validators.py

import ipaddress

from rest_framework import serializers

from .models import Consumer


class BaseValidator(object):
    def __init__(self, config):
        self.config = config

    def __call__(self):
        # Method should only raise serializer.ValidationError in case of errors
        pass


class ConsumerValidator(BaseValidator):
    def __call__(self):
        # Check valid consumer_id if any given
        if (
            self.config.get('consumer_id') and
            not Consumer.objects.filter(pk=self.config['consumer_id']).first()
        ):
            raise serializers.ValidationError({
                'config': 'Invalid consumer'
            })


class IPListValidator(BaseValidator):
    def __call__(self):
        # Remove duplicated values
        self.config['whitelist'] = list(set(self.config.get('whitelist', [])))
        self.config['blacklist'] = list(set(self.config.get('blacklist', [])))

        try:
            [
                ipaddress.ip_network(ip)
                for ip in self.config['whitelist']+self.config['blacklist']
            ]
        except (ipaddress.AddressValueError, ValueError) as err:
            raise serializers.ValidationError({
                'config': err
            })


class WhitelistBlacklistMutuallyExclusive(BaseValidator):
    def __call__(self):
        # Whitelist and blacklist are mutually exclusives
        if self.config.get('whitelist') and self.config.get('blacklist'):
            raise serializers.ValidationError({
                'config': 'Whitelist and blacklist are mutually exclusive',
            })


validator_classes = {
    'ip-restriction': [
        WhitelistBlacklistMutuallyExclusive,
        IPListValidator,
        ConsumerValidator,
    ],
    'request-termination': [ConsumerValidator, ],
    'acl': [WhitelistBlacklistMutuallyExclusive, ]
}