Ansible role to install and maintain the Bind9 nameserver on Debian

This role installs and configures the Bind9 nameserver on Debian.

Features:

• Support for configuring an authoritative nameserver for DNS zones and/or a DNS recursor
• Extensive DNSSEC support:
  • automatic KSK and ZSK key creation
  • automatic zone DNSSEC configuration
  • support to send DNSKEY/DS formatted output over XMPP
• Support for hidden primary and authoritative secondary configuration
• Support for so called "static" zones, i.e. zones defined uploading their raw .db bind file
• Validity check of zone files with named-checkzone
• Basic support for so called "dynamic" zones, i.e. defined from variables yaml variables sets

Basic server configuration

Master server

• set vars for your master server, for instance in host_vars/master_name/vars/XX_bind.yml, here with an example.com static zones and forwarder:

bind9_authoritative: yes
bind9_zones_static: 
- { name: example.com , type=master }
bind9_forward: yes
bind9_forward_servers:
- 8.8.8.8
- 4.4.4.4
bind9_slaves:
- slave_ip_1
- slave_ip_2
- slave_ip_3
bind9_our_neighbors:
- slave_ip_1
- slave_ip_2
- slave_ip_3

• Place your BIND zone file in ansible directory (not in role directory): `files/bind/zones/db.example.com

Slave servers

• set vars for your slave servers:

bind9_zones_static: 
- { name: example.com, type: slave }
bind9_forward: yes
bind9_forward_servers:
- 8.8.8.8
- 4.4.4.4
bind9_masters:
- { name: master_name, addresses: [master_ip] }
bind9_recursor: our_network

Dynamic zones

So called "dynamic" zones' records are defined through YAML ansible variable bind9_zones_dynamic which is parsed by bind/zones/db.template.j2 template. As there can be several zones, and zone definitions can be long, zone vars are worthily defined in a different vars file, for instance host_vars/master_name/vars/YY_zones.yml. bind9_zones_dynamic can be split in several variables, which can be defined in specific files, as in the example below.

In YY_zones.yml we may have:

bind9_zones_dynamic: >
        {{ zones_my_domains
        | union ( zone_my_reverse_inaddr_arpa )
        | union ( zone_my_reverse_ip6_arpa ) }}

# bind9_zone_static:  zone files copied from `files/bind/zones/`

bind9_zones_static:
- name: static_dom.org
  type: master
- name: static_dom2.org
  type: master
- name: static_dom3.org
  type: slave

And in other vars files:

zones_my_domains:
# This is the variables set for my domain
- name: dyn_domain.org
  type: master
  default_ttl: 600
  serial: 2022050501
  refresh: 1D
  retry: 2H
  expire: 1000H
  # NS and other pre-formatted records values must be given as full qualified domain names, with or without final dot, but not relative to the zone
  primary: ns1.dyn_domain.org         # Optional, if you don't define it, firs NS is taken 
  admin: postmaster.dyn_domain.org
  ns_records:
  - ns1.dyn_domain.org
  - ns2.dyn_domain.org
  # RR values are either relative to the zone, either with a final dot when outside.
  rrs:
  - {label: "@", type: MX, rdata: 10 mail}
  - {label: webmail, type: CNAME, rdata: mail}
  - {label: "@", type: A, rdata: 8.8.8.221}
  - {label: "@", type: AAAA, rdata: 2001:db8:6a::95}
  - {label: www, type: CNAME, rdata: webserver.dyn_domain.org.}
  - {label: mail, type: A, rdata: 8.8.8.222}
  - {label: mail, type: AAAA, rdata: 2001:db8:6a::22}
  - {label: webserver, ttl: 86400, type: A, rdata: 8.8.8.223}
  - {label: webserver, ttl: 86400, type: AAAA, rdata: 2001:db8:6a::23}

And similarly zone_my_reverse_inaddr_arpa and zone_my_reverse_ip6_arpa for IP reverse DNS resolution. Note that we adopted for generic NS records the terminology defined in RFC 1034, Section 3.6

• deploy role to your servers

DDNS updates

Key generation

If you want to have your DDNS keys created by this role configure bind9_generate_ddns_key:

-  bind9_generate_ddns_key: true

Keys will by default be stored to files/bind/zones withinin your playbook location, but you can customize this with bind9_local_keydir

-  bind9_local_keydir: credentials/bind

Zone database

Please note that for DDNS updates to work, the location of the zone files needs to be writable by the BIND process. Linux distros with Mandatory Access Control (Apparmor, SELinux) ususally don't allow writing to the default /etc/bind/zones path. In order to circumvent this you may want to change the zone files location to /var/lib/bind/zones instead:

-  bind9_zonedir: /var/lib/bind/zones

Dependencies

For the XMPP notification feature, python-xmpp needs to be installed.

Role varibles

See defaults/main.yml for a list of role variables.

Testing & Development

Tests

For developing and testing the role we use Github Actions, Molecule and Vagrant. On the local environment you can easily test the role with

Run local tests with:

molecule test 

License

This Ansible role is licensed under the GNU GPLv3.

Author

Copyright 2017-2020 systemli.org (https://www.systemli.org/)