ansible/rst/index.rst

Introducing Ansible

Ansible is a radically simple model-driven configuration management, deployment, and command execution framework. Other tools in this space have been too complicated for too long, require too much bootstrapping, and have too much learning curve. By comparison, Ansible is dead simple and painless to extend. Puppet and Chef have about 60k lines of code. Ansible's core is a little over 2000 lines.

Ansible isn't just for configuration management -- it's also great for ad-hoc tasks, quickly firing off commands against nodes, and it excels at complex multi-tier deployment tasks, being designed for that purpose from day one.

Systems management doesn't have to be complicated. We've learned well from the "Infrastructure is Code" movement. Infrastructure should be easy and powerful to command, but it should not look like code, lest it acquire the disadvantages of a software project -- bugs, complexity, and overhead. Infrastructure configurations should be simple, easy to develop, and easy to audit. This is Ansible's philosophy and the main reason it's different. Read on, though, and we'll tell you more.

Key Features
Dead simple setup
Can be easily run from a checkout, no installation required
No agents or software to install on managed machines
Ultra-secure; uses existing SSHd out of the box
Connect as any user, not just root, and sudo as needed
Super fast & parallel by default
Supports Kerberized SSH, jump hosts, forwarding, etc
Modules are idempotent, but you can also easily use shell commands
Modules can be written in ANY language
Orchestrates load balancer rotations and outage windows
Awesome API for creating very powerful distributed applications
Pluggable transports (SSH is just the default)
Can draw inventory data from external sources like EC2 and Cobbler
The easiest config management system to use, ever.

Architecture

Tell Me More
Multi-node control & orchestration	Ansible is especially strong at expressing complex multi-node deployment processes, executing ordered sequences on different sets of nodes through playbooks. Performing steps on all your webservers, then some steps on your database servers, and then some steps on monitoring servers -- all the while sharing variables between them is trivial.
Doesn't choose sides in the language war	Modules can be written in Bash, Perl, Python, Ruby, whatever. Playbooks are not a programming language, but a data format.
Infrastructure Is Not Code, Infrastructure Is Data	Playbooks are not a programming language, they are designed to be super-easy to write, and easy to audit by non-developers. You will be able to skim and very quickly understand your entire configuration policy.
Three In One	Ansible handles multiple command and control problems in one tool. You don't need to use a config tool, a deployment tool, and yet another ad-hoc parallel task execution tool -- Ansible will do all three.
Lower Attack Surface, No Agents	Ansible is very secure. Ansible uses SSH as a transport, resulting in a much lower attack surface, and requires no agents to be running on managed machines. If a central server containing your playbooks are comprimised, your nodes are not --which is NOT the case of most other tools, which can, more or less, turn into a botnet. Our security approach is to avoid writing custom crypto code altogether, and rely on the most secure part of the Linux/Unix subsystem that your machines are already using -- openssh.

Community
Your ideas and contributions are welcome. We're also happy to help you with questions about Ansible.
Get the source	Visit the project page on Github
File a bug	View the issue tracker
Spread the word	Watch slides on Speakerdeck
Join the mailing list	Visit the Google Group
Chat	Visit the channel on FreeNode
Share & Learn	Share playbooks, modules, articles, and scripts

What (Real) People Are Saying
"I've been trying to grok Chef these last weeks, and really, I don't get it. I discovered ansible yesterday at noon, successfully ran it at 1pm, made my first playbook by 2pm, and pushed two small [contributions to the project] before the office closed... Do that with any other config management software!"
"Ansible is much more firewall-friendly. I have a number of hosts that are only accessible via reverse SSH tunnels, and let me tell you getting puppet or chef to play nice with that is a nightmare."
"This software has really changed my life as an network admin, the simplicity ansible comes with is really childs-play and I really adore its design. No more hassle with SSL keys, DNS based 'server entries' (e.g. puppet and what not). Just plain (secure!) SSH keys and one is good to go."
"You may get a kick out of the fact that I'm using ansible to install puppetmaster(s). I'm starting to migrate all my stuff to the much more sensical ansible. Nice work."
"Simple as hell"
"I swear, I have gotten more done with Ansible in three days than I did in not getting chef installed in three weeks."
"Puppet was hell... gave up on Chef... found ansible and couldn't be happier."
"Really impressed with Ansible. Up and running in ¼ of the time it took to get going with Puppet."

Presented By...

Ansible was created and is run by Michael DeHaan (@laserllama), a Raleigh, NC based software developer and architect, who also created the popular open-source DevOps install server Cobbler. Cobbler is used to deploy mission critical systems all over the planet, in industries ranging from massively multiplayer gaming, core internet infrastructure, finance, chip design, and more. Michael also helped co-author Func, a precursor to Ansible, which is used to orchestrate systems in lots of diverse places. He's worked on systems software for IBM, Motorola, Red Hat's Emerging Technologies Group, Puppet Labs, and is now with rPath. Reach Michael by email here.

Documentation

gettingstarted patterns examples modules YAMLSyntax playbooks playbooks2 bestpractices api moduledev faq who_uses_ansible