def _parse_port_string_to_rule()

in cartography/intel/gcp/compute.py [0:0]

• 22 lines of code
• 5 McCabe index (conditional complexity)

def _parse_port_string_to_rule(port, protocol, fw_partial_uri, is_allow_rule):
    """
    Takes a string argument representing a GCP firewall rule port or port range and returns a dict that is easier to
    load into Neo4j.

    Example 1 - single port range:
    Input: `'0-65535', 'tcp', fw_id, is_allow_rule=True`
    Output: `{fromport: 0, toport: 65535, protocol: tcp, ruleid: fw_id/allow/0to65535tcp}`

    Example 2 - single port
    Input: `'80', fw_id, is_allow_rule=False`
    Output: `{fromport: 80, toport: 80, protocol: tcp, ruleid: fw_id/deny/80tcp}`

    Example 3 - ICMP (no ports)
    Input: `None, fw_id, is_allow_rule=True`
    Output: `{fromport: None, toport: None, protocol: icmp, ruleid: fw_id/allow/icmp}`

    :param port: A string representing a single port or a range of ports.  Example inputs include '22' or '12345-12349'
    :param protocol: The protocol
    :param fw_partial_uri: The partial URI of the firewall
    :param is_allow_rule: Whether the rule is an `allow` rule.  If false it is a `deny` rule.
    :return: A dict containing fromport, toport, a ruleid, and protocol
    """
    # `port` can be a range like '12345-12349' or a single port like '22'

    if port is None:
        # Keep the port range as the empty string
        port_range_str = ''
        fromport = None
        toport = None
    else:
        # Case 1 - port range: '12345-12349'.split('-') => ['12345','12349'].
        # Case 2 - single port: '22'.split('-') => ['22'].
        port_split = port.split('-')

        # Port range
        if len(port_split) == 2:
            port_range_str = f"{port_split[0]}to{port_split[1]}"
            fromport = int(port_split[0])
            toport = int(port_split[1])
        # Single port
        else:
            port_range_str = f"{port_split[0]}"
            fromport = int(port_split[0])
            toport = int(port_split[0])

    rule_type = 'allow' if is_allow_rule else 'deny'

    return {
        'ruleid': f"{fw_partial_uri}/{rule_type}/{port_range_str}{protocol}",
        'fromport': fromport,
        'toport': toport,
        'protocol': protocol
    }