Docker kerberos

This image is for testing purposes for Kerberos/LDAP environments. With this Kerberos image you can initialize an Ubuntu based Kerberos server with LDAP connections. The whole project based on mrenouf/docker-images repository, but this codebase is not compatible with that.

Quick start

docker run -d --net docker_overlay -v /dev/urandom:/dev/random --name kerberos nugaon/kerberos-with-ldap

The containers have a pretty bad entropy level so the KDC won't start because of this. We can overcome this by using /dev/urandom which is less secure but does not care about entropy. Obviously, this Kerberos container has to be run on the same network as the ldap container or make it possible to reach the outsider LDAP server. For the former case, I suggest for you to use my compatible LDAP docker with Kerberos image nugaon/openldap-with-kerberos, that you can find on GitHub as well.

Useful environment variables:

Environment variables	Description	Default value
REALM	the Kerberos realm	EXAMPLE.COM
DOMAIN_REALM	the DNS domain for the realm	example.com
KERB_MASTER_KEY	master key for the KDC	masterkey
KERB_ADMIN_USER	administrator account name	admin
KERB_ADMIN_PASS	administrator's password	admin
SEARCH_DOMAINS	domain suffix search list	example.com
LDAP_DC	domain suffix search list	dc=example,dc=com
LDAP_USER	ldap service user	admin
LDAP_PASS	ldap service pass	admin
LDAP_URL	ldap url	ldap://ldap

Bind LDAP user to Kerberos DB

If you add new users in LDAP you have to register them in Kerberos as well in order to utilize Kerberos authentication. It is possible by the following command:

docker exec -ti $KERBEROS_CONTAINER kadmin.local -q 'addprinc -x dn=$USER_DN $USER_KERB_NAME'

example

docker exec -ti kerberos kadmin.local -q 'addprinc -x dn=cn=Teszt" "Elek,cn=users,dc=ldap,dc=hiflylabs,dc=hu telek'

Test

Once kerberos is enabled you need a ticket to execute any job on the cluster. Here's an example to get a ticket:

docker exec -ti kerberos sh -c "kinit admin && klist"

It authenticates the LDAP associated admin user by the Kerberos server.