OpenLDAP-mailcow

Provision OpenLDAP accounts in mailcow-dockerized and enable LDAP authentication through Dovecot's LDAP integration.

How does it work
Usage
Limitations
- WebUI and EAS authentication
- Two-way sync
Customizations and Integration support
Credits

How does it work

A python script periodically checks and creates new LDAP accounts and deactivates deleted and disabled ones with mailcow API. It also enables LDAP authentication in SOGo and dovecot.

Usage

Prerequisites

Make sure that RDN identifier for user accounts in OpenLDAP is set to uid.

Setup

Create a data/ldap directory. SQLite database for synchronization will be stored there.

Extend your docker-compose.override.yml with an additional container:

 ldap-mailcow:
    image: nextboss/openldap-mailcow
    network_mode: host
    container_name: mailcowcustomized_ldap-mailcow
    depends_on:
        - nginx-mailcow
    volumes:
        - ./data/ldap:/db:rw
        - ./data/conf/dovecot:/conf/dovecot:rw
        - ./data/conf/sogo:/conf/sogo:rw
    environment:
        - LDAP-MAILCOW_LDAP_URI=ldap(s)://ldap.your-domain.com
        - LDAP-MAILCOW_LDAP_BASE_DN=DC=your-domain,DC=com
        - LDAP-MAILCOW_LDAP_BIND_DN=CN=admin,DC=your-domain,DC=com
        - LDAP-MAILCOW_LDAP_BIND_DN_PASSWORD=Ldap_BIND_passw0rd
        - LDAP-MAILCOW_API_HOST=https://mail.your-domain.com
        - LDAP-MAILCOW_API_KEY=<YOUR-MAILCOW-API-KEY>
        - LDAP-MAILCOW_SYNC_INTERVAL=300
        #- LDAP-MAILCOW_LDAP_FILTER=(&(objectClass=posixAccount))
        #- LDAP-MAILCOW_SOGO_LDAP_FILTER=objectClass='posixAaccount'
        - LDAP-MAILCOW_LDAP_FILTER=(&(objectClass=inetOrgPerson))
        - LDAP-MAILCOW_SOGO_LDAP_FILTER=objectClass='inetOrgPerson'

LDAP template fine-tuning

Change the following line in ./templates/dovecot/ldap/passdb.conf to fit your LDAP setup:

...
auth_bind_userdn = uid=%n,ou=People,dc=next-boss,dc=eu
...

Container internally uses the following configuration templates:

SOGo: /templates/sogo/plist_ldap
dovecot: /templates/dovecot/ldap/passdb.conf

These files have been tested against a docker-compose stack comprising of

running on Debian 11.

If necessary, you can edit and remount them through docker volumes. Some documentation on these files can be found here: dovecot, SOGo

Configure environmental variables:
- LDAP-MAILCOW_LDAP_URI - LDAP (e.g., Active Directory) URI (must be reachable from within the container). The URIs are in syntax protocol://host:port. For example ldap://localhost or ldaps://secure.domain.org
- LDAP-MAILCOW_LDAP_BASE_DN - base DN where user accounts can be found
- LDAP-MAILCOW_LDAP_BIND_DN - bind DN of a special LDAP account that will be used to browse for users
- LDAP-MAILCOW_LDAP_BIND_DN_PASSWORD - password for bind DN account
- LDAP-MAILCOW_API_HOST - mailcow API url. Make sure it's enabled and accessible from within the container for both reads and writes
- LDAP-MAILCOW_API_KEY - mailcow API key (read/write)
- LDAP-MAILCOW_SYNC_INTERVAL - interval in seconds between LDAP synchronizations
- Optional LDAP filters (see example above). SOGo uses special syntax, so you either have to specify both or none:
  - LDAP-MAILCOW_LDAP_FILTER - LDAP filter to apply, defaults to (&(objectClass=user)(objectCategory=person))
  - LDAP-MAILCOW_SOGO_LDAP_FILTER - LDAP filter to apply for SOGo (special syntax), defaults to objectClass='user' AND objectCategory='person'
Start additional container: docker-compose up -d ldap-mailcow
Check logs docker-compose logs ldap-mailcow
Restart dovecot and SOGo if necessary docker-compose restart sogo-mailcow dovecot-mailcow

Limitations

WebUI and EAS authentication

This tool enables authentication for Dovecot and SOGo, which means you will be able to log into POP3, SMTP, IMAP, and SOGo Web-Interface. You will not be able to log into mailcow UI or EAS using your LDAP credentials by default.

As a workaround, you can hook IMAP authentication directly to mailcow by adding the following code above this line:

    $mbox = imap_open ("{dovecot:993/imap/ssl/novalidate-cert}INBOX", $user, $pass);
    if ($mbox != false) {
        imap_close($mbox);
        return "user";
    }

As a side-effect, It will also allow logging into mailcow UI using mailcow app passwords (since they are valid for IMAP). It is not a supported solution with mailcow and has to be done only at your own risk!

Two-way sync

Users from your LDAP directory will be added (and deactivated if disabled/not found) to your mailcow database. Not vice-versa, and this is by design.

Customizations and Integration support

External authentication (identity federation) is an enterprise feature for mailcow. That’s why I developed an external solution, and it is unlikely that it’ll be ever directly integrated into mailcow.

I’ve created this tool because I needed it for my regular work. You are free to use it for commercial needs. Please understand that I can work on issues only if they fall within the scope of my current work interests or if I’ll have some available free time (never happened for many years). I’ll do my best to review submitted PRs ASAP, though.

You can always contact me to help you with the integration or for custom modifications on a paid basis. My current hourly rate (ActivityWatch tracked) is 120,-€ with 3h minimum commitment.

Buy Me a ☕

If you enjoy using this project and would like to show your support, please consider buying me a coffee ☕. As an open source developer, I rely on the support of the community to keep this project going.

❤️ Sponsor

Credits

This is a fork of the openldap-mailcow project with slight modifications to work with OpenLDAP out of the box.

sdotb/openldap-mailcow