Ansible

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Revision as of 08:18, 7 August 2013 by Fab (talk | contribs) (cat removed)
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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 client boxes is required.

Installation of ansible

ansible is available in testing. The latest package is broken, sorry.

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.

ssh-keygen -t rsa

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 authorized_keys file of the management system and Python.

Install the Python package.

apk add python

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.

ssh root@[IP of the management system] 'cat ~/.ssh/id_rsa.pub' | cat - >> ~/.ssh/authorized_keys

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

ssh-copy-id -i ~/.ssh/id_rsa.pub root@[IP of the management system]

Setup hosts

Add all your remote systems to /etc/ansible/hosts. For details, please refer to Hosts and Groups in the ansible documentation.

Contents of /etc/ansible/hosts

192.168.1.50 10.0.0.12 webserver.example.org mail.example.org

First test

$ ansible all -m ping -u you --sudo

Another test is check all variables.

# ansible [IP of your Alpine Linux box] -m setup

Playbooks

When writing playbooks for Alpine Linux there are some issues:

  1. There is basic support for APK by Ansible. But the following will always work

    action: command /sbin/apk add lighttpd

  2. Same with the OpenRC, the Init System

    action: command /etc/init.d/lighttpd start

  3. If you are going to re-use playbooks from other Linux distribution, please keep in mind that Alpine Linux uses different paths for the binaries. /bin/rm

The alpine-ansible git repository contain some example playbooks.