Ansible Role: PowerDNS Recursor

An Ansible role created by the folks behind PowerDNS to setup the PowerDNS Recursor.

Requirements

An Ansible 2.12 or higher installation.

Dependencies

None.

Role Variables

Available variables are listed below, along with default values (see defaults/main.yml):

pdns_rec_install_repo: ""

By default, the PowerDNS Recursor is installed from the software repositories configured on the target hosts.

# Install the PowerDNS Recursor from the 'master' official repository
- hosts: pdns-recursors
  roles:
  - { role: PowerDNS.pdns_recursor,
      pdns_rec_install_repo: "{{ pdns_rec_powerdns_repo_master }}" }

# Install the PowerDNS Recursor from the '5.0.x' official repository
- hosts: pdns-recursors
  roles:
  - { role: PowerDNS.pdns_recursor,
      pdns_rec_install_repo: "{{ pdns_rec_powerdns_repo_50 }}" }

# Install the PowerDNS Recursor from the '5.1.x' official repository
- hosts: pdns-recursors
  roles:
  - { role: PowerDNS.pdns_recursor,
      pdns_rec_install_repo: "{{ pdns_rec_powerdns_repo_51 }}" }

# Install the PowerDNS Recursor from the '5.2.x' official repository
- hosts: pdns-recursors
  roles:
  - { role: PowerDNS.pdns_recursor,
      pdns_rec_install_repo: "{{ pdns_rec_powerdns_repo_52 }}" }

The examples above, show how to install the PowerDNS Recursor from the official PowerDNS repositories (see the complete list of pre-defined repos in vars/main.yml).

The roles also supports custom repositories

- hosts: all
  vars:
    pdns_rec_install_repo:
      name: "powerdns-rec"  # the name of the repository
      apt_repo_origin: "repo.example.com"   # used to pin the PowerDNS packages to the provided repository
      apt_repo: "deb http://repo.example.com/{{ ansible_distribution | lower }} {{ ansible_distribution_release | lower }}/pdns-recursor main"
      gpg_key: "http://repo.example.com/MYREPOGPGPUBKEY.asc" # repository public GPG key
      gpg_key_id: "MYREPOGPGPUBKEYID" # to avoid to reimport the key each time the role is executed
      yum_repo_baseurl: "http://repo.example.com/centos/$basearch/$releasever/pdns-recursor"
      yum_repo_debug_symbols_baseurl: "http://repo.example.com/centos/$basearch/$releasever/pdns-recursor/debug"
  roles:
  - { role: PowerDNS.pdns_recursor }

It is also possible to install the PowerDNS Recursor from custom repositories as demonstrated in the example above.

pdns_rec_install_epel: True

By default, install EPEL to satisfy some PowerDNS Recursor dependencies like protobuf. To skip the installation of EPEL set pdns_rec_install_epel to False.

pdns_rec_package_name: "{{ default_pdns_rec_package_name }}"

The name of the PowerDNS Recursor package, pdns-recursor on RedHat-like Debian-like systems.

pdns_rec_package_version: ""

Optionally, allow to set a specific version of the PowerDNS Recursor package to be installed.

pdns_rec_install_debug_symbols_package: False

Install the PowerDNS Recursor debug symbols.

pdns_rec_debug_symbols_package_name: "{{ default_pdns_rec_debug_symbols_package_name }}"

The name of the PowerDNS Recursor debug package to be installed when pdns_install_debug_symbols_package is True, pdns-recursor-debuginfo on RedHat-like systems and pdns-recursor-dbg on Debian-like systems.

pdns_rec_user: "{{ default_pdns_rec_user }}"
pdns_rec_group: "{{ default_pdns_rec_group }}"

The user and group the PowerDNS Recursor will run as, pdns-recursor on RedHat-like systems and pdns on Debian-like systems
NOTE: This role does not create any user or group as we assume that they're created by the package or other roles.

pdns_rec_file_owner: "root"
pdns_rec_file_group: "{{ default_pdns_file_group }}"

User and group owning the configuration files and directories.

pdns_rec_service_name: "pdns-recursor"

The name of the PowerDNS Recursor service.

pdns_rec_service_state: "started"
pdns_rec_service_enabled: "yes"

Allow to specify the desired state of the PowerDNS Recursor service. E.g. This allows to install and configure the PowerDNS Recursor without automatically starting the service.

pdns_rec_disable_handlers: False

Disable automated service restart on configuration changes.

pdns_rec_config_dir: "{{ default_pdns_rec_config_dir }}"
pdns_rec_config_file: "recursor.conf"

The PowerDNS Recursor configuration files and directories, where default_pdns_rec_config_dir is /etc/powerdns on Debian and /etc/pdns-recursor on RedHat.

pdns_rec_custom_config: { }

Dictionary containing in YAML format the custom configuration of PowerDNS Recursor. NOTE: You should not set the config-dir, lua_config_file,lua_dns_script, set-uid and set-gid because are set by other role variables (respectively pdns_rec_config_dir, pdns_rec_user, pdns_rec_group).

pdns_res_config_lua: "{{ pdns_rec_config_dir }}/config.lua"
pdns_rec_config_lua_file_content: ""

If pdns_rec_config_lua_file_content is not "", this will dump the content of this variable to the pdns_res_config_lua file and define accordingly the lua-config-file setting in the recursor.conf configuration file.

pdns_rec_config_dns_script: "{{ pdns_rec_config_dir }}/dns-script.lua"
pdns_rec_config_dns_script_file_content: ""

If pdns_rec_config_dns_script_file_content is not "", this will dump the content of this variable to the pdns_rec_config_dns_script file and define accordingly the lua-dns-script setting in the recursor.conf configuration file.

pdns_rec_service_overrides:
  User: "{{ pdns_rec_user }}"
  Group: "{{ pdns_rec_group }}"

Dict with overrides for the service (systemd only). This can be used to change any systemd settings in the [Service] category

pdns_rec_config_from_files_dir_mode: 0750
pdns_rec_config_from_files: []
#pdns_rec_config_from_files:
#  - dest: "/var/lib/pdns-recursor/from-files/forward-zones.txt"
#    src: "files/forward-zones/forward.txt"

List of files to copy to the PowerDNS Recursor instance, could be used for the *-from-file settings in the recursor.conf configuration file. The variable pdns_rec_config_from_files_dir_mode allows to change the ownership mode of files, if required.

pdns_rec_config_include_dir_mode: 0750

The pdns_rec_config_include_dir_mode will change the mode of directories form include-dir settings, in case one of them required some writing permissions.

Example Playbooks

Bind to 203.0.113.53 on port 5300 and allow only traffic from the 198.51.100.0/24 subnet:

- hosts: pdns-recursors
  vars:
    pdns_rec_config:
      allow-from: "198.51.100.0/24"
      local-address: "203.0.113.53:5300"
  roles:
    - { role: PowerDNS.pdns_recursor }

Allow traffic from multiple networks and set some custom ulimits overriding the default systemd service:

- hosts: pdns-recursors
  vars:
    pdns_rec_config:
      allow-from:
        - "198.51.100.0/24"
        - "203.0.113.53/24"
      local-address: "203.0.113.53:5300"
    pdns_rec_service_overrides:
      LimitNOFILE: 10000
  roles:
    - { role: PowerDNS.pdns_recursor }

Allow traffic from multiple networks and set some custom ulimits overriding the default systemd service, but keeping in the default overrides from this role. This is recommended when using PowerDNS 4.3 and up.

- hosts: pdns-recursors
  vars:
    pdns_rec_config:
      allow-from:
        - "198.51.100.0/24"
        - "203.0.113.53/24"
      local-address: "203.0.113.53:5300"
    pdns_rec_service_overrides: '{{ default_pdns_rec_service_overrides | combine({"LimitNOFILE": 10000})'
  roles:
    - { role: PowerDNS.pdns_recursor }

Forward queries for corp.example.net to a nameserver on localhost and queries for foo.example to other nameservers:

- hosts: pdns-recursors
  vars:
    pdns_rec_config:
      forward-zones:
        - "corp.example.net=127.0.0.1:5300"
        - "foo.example=192.0.2.3;2001:db8::2:3"
  roles:
    - { role: PowerDNS.pdns_recursor }

Changelog

A detailed changelog of all the changes applied to the role is available here.

Testing

Tests are performed by Molecule.

$ pip install tox

To test all the scenarios run

$ tox

To run a custom molecule command

$ tox -e ansible216 -- molecule test -s pdns-rec-52

License

MIT