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[https://www.ansible.com/ Ansible] is a simple configuration management, deployment, task-execution, and multinode orchestration framework.

It uses SSH for the communication between the involved systems, no server or client daemons are needed, and no additional software beside Python on managed nodes is required.

== Installation ==

On the control node (master host), you can install the {{Pkg|ansible-core}} package and/or the {{Pkg|ansible}} package, which is a "batteries included" package that brings in {{Pkg|ansible-core}} along with a set of curated [https://docs.ansible.com/collections.html collections].  Both are available from the [[Repositories#Community|community]] repository:

{{Tip|If you don't know you need {{Pkg|ansible-core}}, I would recommend installing {{Pkg|ansible}}.}}

{{Cmd|# apk add ansible}}

=== Create a SSH key ===

Generate a SSH key for the managed node. It's recommended to use a key which is protected with a password.

{{Cmd|$ ssh-keygen -t ed25519}}

== Managed nodes ==

There are only minimal requirements for the clients. For every system you want to manage, you need to have the client's SSH key in the <code>authorized_keys</code> file of the management system and Python.

Install the Python package:

{{Cmd|# apk add python3}}

=== Transfer the SSH key ===
There are two ways to do it. From a default Alpine installation you can use ssh and cat to do it.

{{Cmd|<nowiki>ssh root@[IP of the management system] 'cat ~/.ssh/id_ed25519.pub' | cat - >> ~/.ssh/authorized_keys</nowiki>}}

If you are planning to use additional features of SSH. <code>ssh-copy-id</code>, which is provided by the <code>openssh-client</code> package, can help you with the key setup. 

{{Cmd|ssh-copy-id -i ~/.ssh/id_ed25519.pub root@[IP of the management system]}}

== Usage ==

=== Configuration ===

{{Todo|https://docs.ansible.com/ansible/latest/reference_appendices/config.html}}

=== Inventory ===

The inventory is the list of managed nodes or "hosts".  The default location is <code>/etc/ansible/hosts</code>.  You can specify a different inventory file using <code>-i PATH</code> on the command line.
See [https://docs.ansible.com/ansible/latest/inventory_guide/intro_inventory.html How to build your inventory] for more information.

{{Cat|/etc/ansible/hosts|[control]
10.0.0.5

[managed]
10.0.1.5
10.0.1.50}}

=== Ping ===

Check that you can reach all nodes:

{{Cmd|$ ansible all -m ping}}

=== Playbooks ===
When writing playbooks for Alpine Linux there are some things to keep in mind:

<ol>
<li>There is support for OpenRC, the [[OpenRC|Init System]], in the [https://docs.ansible.com/ansible/latest/collections/ansible/builtin/service_module.html service] module.
<pre>
- name: Make "lighttpd" start on boot and start now, if not started.
  ansible.builtin.service:
    name: lighttpd
    enabled: true
    state: started
</pre>
<li>There is support for [[Alpine_Package_Keeper|APK]] as of Ansible 2.0, in the [https://docs.ansible.com/ansible/latest/collections/community/general/apk_module.html apk] module.
<pre>
- name: Ensure lighttpd is installed, update cache and install if not.
  community.general.apk:
    name: lighttpd
    state: present
    update_cache: yes
</pre>
<li>There is support for the [[Alpine_Wall|Awall]] firewall as of Ansible 2.4, in the [https://docs.ansible.com/ansible/latest/collections/community/general/awall_module.html awall] module.
<pre>
- name: Enable "foobar" policy
  community.general.awall:
    name: foobar
    state: enabled
    activate: true
</pre>
<li>
If you are going to re-use playbooks from other Linux distributions, please keep in mind that Alpine Linux uses different paths for the binaries.  For example <code>rm</code> is <code>/bin/rm</code>.
</ol>

=== Vault ===

{{Todo|https://docs.ansible.com/ansible/latest/vault_guide/index.html}}

=== ansible-lint ===

You can check if you're using "[https://ansible-lint.readthedocs.io/ proven practices]",
by installing the {{Pkg|ansible-lint}} package and running:

{{Cmd|$ ansible-lint -s ./PATH}}

== See Also ==

* https://docs.ansible.com/ansible/latest/collections/community/general/apk_module.html - Official documentation for the apk module.
* [https://wiki.archlinux.org/title/Ansible ArchWiki: Ansible]

[[Category:Installation]]
[[Category:System_Administration]]