metamic/dovecot-ldap

A Docker image running Dovecot on Debian with LDAP backend

Docker dovecot-ldap

A Docker image running Dovecot on Debian stable ("jessie" at the moment) with the following modules:

• LMTP
• LDAP backend (with bind auth)

This image provide mailbox managment services. You can access those mailboxes using IMAP or POP protocols. Mails might be delivered using LMTP protocol.

Every mailbox access required an authenticated user. The user database is provided by an external LDAP service.

Interfaces

The image exposes several TCP ports. The IMAP and POP ports used to access to the mailboxes. The LMTP port to ship messages to the mailboxes:

• 143: IMAP port
• 993: IMAPs port
• 110: POP port
• 995: POPs port
• 24: LMTP port

Data persistence

The image exposes three directories:

• /var/mail: Actual mailboxes are stored in this volume. You should implement some backup strategies on those.
• /etc/ssl/localcerts: Service certificate and keys are stored in this volume. Dovecot is expecting the following PEM files: /etc/ssl/localcerts/imap.cert.pem and /etc/ssl/localcerts/imap.key.pem. If none are provided, the startup script will generate new keys and self-signed certificate.
• /etc/dovecot: If you want to override the default configurations, you can use this volume to make Dovecot use you files.

Usage

The most simple use would be to start the application like so :

docker run -d 
-p 143:143
--link ldap-container:ldap
-e LDAP_USER_FIELD="uid"
-e LDAP_BASE="ou=users,dc=yourdomain,dc=com"
-e LDAP_BIND_DN="cn=dovecot,dc=example,dc=com"
-e LDAP_BIND_DNPASS="password"
teid/dovecot-ldap

However, you should use your own certificate and a data-only container to store the mailboxes

docker run -d
-p 993:993
--link ldap-container:ldap
--volumes-from imap-certs
--volumes-from imap-data
-e LDAP_USER_FIELD="uid"
-e LDAP_BASE="ou=users,dc=yourdomain,dc=com"
-e LDAP_BIND_DN="cn=dovecot,dc=example,dc=com"
-e LDAP_BIND_DNPASS="password"
teid/dovecot-ldap

The following environment variables allows you to override some LDAP configurations:

• LDAP_BASE: The base dn of the LDAP users
• LDAP_BIND_DN (required): The bind dn of the LDAP user
• LDAP_BIND_DNPASS (required): The bind dn password of the LDAP user
• LDAP_USER_FIELD: The field name of your LDAP users used as username field
• SSL_KEY_PATH: The SSL private key path
• SSL_CERT_PATH: The SSL certificate path

Note: If you are using a custom configuration volume with this variables, your configuration files might be altered. You should not use both features.

The user are authenticated thanks to the user part of the address (user@domain). So the LDAP_USER_FIELD should contains the usernames without the address extensions. The LDAP auth will use the bind method