FedFsOpenLdapServer0.9

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Revision as of 15:15, 9 October 2012

Project: fedfs-utils

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Configuring an OpenLDAP server for use with FedFS

The purpose of this article is to provide recipes for quickly setting up an NSDB service on an OpenLDAP server. If you are already familiar with OpenLDAP or have existing servers, browse this article to get a flavor for what is needed. Otherwise, follow the specific steps here to install and configure an NSDB.

These instructions are useful with Fedora 16 and following. A reference web article:

 http://docs.fedoraproject.org/en-US/Fedora/15/html/Deployment_Guide/ch-Directory_Servers.html

Uninstalling

If at any point you find the need to erase everything and start over, use:

# systemctl stop slapd.service
# systemctl disable slapd.service
# rm -rf /etc/openldap /var/lib/ldap

# yum erase openldap-servers openldap-clients

This removes all slapd instances and software.

Networking pre-requisites

Unless this LDAP server installation will be accessed only via localhost, the hosting OS must be assigned a fixed IP address with a consistent forward and reverse DNS mapping.

On some RH-based distributions, networking doesn't start until a user logs in on the console. If this is the case, configure the system's network to start automatically.

By default on modern RH-based distributions, an IP-based firewall is enabled during a typical install. Allow other systems to access the LDAP service on this machine by adjusting the firewall configuration. On Fedora 16, the firewall configurator is at Applications -> Other -> Firewall. You can poke a hole for LDAP in the "Other Ports" section. Be sure to open "ldap," "ldaps," and "ldap-admin." Or disable the firewall entirely if you are sure that's safe to do.

Install OpenLDAP server package

After installing, updating, and configuring Fedora, install the OpenLDAP server components with:

# yum install openldap openldap-clients openldap-servers

This command adds a new UID and GID, which is user and group "ldap", (55, 55).

Copy in the DB_CONFIG file (why doesn't the package install do this automatically?)

# cp /usr/share/openldap-servers/DB_CONFIG.example /var/lib/ldap/DB_CONFIG
# chown ldap.ldap /var/lib/ldap/DB_CONFIG

Install the fedfs schema

Extract the FedFS schema from the LDAP/NSDB draft. Copy the result to /etc/openldap/schema/fedfs.schema. Ensure that the security context, group, owner, and mode bits match the other files in this directory. See also:

 http://www.openldap.org/doc/admin/schema.html

or

 http://www.zytrax.com/books/ldap/ch6/slapd-config.html

Create an encrypted administrator password

This step generates the value of the LDAP administrator password, but doesn't actually set it. The purpose of this step is to ensure that the password is stored by LDAP as an encrypted value.

$ slappasswd
New password:
Re-enter new password:
{SSHA}MP0BeMJzmCoCi5olBhwcRDYJaGBFgN5K

Copy the final encrypted output (e.g. {SSHA}MP0BeMJzmCoCi5olBhwcRDYJaGBFgN5K) for use below.

For an NSDB that will be used during testing events on secure networks, an easy-to-type well-known administrator password is advised. "test123" or "cthon201x" are typical values. Otherwise, a stronger password is recommended.

Generally, separate passwords are created for "cn=config" and the entity that administers the DIT under dc=... . Repeat the steps above to generate a second password, if desired.

Configure the LDAP server

Install the sample configuration file

# cp /usr/share/openldap-servers/slapd.conf.obsolete /etc/openldap/slapd.conf

Edit this file:

1. Just after "database config", add:
   1. rootdn "cn=admin,cn=config"
   2. rootpw <your hashed PW created above>
2. Replace "dc=my-domain,dc=com" everywhere with your local domain name
3. Just after "database hdb", add:
   1. rootdn "cn=Manager,dc=your-domain,dc=net"
   2. rootpw <your hashed password created above>
4. Merge the FedFS schema
   1. Either add an include directive for the fedfs.schema file added above
   2. Or use the LDAP OLC configuration tool in fedfs-utils/contrib/ldap to add the schema dynamically after the server is running

Test the new configuration:

# slaptest -u -f /etc/openldap/slapd.conf

Correct any errors before continuing. Then build the new configuration:

# cd /etc/openldap
# rm -rf slapd.d/* ; mkdir slapd.d ; chown ldap.ldap slapd.d
# sudo -u ldap slaptest -f ./slapd.conf -F ./slapd.d
# mv slapd.conf slapd.conf.bak

Create an entry for the dc naming context

This initializes a standard domain entry under the dc=... root suffix you created above. This prepares the LDAP server for the creation of other entries under this suffix. This step can be skipped if you are not planning to add entries (including any FedFS-related entries) under this suffix.

slapd must be stopped. On the LDAP server, edit the file /tmp/ldif and add only these lines:

dn: dc=your-domain,dc=net
objectClass: domain
dc: your-domain

Then run these commands:

# sudo -u ldap slapadd -l /tmp/ldif

Create a database for a top-level FedFS context

This prepares the LDAP server for the creation of a top-level NCE. Skip this step if you're planning to place your FedFS-related entries under some other root suffix.

Run these commands:

# mkdir /path/to/database
# chown -R ldap.ldap /path/to/database

Use the "add-database-olc" sample script in fedfs-utils/contrib/ldap. Edit it as needed (see comments inside the script).

Configure logging

First:

# touch /var/log/slapd
# chown ldap:ldap /var/log/slapd

Edit /etc/rsyslog.conf and add a line like this: "local4.* /var/log/slapd" and restart rsyslogd.

In /etc/sysconfig/ldap, uncomment the SLAPD_OPTIONS line, and add "-s ###" where the ### is some set of or'd flags indicating what you'd like logged. Log level options are described in slapd.conf(5). A useful level of logging is 768.

Restart slapd.

Start the server

To start the server once:

# systemctl start slapd.service

To start the server automatically during system boot:

# systemctl enable slapd.service

To stop the server once:

# systemctl stop slapd.service

To prevent the server from starting during system boot:

# systemctl disable slapd.service