Fabric deployment with virtualenv support in the server

fabfile.py

"""
This fabfile deploys projects versioned in git and that use a virtualenv in the
remote server.

The deploy and deploy_version tasks are framework-independent.

The freshdb task is specific for Django projects.

The restart task is for projects deployed using FastCGI.

TODO:
  * Bootstrap command to create a virtualenv and install requirements with pip.

"""

from __future__ import with_statement

from fabric.api import cd, env, require, run, settings

env.project_name = 'project_name'

env.user = 'remote_user'
env.hosts = ['your_host.com']
env.home_path = '/home/remote_user'
env.path = '%s/path/to/project' % env.home_path
env.virtualenv_dir = '%s/env' % env.home_path


def _virtualenv(command):
    """Execute a command in remote host inside a virtualenv."""
    require('virtualenv_dir')
    run('source %s/bin/activate && %s' % (env.virtualenv_dir, command))


def deploy():
    """Update the remote code to the last version and make it visible."""
    deploy_version()


def deploy_version(version=None):
    """Update the remote code to a specific version and make it visible."""
    require('path')
    with cd(env.path):
        run('git checkout master')
        run('git pull')
        if version is not None:
            run('git checkout %s' % version)
    restart()


def freshdb():
    """Delete the remote DB and make a fresh syncdb."""
    require('path')
    with cd(env.path):
        with settings(warn_only=True):
            run('rm chattr.db')
        _virtualenv('python manage.py syncdb --noinput')


def restart():
    """Restart the FastCGI process (to make changes visible)."""
    require('home_path')
    with settings(warn_only=True):
        run('kill $(cat %(home_path)s/run/chattr.pid)' % env)
    run('sh %(path)s/conf/chattr_fastcgi.sh' % env)