Ansible

Ansible is an ideal tool to efficiently configure and manage a network of computers. See how I use ansible to manage a fleet of Raspberry PIs and their build servers.

Ansible is a very powerful yet simple, in all its complexity. It is a wonderful tool that I get frequent use of. It’s real home I suppose is in the larger corporation devops world, it is wonderfully well suited to a mid sized IoT environment.

A Few Highlight about Ansible

Scripts are Accurate and Repeatable

Create Playbooks that combine a series of specific roles to get define specific roles the configuration steps to get a desired outcome. Once you figure out how to get something installed correctly, just script it out.

If and when things change and the script breaks, fix it, simple.

We have just ensured we can repeat the same successful installation over and over again, in record breaking time!

Processes Get Documented

By virtue of creating accurate names and descriptions of the tasks required for ansible, it will provide some great documentation of the actions performed by the varies roles.

How Ansible Works

Ansible runs playbooks from any host you care to run it from: we’ll call it the: “ansible host”. The ansible host can then over see the configuration management of any number of target hosts, we’ll call them “targets”.

At any given time ansible can be used to launch a single command or more typically a playbook that will invoke a series of actions to ensure all targets are configured and operating in the state specified by a series of roles that make up the ansible playbook.

Ansible playbooks can (and often are) run from: a laptop by a developer during test builds, or large enterprise servers that entrusted with maintainnig order and consistency in large complex enterprise arrangements.

Heck, Ansible can even be run from a Raspberry Pi! I think it provides some really powerful, and useful solutions to IoT problems.

Getting Started with Ansible

Running ansible at all requires the ansible host to be able to remotely login and control the targets. This must be established before ansible can do anything else.

Prepare your ansible targets with public ssh keys!

The key to getting started with ansible is to prepare all target hosts with the appropriate public SSH key(s) providing the ansible host with controlling access. This is the best, easiest and recommended way to get started.

Preload Targets with Keys

For physical servers (bare metal) this may require some manual preparation to load each target with the appropriate ssh key. May seem like a pain, but it is really trivial compared to the amount of work you will save allowing ansible to do the work.

Ansible provides other ways to access and control the targets, but when possible ssh keys are the best way to go.

In cases of Virtual Machines (VM) and Containers (containers) the necessary public keys maybe (depending on the virtual provider) preloaded when the new VM or container is spun up or provisioned. This is ideal, allowing us to create 100% zero touch provisioning!

anyway, back to ansible…