runtime-generated fabric connection functions, yay

fabextras.py

from fabric.api import env
import os
import string

_conf_root = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'conf')
_conf_dirs = [x for x in os.listdir(_conf_root)
              if os.path.isdir(os.path.join(_conf_root, x))
              and x != 'base']

def _mk_sethost_fn(host_dicts, context):
    def inner():
        """ (Autogenerated host connection function.) """
        env.update(context)
        hoststrings = []
        if env.key_filename == None: env.key_filename = []
        for host in host_dicts:
            hostname = host['hostname']
            user = host.get('user', '')
            port = host.get('port', '')
            hoststring = '%s%s%s' % (user and user + '@',
                                   hostname,
                                   port and ':' + str(port),
                                  )
            hoststrings.append(hoststring)
            key_filename = host.get('key_filename')
            if key_filename:
                env.key_filename.append(key_filename)
        env.hosts = hoststrings
    return inner

for x in _conf_dirs:
    try:
        module_name = string.join(('conf', x, 'hosts'), '.')
        module = __import__(module_name, fromlist=['hosts', 'prefix'])
        hosts = module.hosts
        context = {
            'prefix': module.prefix,
        }

        module_name = string.join(('conf', x, 'gunicorn'), '.')
        module = __import__(module_name, fromlist=['pidfile'])
        context['pidfile'] = module.pidfile
        locals()[x] = _mk_sethost_fn(hosts, context)
    except ImportError:
        pass

hosts.py

# this would go in conf/sample/hosts.py

import os
current_dir = os.path.dirname(os.path.abspath(__file__))

hosts = (
    {
        'hostname': '0.0.0.0', # IP address here
        'port': 666, # port here
        'key_filename': os.path.join(current_dir, 'ssh_key'), # symlink a ssh key in if you need one
    },
)

virtualenv_path = '/path/to/your/virtual-env' # location of the virtualenv on that host
project_path = '/path/to/your/project' # location to the project on that host.

activate_cmd = 'source %s/bin/activate' % virtualenv_path
prefix = '%s && cd %s' % (activate_cmd, project_path)