Module dependency

[daniel-ifrim]

It looks like observer 'invalidate_varnish' Fastly\Cdn\Observer\InvalidateVarnishObserver from vendor/fastly/magento2/etc/events.xml never runs.

I'm looking into app/etc/config.php and Fastly_Cdn module is before Magento_CacheInvalidate.
It means observer 'invalidate_varnish' from Magento_CacheInvalidate isn't replaced by the observer from Fastly_Cdn module Fastly\Cdn\Observer\InvalidateVarnishObserver.
More or less 'clean_cache_by_tags' doesn't work with Fastly_Cdn module.
'clean_cache_by_tags' is called by indexer and other code. One example would be when a product gets out of stock after customer purchase via checkout.

A quick look into module and I came up with these module.xml dependencies:

<sequence>
            <module name="Magento_Store"/>
            <module name="Magento_PageCache"/>
            <module name="Magento_CacheInvalidate"/>
</sequence>

[daniel-ifrim]

The fix for this issue is in version 1.2.28.
Thank you.