Ansible Role: Exim4

Ansbile role to install and configure Exim4 on Debian or Ubuntu system.

With that role you may fine tune your Exim4 installation using variables.

Usage

Download a role onto your Ansible host using the ansible-galaxy command that comes bundled with Ansible.

$ ansible-galaxy install adegtyarev.exim4

Define a role in your playbook and setup desired options. For example:

roles:
  - role: adegtyarev.exim4

The defaults installs exim4-daemon-light package and no additional configuration is made except the defaults for the OS. This role follows Debian package concept of configuring Exim. See below how to enable or disable features in your setup.

Note that this role adds default Exim user Debian-exim into group ssl-cert to let the daemon to access SSL certificates and keys.

Role Variables

Variable	Default value	Description
exim4_package_name	exim4-daemon-light	Sets the package name to install
exim4_conf_keyvalue	empty	A lists of dictionaries of key-values (see below)
exim4_conf_values	empty	A lists of dictionaries with one-per-line values (see below)

For exim4_package_name value good choice is also exim4-daemon-heavy or any other name available for your system.

Using lists of dictionaries

exim4_conf_keyvalue used to create config files with key-value pairs of data. For example, to configure a list of route_data records which can be used to override or augment MX information from the DNS:

exim4_conf_keyvalue:
  - name: hubbed_hosts
    data:
      example.com: mail.example.com
      example.net: mail.example.net

As a result, file /etc/exim4/hubbed_hosts will be created with key-value pairs of domain pattern and route data.

exim4_conf_values used to create config files with flat list values. For example, to configure a list of envelope recipients for which incoming messages are subject to recipient verification with a callout:

exim4_conf_values:
  - name: local_rcpt_callout
    data:
      - "*@example.com"
      - "*@example.net"

As a result, file with address list /etc/exim4/local_rcpt_callout will be created.

For more info about files in use by the Debian exim4 package, please consult man exim4-config_files

Maintaining update-exim4.conf.conf

The following variables and their default values are used for the content of the /etc/exim4/update-exim4.conf.conf file:

Variable	Default value	Description
exim4_dc_eximconfig_configtype	internet	Mail server configuration type
exim4_dc_other_hostnames	ansible_hostname	Other destinations for which mail is accepted
exim4_dc_local_interfaces	127.0.0.1 ; ::1	IP-addresses to listen on
exim4_dc_minimaldns	false	Keep number of DNS-queries minimal
exim4_dc_localdelivery	mail_spool	Delivery method for local mail
exim4_dc_use_split_config	false	Split configuration into small files?
exim4_dc_mailname_in_oh	true	Internal use only
exim4_dc_relay_nets	empty	Machines to relay mail for
exim4_dc_relay_domains	empty	Domains to relay mail for
exim4_CFILEMODE	644	The octal file mode of the generated file

Smarthost-specific variables:

Variable	Default value	Description
exim4_dc_smarthost	empty	IP address or host name of the outgoing smarthost
exim4_dc_hide_mailname	empty	Hide local mail name in outgoing mail?
exim4_dc_readhost	empty	Visible domain name for local users

For more info about the meaning of these configuration variables please consult man page for update-exim4.conf.

The following variables are used in default template to configure Exim4:

• exim4_custom_options
• exim4_passwd_client: Account and password data for SMTP authentication when exim is authenticating as a client to some remote server as a list.

The following features are built into this role:

• 00_exim4-config_tls: Enable TLS in Exim
• 02_exim4-custom_options: Custom options to add into config ...

Configure DKIM in Exim4

Configure Exim to sign outgoing messages with DKIM is as easy as:

exim4_dkim_enable: true

exim4_features_enable:
    - name: 30_exim4-config_dkim
      group: main

To re-configure existing Exim installation, add this variables to appropriate group- or host- vars and then run Ansible with exim4-dkim,exim4-reconfigure tags:

ansible-playbook -t exim4-dkim,exim4-reconfigure playbook.yml

This will generate a public/private key which will be used for signing and validation. You will need to publish the resulting public key using a TXT record:

dkim._domainkey.example.com IN TXT "k=rsa; p={{PUBLIC_KEY}}"

Where {{PUBLIC_KEY}} is content of /etc/exim4/dkim.public with removed first and last lines, and line breaks removed as well.

The following variables and their default values are used:

Variable	Default value	Description
exim4_dkim_keysize	2048	Key size
exim4_dkim_canon	relaxed	Canonicalization method used when signing a message
exim4_dkim_selector	dkim	Key selector string

You may want to adjust them to best suite your setup.

Maintaining Exim4 log rotation

By default this role keep log rotation settings as it is set in a Debian package. To adjust these settings the following variables are used:

exim4_logrotate_base:
  - name: exim4-base
    path: /var/log/exim4/mainlog /var/log/exim4/rejectlog
    type: daily
    rotate: 10
    create: 640 Debian-exim adm

exim4_logrotate_paniclog:
  - name: exim4-paniclog
    path: /var/log/exim4/paniclog
    type: size 10M
    rotate: 10
    create: 640 Debian-exim adm

This example setup rotation of mainlog and rejectlog on a monthly basis:

exim4_logrotate_base:
  - name: exim4-base
    path: /var/log/exim4/mainlog /var/log/exim4/rejectlog
    type: monthly

Enable of disable features in Exim4

Enable or disable Exim4 features for your setup. For example:

exim4_features_enable:
  - name: 02_exim4-custom_options
    group: main

  - name: 30_exim4-config_dovecot_lmtp
    group: transport

exim4_features_disable:
  - name: 30_exim4-config_examples
    group: auth

exim4_custom_options:
  - daemon_smtp_ports: "25 : 465 : 587"
  - rfc1413_query_timeout: 0s
  - smtp_banner: "ESMTP server ready $tod_full"

This will enable builtin features:

• 02_exim4-custom_options in config group main
• 30_exim4-config_dovecot_lmtp in config group transport

And disable 30_exim4-config_examples feature if exist in /etc/exim/conf.d/auth.

Feature 02_exim4-custom_options adds custom options provided in exim4_custom_options into Exim4 config.

The following tags may be used to re-configure Exim4:

• exim4: runs all tasks in role unless explicitly disabled
• exim4-reconfigure: run re-confguration to apply updated parameters (if any)
• exim4-reconfigure-logrotate: re-configure log rotation

License

BSD

Author Information

• Alexey Degtyarev alexey@renatasystems.org