magento-test/app/code/Magento/PageCache/etc/config.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Store:etc/config.xsd">
    <default>
        <design>
            <invalid_caches>
                <full_page/>
            </invalid_caches>
        </design>
        <system>
            <full_page_cache>
                <varnish6>
                    <path>varnish6.vcl</path>
                </varnish6>
                <varnish5>
                    <path>varnish5.vcl</path>
                </varnish5>
                <varnish4>
                    <path>varnish4.vcl</path>
                </varnish4>
                <ttl>86400</ttl>
                <caching_application>1</caching_application>
                <default>
                    <access_list>localhost</access_list>
                    <backend_host>localhost</backend_host>
                    <backend_port>8080</backend_port>
                    <ttl>86400</ttl>
                    <grace_period>300</grace_period>
                </default>
            </full_page_cache>
        </system>
    </default>
</config>