An Ansible role for setting up ISC BIND as an authoritative-only DNS server for multiple domains. Specifically, the responsibilities of this role are to:
- install BIND
- set up the main configuration file (primary/secondary/forwarder server)
- set up forward and reverse lookup zone files
This role supports multiple forward and reverse zones, including for IPv6. Although enabling recursion is supported (albeit strongly discouraged), consider using another role if you want to set up a caching or forwarding name server.
If you like/use this role, please consider giving it a star and rating it on the role's Ansible Galaxy page. Thanks!
See the change log for notable changes between versions.
WARNING: If you've been using this role since before v5.0.0, please check the change log for important information on breaking changes. Old playbooks will fail if you upgrade to v5.0.0.
This role can be used on several platforms, see meta/main.yml for an updated list. We strive to set up automated tests for each supported platform (see .ci.yml), but this is not always possible.
A few remarks on supported roles that are not included in automated tests
- Arch Linux and FreeBSD should work, but at this time, it's not possible to test the role on these distros, since no suitable Docker images are available.
- CentOS 6 should work, but idempotence tests fail even if BIND is installed successfully and acceptance tests succeed.
The packages python-netaddr
(required for the ipaddr
filter) and dnspython
should be installed on the management node
Variable | Default | Comments (type) |
---|---|---|
bind_acls |
[] |
A list of ACL definitions, which are mappings with keys name: and match_list: . See below for an example. |
bind_allow_query |
['localhost'] |
A list of hosts that are allowed to query this DNS server. Set to ['any'] to allow all hosts |
bind_allow_recursion |
['any'] |
Similar to bind_allow_query , this option applies to recursive queries. |
bind_check_names |
[] |
Check host names for compliance with RFC 952 and RFC 1123 and take the defined action (e.g. warn , ignore , fail ). |
bind_dns_keys |
[] |
A list of binding keys, which are mappings with keys name: algorithm: and secret: . See below for an example. |
bind_dns64 |
false |
If true , support for DNS64 is enabled |
bind_dns64_clients |
['any'] |
A list of clients which the DNS64 function applies to (can be any ACL) |
bind_dnssec_enable |
true |
If true , DNSSEC is enabled |
bind_dnssec_validation |
true |
If true , DNSSEC validation is enabled |
bind_extra_include_files |
[] |
A list of custom config files to be included from the main config file |
bind_forward_only |
false |
If true , BIND is set up as a caching name server |
bind_forwarders |
[] |
A list of name servers to forward DNS requests to. |
bind_listen_ipv4 |
['127.0.0.1'] |
A list of the IPv4 address of the network interface(s) to listen on. Set to ['any'] to listen on all interfaces. |
bind_listen_ipv4_port |
[53] |
A list of port numbers to listen on for IPv4 addresses. |
bind_listen_ipv6 |
['::1'] |
A list of the IPv6 address of the network interface(s) to listen on |
bind_listen_ipv6_port |
[53] |
A list of port numbers to listen on for IPv6 addresses. |
bind_log |
data/named.run |
Path to the log file |
bind_other_logs |
- | A list of logging channels to configure, with a separate mapping for each zone, with relevant details |
bind_query_log |
- | A mapping with keyss file: (e.g. data/query.log ), versions: , size: . When defined, this will enable the query log |
bind_recursion |
false |
Determines whether requests for which the DNS server is not authoritative should be forwarded†. |
bind_rrset_order |
random |
Defines order for DNS round robin (either random or cyclic ) |
bind_statistics_channels |
false |
If true , BIND is configured with a statistics-channels clause (currently only supports listening on a single interface) |
bind_statistics_allow |
['127.0.0.1'] |
A list of hosts that can access the server statistics |
bind_statistics_host |
127.0.0.1 |
IP address of the network interface that the statistics service should listen on |
bind_statistics_port |
8053 | Network port that the statistics service should listen on |
bind_transfer_key_name |
- | The name of a TSIG key that should be used to sign XFR requests from the client |
bind_zone_dir |
- | When defined, sets a custom absolute path to the server directory (for zone files, etc.) instead of the default. |
bind_zones |
n/a | A list of mappings with zone definitions. See below this table for examples |
- allow_update |
['none'] |
A list of hosts that are allowed to dynamically update this DNS zone. |
- also_notify |
- | A list of servers that will receive a notification when the primary zone file is reloaded. |
- create_forward_zones |
- | When initialized and set to false , creation of forward zones will be skipped (resulting in a reverse only zone) |
- create_reverse_zones |
- | When initialized and set to false , creation of reverse zones will be skipped (resulting in a forward only zone) |
- delegate |
[] |
Zone delegation. |
- forwarders |
- | List of forwarders for for the forward type zone |
- hostmaster_email |
hostmaster |
The e-mail address of the system administrator for the zone |
- hosts |
[] |
Host definitions. |
- ipv6_networks |
[] |
A list of the IPv6 networks that are part of the domain, in CIDR notation (e.g. 2001:db8::/48) |
- mail_servers |
[] |
A list of mappings (with keys name: and preference: ) specifying the mail servers for this domain. |
- name_servers |
[ansible_hostname] |
A list of the DNS servers for this domain. |
- name |
example.com |
The domain name |
- naptr |
[] |
A list of mappings with keys name: , order: , pref: , flags: , service: , regex: and replacement: specifying NAPTR records. |
- networks |
['10.0.2'] |
A list of the networks that are part of the domain |
- other_name_servers |
[] |
A list of the DNS servers outside of this domain. |
- primaries |
- | A list of primary DNS servers for this zone. |
- services |
[] |
A list of services to be advertised by SRV records |
- text |
[] |
A list of mappings with keys name: and text: , specifying TXT records. text: can be a list or string. |
- type |
- | Optional zone type. If not specified, autodetection will be used. Possible values include primary , secondary or forward |
bind_zone_file_mode |
0640 | The file permissions for the main config file (named.conf) |
bind_zone_minimum_ttl |
1D |
Minimum TTL field in the SOA record. |
bind_zone_time_to_expire |
1W |
Time to expire field in the SOA record. |
bind_zone_time_to_refresh |
1D |
Time to refresh field in the SOA record. |
bind_zone_time_to_retry |
1H |
Time to retry field in the SOA record. |
bind_zone_ttl |
1W |
Time to Live field in the SOA record. |
† Best practice for an authoritative name server is to leave recursion turned off. However, for some cases it may be necessary to have recursion turned on.
In order to set up an authoritative name server that is available to clients, you should at least define the following variables:
Variable | Primary | Secondary | Forward |
---|---|---|---|
bind_allow_query |
V | V | V |
bind_listen_ipv4 |
V | V | V |
bind_zones |
V | V | V |
- hosts |
V | -- | -- |
- name_servers |
V | -- | -- |
- name |
V | V | -- |
- networks |
V | V | V |
- primaries |
V | V | -- |
- forwarders |
-- | -- | V |
bind_zones:
# Example of a primary zone (hosts: and name_servers: ares defined)
- name: mydomain.com # Domain name
create_reverse_zones: false # Skip creation of reverse zones
primaries:
- 192.0.2.1 # Primary server(s) for this zone
name_servers:
- pub01.mydomain.com.
- pub02.mydomain.com.
hosts:
- name: pub01
ip: 192.0.2.1
ipv6: 2001:db8::1
aliases:
- ns1
- name: pub02
ip: 192.0.2.2
ipv6: 2001:db8::2
aliases:
- ns2
- name: '@' # Enables "http://mydomain.com/"
ip:
- 192.0.2.3 # Multiple IP addresses for a single host
- 192.0.2.4 # results in DNS round robin
sshfp: # Secure shell fingerprint
- "3 1 1262006f9a45bb36b1aa14f45f354b694b77d7c3"
- "3 2 e5921564252fe10d2dbafeb243733ed8b1d165b8fa6d5a0e29198e5793f0623b"
ipv6:
- 2001:db8::2
- 2001:db8::3
aliases:
- www
- name: priv01 # This IP is in another subnet, will result in
ip: 10.0.0.1 # multiple reverse zones
- name: mydomain.net.
aliases:
- name: sub01
type: DNAME # Example of a DNAME alias record
networks:
- '192.0.2'
- '10'
- '172.16'
delegate:
- zone: foo
dns: 192.0.2.1
services:
- name: _ldap._tcp
weight: 100
port: 88
target: dc001
naptr: # Name Authority Pointer record, used for IP
- name: "sip" # telephony
order: 100
pref: 10
flags: "S"
service: "SIP+D2T"
regex: "!^.*$!sip:[email protected]!"
replacement: "_sip._tcp.example.com."
# Minimal example of a secondary zone
- name: acme.com
primaries:
- 172.17.0.2
networks:
- "172.17"
# Minimal example of a forward zone
- name: acme.com
forwarders:
- 172.17.0.2
networks:
- "172.17"
Host names that this DNS server should resolve can be specified in bind_zones.hosts
as a list of mappings with keys name:
, ip:
, aliases:
and sshfp:
. Aliases can be CNAME (default) or DNAME records.
To allow to surf to http://example.com/
, set the host name of your web server to '@'
(must be quoted!). In BIND syntax, @
indicates the domain name itself.
If you want to specify multiple IP addresses for a host, add entries to bind_zones.hosts
with the same name (e.g. priv01
in the code snippet). This results in multiple A/AAAA records for that host and allows DNS round robin, a simple load balancing technique. The order in which the IP addresses are returned can be configured with role variable bind_rrset_order
.
As you can see, not all hosts are in the same subnet. This role will generate suitable reverse lookup zones for each subnet. All subnets should be specified in bind_zones.networks
, though, or the host will not get a PTR record for reverse lookup.
Remark that only the network part should be specified here! When specifying a class B IP address (e.g. "172.16") in a variable file, it must be quoted. Otherwise, the Yaml parser will interpret it as a float.
Based on the idea and examples detailed at https://linuxmonk.ch/wordpress/index.php/2016/managing-dns-zones-with-ansible/ for the gdnsd package, the zone files are fully idempotent, and thus only get updated if "real" content changes.
Zone type
is an optional zone parameter that defines if the zone type should be of primary
, secondary
or forward
type. When type
parameter is omitted, zone type will be autodetected based on the intersection of host IP addresses and primaries
record when configuring primary or secondary zone. When primaries
is not defined and forwarders
is defined, the zone type will be set to forward
.
Zone auto-detection functionality is especially useful when deploying multi-site DNS infrastructure. It is convenient to have a "shared" bind_zones
definitions in a single group inventory file for all dns servers ( ex. group_vars\dns.yml
). Such an approach allows to switch between primary and secondary server(s) roles by updating primaries
record only and rerunning the playbook.
See example of shared bind_zones
in molecule/shared_inventory/converge.yml and the accompanying dns.yml file.
This scenario can be tested by running molecule test --scenario-name shared_inventory
NOTE
- bind doesn't support automated multi-master configuration and
primaries
list should have a single entry only. - When
primaries
record is updated to switch primary to secondary server roles, zones will be wiped out and recreated from template as we yet to support dynamic updates for existing zones.
Zone types can be also defined explicitly in per host inventory to skip autodetection:
# Primary Server
bind_zones:
- name: mydomain.com
type: primary
primaries:
- 192.0.2.1
...
# Secondary Server
bind_zones:
- name: mydomain.com
type: secondary
primaries:
- 192.0.2.1
...
# Forwarder Server
bind_zones:
- name: anotherdomain.com
type: forward
forwarders:
- 192.0.3.1
To delegate a zone to a DNS server, it is sufficient to create a NS
record (under delegate) which is the equivalent of:
foo IN NS 192.0.2.1
Service (SRV) records can be added with the services. This should be a list of mappings with mandatory keys name:
(service name), target:
(host providing the service), port:
(TCP/UDP port of the service) and optional keys priority:
(default = 0) and weight:
(default = 0).
ACLs can be defined like this:
bind_acls:
- name: acl1
match_list:
- 192.0.2.0/24
- 10.0.0.0/8
The names of the ACLs will be added to the allow-transfer
clause in global options.
Binding keys can be defined like this:
bind_dns_keys:
- name: primary_key
algorithm: hmac-sha256
secret: "azertyAZERTY123456"
bind_extra_include_files:
- "{{ bind_auth_file }}"
tip: Extra include file must be set as an ansible variable because file is OS dependant
This will be set in a file "{{ bind_auth_file }} (e.g. /etc/bind/auth_transfer.conf for Debian) which have to be added in the list variable bind_extra_include_files
Warning: this functionality is broken in v5.0.0
To authorize the transfer of zone between primary & secondary servers based on a TSIG key, set the name in the variable bind_transfer_key_name
:
bind_transfer_key_name: primary_key
A check will be performed to ensure the key is actually present in the bind_dns_keys
mapping. This will add a server statement for the a
in bind_auth_file
on a secondary server containing the specified key.
No dependencies.
See the test playbooks for an elaborate example that showcases most features.:
- Standard Inventory - converge.yml and the accompanying
group_vars/all.yml
file all.yml - Shared Inventory - converge.yml and the accompanying
group_vars/dns.yml
file all.yml
This role is tested using Ansible Molecule. Tests are launched automatically on Github Actions after each commit and PR.
This Molecule configuration will:
- Run Yamllint and Ansible Lint
- Create three Docker containers, one primary (
ns1
), one secondary (ns2
) DNS server and forwarder(ns3
) -default
molecule scenario - Run a syntax check
- Apply the role with a test playbook and check idempotence
- Run acceptance tests with verify playbook
- Create additional two Docker container, one primary(
ns4
) and one secondary (ns5
) and runshared_inventory
scenario
This process is repeated for all the supported Linux distributions.
In order to run the acceptance tests on this role locally, you can install the necessary tools on your machine, or use this reproducible setup in a VirtualBox VM (set up with Vagrant): https://github.com/bertvv/ansible-testenv.
Steps to install the tools manually:
- Docker should be installed on your machine
- As recommended by Molecule, create a python virtual environment
- Install the software tools
python3 -m pip install molecule molecule-docker docker netaddr dnspython yamllint ansible-lint
- Navigate to the root of the role directory and run
molecule test
Molecule automatically deletes the containers after a test. If you would like to check out the containers yourself, run molecule converge
followed by molecule login --host HOSTNAME
.
The Docker containers are based on images created by Jeff Geerling, specifically for Ansible testing (look for images named geerlingguy/docker-DISTRO-ansible
). You can use any of his images, but only the distributions mentioned in meta/main.yml are supported.
The default config will start two Centos 7 containers (the primary supported platform at this time). Choose another distro by setting the MOLECULE_DISTRO
variable with the command, e.g.:
MOLECULE_DISTRO=debian9 molecule test
or
MOLECULE_DISTRO=debian9 molecule converge
You can run the acceptance tests on both servers with molecule verify
.
NOTE
- Molecule verify tests will fail if docker is running on MacOS. This is a known issue. See #2670
BSD
This role could only have been realized thanks to the contributions of many. If you have an idea to improve it even further, don't hesitate to pitch in!
Issues, feature requests, ideas, suggestions, etc. can be posted in the Issues section.
Pull requests are also very welcome. Please create a topic branch for your proposed changes. If you don't, this will create conflicts in your fork after the merge. Don't hesitate to add yourself to the contributor list below in your PR!
Maintainers:
Contributors:
- Aido
- Angel Barrera
- B. Verschueren
- Boris Momčilović
- Brad Durrow
- Christopher Hicks
- David J. Haines
- Fabio Rocha
- Fazle Arefin
- Greg Cockburn
- Guillaume Darmont
- jadjay
- Jascha Sticher
- Joanna Delaporte
- Jörg Eichhorn
- Jose Taas
- Lennart Weller
- Loic Dachary
- Mario Ciccarelli
- Otto Sabart
- Paulius Mazeika
- Paulo E. Castro
- Peter Janes
- psa
- Rafael Bodill
- Rayford Johnson
- Robin Ophalvens
- Romuald
- Tom Meinlschmidt
- Jascha Sticher