An example Fabric build file with the ability to `build` and `deploy` to a variety of targets.

fabfile.py

import os
from fabric.api import *
from fabric.context_managers import lcd
from fabric.contrib.project import rsync_project


@task
def build(composer_extra=""):
    with lcd('src/private'):
        local("composer install %s" % composer_extra)
    with lcd('src'):
        local("npm install")
        local("gulp --production")


@task
def prod():
    env.WEB_SRV_ID = 'nginx'
    env.hosts.append('admin@example.com')
    env.DEPLOY_TO = '/content/www/'


@task
def dev():
    env.WEB_SRV_ID = 'admin'
    env.hosts.append('admin@dev.example.com')
    env.DEPLOY_TO = '/var/www/example/'


@task
def deploy():
    if env.WEB_SRV_ID == 'nginx':
        sudo('chmod -R g+w %s' % env.DEPLOY_TO)
    rsync_project(
        local_dir=os.getcwd() + '/src',
        remote_dir=env.DEPLOY_TO,
        extra_opts='--no-perms --omit-dir-times -l --exclude-from=%s/build/sync.ignore' % os.getcwd(),
        exclude=[],
        delete=True
    )
    if env.WEB_SRV_ID == 'nginx':
        sudo('chown -R {0}:{0} {1}'.format(env.WEB_SRV_ID, env.DEPLOY_TO))