Controller/Adminhtml/FastlyCdn/Purge/Quick.php
private function isHostInDomainList($host)
    {
        $urlTypes = [
            UrlInterface::URL_TYPE_LINK,
            UrlInterface::URL_TYPE_DIRECT_LINK,
            UrlInterface::URL_TYPE_WEB,
            UrlInterface::URL_TYPE_MEDIA,
            UrlInterface::URL_TYPE_STATIC
        ];
        $secureScheme = [true, false];

        foreach ($this->storeManager->getStores() as $store) {
            /** @var \Magento\Store\Model\Store $store */
            foreach ($urlTypes as $urlType) {
                foreach ($secureScheme as $scheme) {
                    $shopHost = \Zend_Uri::factory($store->getBaseUrl($urlType, $scheme))->getHost();
                    if ($host === $shopHost) {
                        return true;
                    }
                }
            }
        }
        return false;
    }
private function isHostInDomainList($host)
    {
        $urlTypes = [
            UrlInterface::URL_TYPE_LINK,
            UrlInterface::URL_TYPE_DIRECT_LINK,
            UrlInterface::URL_TYPE_WEB,
            UrlInterface::URL_TYPE_MEDIA,
            UrlInterface::URL_TYPE_STATIC
        ];
        $secureScheme = [true, false];

        foreach ($this->storeManager->getStores() as $store) {
            /** @var \Magento\Store\Model\Store $store */
            foreach ($urlTypes as $urlType) {
                foreach ($secureScheme as $scheme) {
                    $shopHost = \Zend_Uri::factory($store->getBaseUrl($urlType, $scheme))->getHost();
                    if ($host === $shopHost) {
                        return true;
                    }
                }
            }
        }
        return false;
    }
Checks if host is one of Magento's configured domains.

@param $host
@return bool
@throws \Zend_Uri_Exception