What happens if you need to drag and drop 2 php files and someone makes an HTTP request that gets processed right in-between the update of each file ?

They will surely get something weird, an error at best. Containers allow transactional deployments and FTP does not.

True. Perhaps you can upload to a temporary folder first, rename the old production folder to something else, and rename the temporary folder to the normal production folder. You may serve a 404 error if someone manages to do a request between the two renaming operation but I'm sure it's fine.

It's definitely better, but then it's not ZDD is it :)

Or just change a symlink to the new folder

> zero downtime deployments

> drag and drop a PHP file

These two things run in conflict. It’s not about not dropping requests - It’s about a sane state and error reproducibility. If you drag the wrong file, there will be plenty of downtime...

True. But if you apply the wrong YAML file in kubernetes too. If your container has the wrong version too.

Anyway, I'm not advising for uploading PHP files through FTP on live servers in 2020, I took it as an example of something we used to do without kubernetes.

This is an oversimplification of the problem. You need to drain the requests to the old version then wait until the new one passes a health check before rerouting the traffic