fabfile for deployment. (fab fabfile.py deploy:host=name.of.server.com)

fabfile.py

from fabric.contrib.files import append, exists, sed
from fabric.api import env, local, run
from os import path
import random

REPO_URL = 'https://github.com/username/repo.git'
SITES_FOLDER = '/home/username/sites/'
PROJECT_NAME = 'projectName'

def deploy():
	_create_directory_structure_if_necessary(env.host)
	source_folder = path.join(SITES_FOLDER, env.host, 'source')
	_get_latest_source(source_folder)
	_update_settings(source_folder, env.host)
	_update_virtualenv(source_folder)
	_update_static_files(source_folder)
	_update_database(source_folder)

def _create_directory_structure_if_necessary(site_name):
	base_folder = path.join(SITES_FOLDER, site_name)
	run('mkdir -p %s' % (base_folder))
	for subfolder in ('database', 'static', 'virtualenv', 'source'):
		run('mkdir -p %s/%s' % (base_folder, subfolder))

def _get_latest_source(source_folder):
	if exists(path.join(source_folder, '.git')):
		run('cd %s && git fetch' % (source_folder,))
	else:
		run('git clone %s %s' % (REPO_URL, source_folder))
	current_commit = local("git log -n 1 --format=%H", capture=True)
	run('cd %s && git reset --hard %s' % (source_folder, current_commit))

def _update_settings(source_folder, site_name):
	settings_path = path.join(source_folder, PROJECT_NAME, 'settings.py')
	sed(settings_path, "DEBUG = True", "DEBUG = False")
	sed(settings_path, 'DOMAIN = "localhost"', 'DOMAIN = "%s"' % (site_name,))
	secret_key_file = path.join(source_folder, PROJECT_NAME, 'secret_key.py')
	if not exists(secret_key_file):
		chars = 'abcdefghijklmnopqrstuvwxyz012456789!@#$%^&*(-_=+)'
		key = ''.join(random.SystemRandom().choice(chars) for _ in range(50))
		append(secret_key_file, "SECRET_KEY = '%s'" % (key,))
	append(settings_path, 'from .secret_key import SECRET_KEY')

def _update_virtualenv(source_folder):
	virtualenv_folder = path.join(source_folder, '../virtualenv')
	if not exists(path.join(virtualenv_folder, 'bin', 'pip')):
		run('virtualenv --python=python3 %s' % (virtualenv_folder,))
	run('%s/bin/pip install -r %s/requirements.txt' % (
		virtualenv_folder, source_folder
	))

def _update_static_files(source_folder):
	run('cd %s && ../virtualenv/bin/python3 manage.py collectstatic --noinput' % (
		source_folder,
	))

def _update_database(source_folder):
	run('cd %s && ../virtualenv/bin/python3 manage.py syncdb --migrate --noinput' % (source_folder,))