magento-test/app/code/Magento/CacheInvalidate/etc/events.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:framework:Event/etc/events.xsd">
    <event name="clean_cache_by_tags">
        <observer name="invalidate_varnish" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
    <event name="adminhtml_cache_flush_system">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\FlushAllCacheObserver"/>
    </event>
    <event name="clean_media_cache_after">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\FlushAllCacheObserver"/>
    </event>
    <event name="clean_catalog_images_cache_after">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\FlushAllCacheObserver"/>
    </event>
    <event name="assigned_theme_changed">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
    <event name="catalogrule_after_apply">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
    <event name="adminhtml_cache_refresh_type">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\FlushAllCacheObserver"/>
    </event>
    <event name="adminhtml_cache_flush_all">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\FlushAllCacheObserver"/>
    </event>
    <event name="assign_theme_to_stores_after">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\FlushAllCacheObserver"/>
    </event>
    <event name="controller_action_postdispatch_adminhtml_system_currency_saveRates">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
    <event name="controller_action_postdispatch_adminhtml_system_config_save">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
    <event name="controller_action_postdispatch_adminhtml_catalog_product_action_attribute_save">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
    <event name="controller_action_postdispatch_adminhtml_catalog_product_massStatus">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
    <event name="controller_action_postdispatch_adminhtml_system_currencysymbol_save">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
    <event name="clean_cache_after_reindex">
        <observer name="flush_varnish_pagecache" instance="Magento\CacheInvalidate\Observer\InvalidateVarnishObserver"/>
    </event>
</config>