Ansible role to set up a mail server

This ansible role installs a mail server as described in this blog post by Thomas Leistner.

SSL

SSL certificates and keys are expected in /etc/myssl/$FQDN.crt and /etc/myssl/$FQDN.crt on the mail host (where $FQDN is the hosts FQDN). This can be change by setting the {{ ssl_directory }}, {{ ssl_directory }} or {{ ssl_directory }} variable to a different path. If these files do not exist, a self-signed certificate will be created for initial use, these are not recommended for a production setup. If you require a certificate signed by a trusted CA, try Let's Encrypt.

Variables

The following variables have to be set by you in order to use this role:

Variable	Explanation
dbserver_root_pw	password for the root user of the database
mailserver_sql_vmail_password	password for the vmail user in the database
milter_sql_spamass_password	password for the spamassassin user in the database
mailserver_hostname	hostname of the mail server (e.g. mail)
mailserver_domain	domain of the mail server (e.g. example.com)

A lot more variables are available to customize the mail server installation, you can find them in the defaults/main.yml of this role and its dependencies.

Passwords

Instead of saving passwords in plain-text in vars/vars.yml, consider using the ansible vault.

For a quick-start to the vault, you can execute ansible-vault create vars/vault.yml and fill it like so:

mailserver_sql_vmail_password: foo
milter_sql_spamass_password: bar
dbserver_root_pw: baz

(Replace foo, bar and baz with secure passwords)

Now, whenever you run a playbook with this role, remember to use the --ask-vault-pass with ansible-playbook.

Deployment

Before deployment, you must set passwords for the database users (see above). Also this playbook assumes a default installation of Ubuntu Server 16.04 and hasn't been tested for any other distribution.

An example playbook could look like this:

---
- hosts: all
  become: yes
  roles:
    - ROCK5GmbH.mailserver
  vars:
    - vault.yml

To get this role and all its dependencies, you can use the ansible galaxy:

ansible-galaxy install ROCK5GmbH.mailserver

To deploy on a single host, it is sufficient to execute

ansible-playbook --ask-vault-pass -i $HOST, playbook.yml

where $HOST is the IP address or URL of the server.

If you want to deploy to multiple hosts, it is recommended to work with inventories, so you can set variables per host while keeping common variables.

After the deployment, the mail server will be almost ready to go. All that's left now is to add actual domains and users to your SQL database. First use doveadm pw -s SHA512-CRYPT to generate a hash for the password for the user. To add the user, log in to your server then connect to the database via

mysql -u root -p

and enter the root password for the SQL database. Now add a domain (here: mysystems.tld) and a user (user1):

use vmail;
insert into domains (domain) values ('mysystems.tld');
insert into accounts (username, domain, password, quota, enabled, sendonly) values ('user1', 'mysystems.tld', '{SHA512-CRYPT}$kgid87hdenss', 2048, true, false);

Further customization

This setup also allows for TLS policies in the SQL database, allowing you to set specific TLS policies for specific domains. You can add a policy via

insert into tlspolicies (domain, policy, params) values ('gmx.de', 'secure', 'match=.gmx.net');

The different possible policies are listed and explained here. (The match=.gmx.net makes sure that postfix will check the certificate for gmx.net, since they do not have one for gmx.de)

You may also want to add your new mail server to your DNS (A(AAA) and MX record), as well as add an entry for SPF and DKIM.