batou
=====
.. rubric:: automating web application deployments
.. raw:: html
Release v\ |version|.
batou is a BSD licensed utility, written in Python, to configure
development and production environments for web applications.
Deployments are hard and complicated. Tools like Docker, Puppet, chef, and
others exist that try to solve this problem once and for all. However, they
usually need you to change your workflow or toolchain massively while still
missing important steps.
batou makes deployments more bearable without requiring developers to change
their applications. It provides a "one command" approach that should never
need additional wrapper scripts.
As a developer all you ever have to run after cloning or updating your project
is:
.. code-block:: console
$ hg clone https://bitbucket.org/example/myproject
$ cd myproject
$ ./batou deploy dev
To run a production deployment all you should ever have to run is:
.. code-block:: console
$ cd my-project
$ git pull
$ ./batou deploy prod
Writing a deployment with batou is a two step process:
Step 1: Model your application's configuration
----------------------------------------------
With our component model you write a configuration specification in Python
based on a simple API. Components make configuration `convergent `_ and `idempotent `_
and using Python lets you perform any computation you need. The component
model is recursive, so you can refactor complicated components into simpler
ones without breaking your setup.
Here is an example application model that installs a Python package into a
VirtualEnv and asks Supervisor to run it:
.. code-block:: python
from batou.component import Component
from batou.lib.python import VirtualEnv, Package
from batou.lib.supervisor import Program
class MyApp(Component):
def configure(self):
venv = VirtualEnv('2.7')
self += venv
venv += Package('myapp')
self += Program('myapp', command='bin/myapp')
Step 2: Fit your model to your environments
-------------------------------------------
Your model from step 1 is abstract: it does not mention the names of the
servers you deploy to.
By describing an environment you tell batou how your abstract model should
actually be applied: on your local development machine, to a vagrant setup, or
on servers on the network.
Here's an environment specification that sets up an application on multiple
hosts and provides an override for the publicly visible address.
.. code-block:: ini
[environment]
host_domain = fcio.net
[host:host01]
components = nginx, haproxy, varnish
[host:host02]
components = myapp
[host:host03]
components = myapp
[host:host04]
components = postgresql
[component:nginx]
server_name = staging.example.com
Features
--------
* Run the same command to deploy locally, to Vagrant, or to remote clusters.
* Use different versions of batou in different projects. Ensure everybody uses the same version.
* Check before deploying whether your configuration is internally consistent and consistent with what has been deployed before.
* Convergent, idempotent components are fast to deploy.
* Resume partial deployments where they were aborted.
* Store database passwords, SSH keys, SSL certificates or other secret data with on the-fly decryption. Manage access to secrets per environment and user.
* Use Jinja2 templates to easily create dynamic configuration.
* Dynamically connect services during deployments and track their dependencies.
* Few run-time requirements on your servers: only Python 2.7 and SSH are needed.
* Use pre-defined components to manage files, python environments, supervisor, cronjobs, and more.
* Writing your own components is easy and you can use additional Python package dependencies.
User guide
----------
This part of the documentation, begins with some background information about Requests, then focuses on step-by-step instructions for getting the most out of batou.
.. toctree::
:maxdepth: 2
user/intro
user/install
user/quickstart
user/advanced
Command line
------------
If you are looking for information on what commands the batou CLI provides then this is for you.
.. toctree::
:maxdepth: 2
cli/index
Components
----------
This is the list of components that batou provides -- builtin and through the `batou_ext` package:
.. toctree::
:maxdepth: 2
components/files.txt
components/downloads-vcs.txt
components/cmmi.txt
components/python.txt
components/services.txt
API
---
If you are looking for information on a specific function, class or method, this part of the documentation is for you.
.. toctree::
:maxdepth: 2
api/component
api/environment
api/templates
api/utilities
Contributor guide
-----------------
If you want to contribute to the project, this part of the documentation is for you.
.. toctree::
:maxdepth: 1
dev/contributing
dev/todo
dev/authors
Support
-------
batou itself is released "as is". We hang around #batou in the Freenode IRC
network. You can also report bugs to our `bugtracker `_.
.. rubric:: Commercial support
We will be happy to give you commercial support for batou: feature
implementation, bug fixing, consulting, or education.
To get in touch, send an email to `mail@flyingcircus.io
`_ and we'll
be happy to discuss your requirements.
Resources
---------
.. toctree::
:maxdepth: 1
changes
Presentations from conferences:
* `EuroPython 2013 - batou (talk slides) `_
* `PyConDE 2013 - batou (talk video, German) `_