Return a ConnectionPool instance of given host
    :param socket_timeout:
        socket timeout for each connection in seconds

def get_con_pool(host,
                 key_file=None,
                 cert_file=None,
                 socket_timeout=15.0,
                 max_pool_size=3,
                 verify_https=True):
    """
    Return a ConnectionPool instance of given host
    :param socket_timeout:
        socket timeout for each connection in seconds
    """
    kwargs = {
        "timeout": socket_timeout,
        "maxsize": max_pool_size,
        "block": True,
        }

    if key_file is not None and cert_file is not None:
        kwargs["key_file"] = key_file
        kwargs["cert_file"] = cert_file

    if urlparse(host).scheme == "https":
        kwargs["ssl_version"] = ssl.PROTOCOL_TLSv1
        if verify_https:
            kwargs["cert_reqs"] = "CERT_REQUIRED"
            kwargs["ca_certs"] = getattr(settings, "RESTCLIENTS_CA_BUNDLE",
                                         "/etc/ssl/certs/ca-bundle.crt")

    return connection_from_url(host, **kwargs)