous art work. Not tested at all recently.
- Patching dhcpd3-server to be able to use LDAP as a backend:
A patched version of the current Lenny dhcp3-server version is available at http://linex.educarex.es/dhcpd-ldap/ . The package is called dhcp3-server-ldap, and has the same patch Gosa has but upgraded to this dhcpd version. It includes a dhcpd.schema with its documentation
Implementing dhcp3-server-ldap
These steps supposse that:
- dhcp3-server is configured and running in the server
- There is a ldap server available
- The ldap suffix is "dc=instituto,dc=extremadura,dc=es" (replace it with your suffix, as "dc=skole,dc=skolelinux,dc=no")
- ldap server is running at the ip 172.16.3.166 (replace it with your ip or hostname)
- dhcpd server is running at aula1-pro (replace it with your hostname)
At the dhcp server:
- Install the package dhcp3-server-ldap from Debian lenny or sid.
- To get the ldif with the dhcp information:
dhcpd-conf-to-ldap.pl --basedn "dc=instituto,dc=extremadura,dc=es" \ --dhcpdn "cn=DHCP Config, dc=instituto,dc=extremadura,dc=es" \ --conf "/etc/dhcp3/dhcpd.conf" >dhcpd.ldif
- Change dhcpd configuration, so the /etc/dhcp3/dhcpd.conf file should be like this:
ldap-server "172.16.3.166"; ldap-port 389; ldap-base-dn "dc=instituto,dc=extremadura,dc=es"; ldap-debug-file "/var/log/dhcp-ldap-startup.log"; ldap-dhcp-server-cn "aula1-pro"; ldap-method dynamic; ddns-update-style none;
Notes:
- ip reservations have to be placed directly under the DHCP Config entry tree
At the ldap server:
- Bring from the dhcp server the dhcpd.ldif file from the step 1 above and the file /usr/share/doc/dhcp3-server-ldap/dhcp.schema.gz
- Gunzip dhcp.schema.gz and copy it to /etc/ldap/schema/
- Edit /etc/ldap/ldap.conf and add these lines:
include /etc/ldap/schema/dhcp.schema index dhcpHWAddress eq index dhcpClassData eq
- Import dhcpd.ldif into ldap tree using your favourite application (gq, phpldapadmin, ldapadd, etc.)
- Reindex and restart ldap server:
slapindex & /etc/init.d/slapd restart
Now restart dhcpd server and take a look at "/var/log/dhcp-ldap-startup.log". If everything goes fine, the old dhcpd.config file should be there, but extracted from ldap, and dhcp should be working.
DNS
Alternatives: powerdns(pdns-backend-ldap) ldapdns ldap2dns ldap2zone
Ldap2dns
a tool that generates zone files out of ldap data, contains it's own schema called dns.schema
Powerdns
The currently most advanced aproximation is using PowerDNS with a ldap backend. Packages are available in Debian to implement it.
powerdns's best advantage is that it uses ldap directly. That means that there is no need for cronjobs and scripts to convert ldap data into config files, before reloading services.
schema requirements. the standard cosine.schema (allready in our config) implements most dns requirements. The exception beeing PTR records that are needed for revers lookups. In order to support the PTR record, one must add the dnsdomain2.schema included in the pdns-backend-ldap package.
implementing powerdns
In order to test powerdns on your own installation you can follow these instructions.
- backup your bind configuration
tar -czvf /skole/backup/bind.tgz /etc/bind /var/cache/bind
- install the powerdns packages.
aptitude install pdns-backend-ldap pdns-doc pdns-recursor pdns-server
- Write the powerdns configuration
Add this as the file etc/powerdns/pdns.d/pdns-debian-edu.conf
# LDAP server configuration # Do not use a hostname here, unless you also add that name to the /etc/hosts file. ldap-host=10.0.2.2 ldap-method=tree ldap-basedn=ou=hosts,dc=skole,dc=skolelinux,dc=no #start the ldap backend on boot. launch=ldap #ACL that allow recursion from this server, and the network. allow-recursion=10.0.2.0/23, 127.0.0.1 #Only recurse if question cannot be answered locally lazy-recursion=yes #IP Addresses of recursive nameservers, eg your ISP's servers. This example uses the pdns-recursor running localy on a custom port. recursor=127.0.0.1:1553
- Configure pdns-recursor to run on a custom port.
Edit the file /etc/powerdns/recursor.conf and edit so it contains the line local-port=1553
- add a needed ldap schema to your openLDAP configuration.
- Add the line
include /etc/ldap/schema/dnsdomain2.schema
in the file /etc/ldap/slapd.conf under # Schema and objectClass definitions
- Add the line
- restart slapd
- create ldif files from bind configuration. Take notice that this creates a identical copy of your dns setting from your bind config. One of the reasons one might want to keep configurations in ldap is to reduce clutter, And only have the hosts one actualy needs, in the zone. I imagine that the new default zone file would be empty , except for the services aliases. And that the zone would be populated when one starts to add hosts in the admin tool.
zone2ldap --basedn=ou=hosts,dc=skole,dc=skolelinux,dc=no --layout=tree --zone-file=/etc/bind/debian-edu/db.intern --zone-name=intern > dns-intern.ldif
... FIXME: add more about migration ...
add the ldif's to the openldap server using ldapadd -c -Z -f your-ldif-file-here.ldif -x -D 'cn=admin,ou=People,dc=skole,dc=skolelinux,dc=no' -W -h 10.0.2.2
- FIXME: You may (or may not) have to create the ou=hosts container first.
- restart the pdns-recursor, and verify it's running on port 1553.
- restart pdns
For cd-lenny-test-dvd/debian-edu-amd64-i386-DVD-1.iso Build 2009-04-13T11:44 powerdns is installed but I must additional add the public ldap key with:
cd /etc/ldap/ssl/ openssl req -new -x509 -days 3650 -key slapd.pem -out ldap-server-pubkey.pem
Start of ldif files made by hand for skolelinux with powerdns.
dn: ou=hosts,dc=skole,dc=skolelinux,dc=no objectClass: organizationalUnit objectClass: domainRelatedObject ou: hosts associatedDomain: intern dn: dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dcobject objectclass: dnsdomain objectclass: domainrelatedobject dc: intern soarecord: ns.intern root@intern 1 1800 3600 86400 7200 nsrecord: ns.intern mxrecord: 10 mail.intern associateddomain: intern dn: dc=tjener,dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain objectclass: domainrelatedobject dc: tjener arecord: 10.0.2.2 associateddomain: tjener.intern dn: dc=gateway,dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain objectclass: domainrelatedobject dc: gateway arecord: 10.0.2.1 associateddomain: gateway.intern dn: dc=ldap,dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain objectclass: domainrelatedobject dc: ldap cnamerecord: tjener.intern associateddomain: ldap.intern dn: dc=www,dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain objectclass: domainrelatedobject dc: www
And the reverse file:
dn: dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain2 objectclass: domainrelatedobject dc: arpa associateddomain: arpa dn: dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain2 objectclass: domainrelatedobject dc: in-addr associateddomain: in-addr.arpa dn: dc=10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain2 objectclass: domainrelatedobject dc: 10 associateddomain: 10.in-addr.arpa dn: dc=0,dc=10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain2 objectclass: domainrelatedobject dc: 0 associateddomain: 0.10.in-addr.arpa dn: dc=2,dc=0,dc=10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain2 objectclass: domainrelatedobject dc: 2 associateddomain: 2.0.10.in-addr.arpa dn: dc=2,dc=2,dc=0,dc=10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain2 objectclass: domainrelatedobject dc: 2 ptrrecord: tjener.intern associateddomain: 2.2.0.10.in-addr.arpa dn: dc=1,dc=2,dc=0,dc=10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no objectclass: top objectclass: dnsdomain2 objectclass: domainrelatedobject dc: 1 ptrrecord: gateway.intern associateddomain: 1.2.0.10.in-addr.arpa
lts.conf
Fetching LTSP client config from ldap. allows for LTSP server clusters. There are some vague ideas and old implementations available:
LTSP enhancements : "Migration path from lts.conf to lts.conf and LDAP implemented. lts.conf is still required to indicate the LDAP info for the workstation. Once all items ([Default] and workstation specific) are in LDAP, then LDAP is the preferred location to gather configuration settings from."
motivation / why?
Why are you doing this ? LDAP makes sense for user-accounts - I agree. But why did you put dhcpd.conf into LDAP ? One thing I love about UNIX & Linux are the plaintext configuration files: easy to read and easy to edit. LDAP is like the Windows registry: a binary database, you need tools to edit it. Changing settings becomes very hard. With SSL/TS even more harder. 
To permit to be able create web interfaces to delegate to non technical peoples do some tasks. To improve availability and maintenance, because data will be stored in centered way.