Ansible¶

Redbrick uses ansible to manage its infrastructure. This document describes the procedures and some tips to get the most out of it.

Getting Started¶

Installing Ansible¶

Ansible is a python package, so you'll need to install python first. On Debian/Ubuntu, you can do this with:

Bash

pip install ansible

Add an SSH Key¶

Ansible uses ssh to connect to the remote hosts. You'll need to set up your ssh key so that you can connect to the hosts without constant prompts for passwords.

Create a Hosts File¶

This is used a phonebook of sorts for ansible. It tells ansible which hosts to connect to, and what user to use.

INI

[aperture]
glados
wheatley
chell

[aperture:vars]
ansible_user= <your username>

Contact @distro for a fully populated file.

Test it out¶

Bash

ansible all -m ping

This should connect to all the hosts in the aperture group, and run the ping module. If it works, you're good to go!

Playbooks¶

Ansible playbooks are a set of instructions for ansible to run. They're written in YAML, and are usually stored in a file called playbook.yml.

Writing a Playbook¶

Ansible playbooks are written in YAML. The basic structure is:

YAML

- hosts: <group name>
  tasks:
    - name: <task name>
      <module name>:
        <module options>

Example¶

YAML

- hosts: aperture
  tasks:
    - name: Install curl
      apt:
        name: curl
        state: present

This playbook will connect to all the hosts in the aperture group, and run the apt module with the name and state options.

Running a Playbook¶

Bash

ansible-playbook playbook.yml -i hosts

More Information¶

Redbrick's ansible configuration is stored in the ansible folder in the redbrick/nomad repository. There's some more documentation there on each playbook.

Ansible's documentation is available here.

Common Errors¶

Hashicorp Apt Key¶

Sometimes, when running a playbook, you'll get an error like this:

Bash

TASK [apt : apt update packages to their latest version and autoclean] ***************************************************************************************************
fatal: [wheatley]: FAILED! => {"changed": false, "msg": "Failed to update apt cache: unknown reason"}
fatal: [chell]: FAILED! => {"changed": false, "msg": "Failed to update apt cache: unknown reason"}
fatal: [glados]: FAILED! => {"changed": false, "msg": "Failed to update apt cache: unknown reason"}

This is because the Hashicorp apt key has expired. To fix this, uncomment the hashicorp-apt task in the playbook.