def run_pip_install(upgrade=0):
    """
    Installs the requirement.txt file on the given server.

    Usage::

        fab <server> run_pip_install
        fab <server> run_pip_install:upgrade=1

    :param upgrade: If set to 1, the command will be executed with the
      ``--upgrade`` flag.

    """
    command = 'pip install -r {0}'.format(
        settings.FAB_SETTING('SERVER_REQUIREMENTS_PATH'))
    if upgrade:
        command += ' --upgrade'
    run_workon(command)
Installs the requirement.txt file on the given server.

    Usage::

        fab <server> run_pip_install
        fab <server> run_pip_install:upgrade=1

    :param upgrade: If set to 1, the command will be executed with the
      ``--upgrade`` flag.