[FIXED] What is the purpose of pushing an image in a CI/CD pipeline?

Issue

Context: Reading through this blog post.

Pushing images to a registry seems to be the "right thing to do" ... but I don't understand why.

What purpose does this serve? Is it because the server I ssh into needs to have a local copy of the image? And to do that, one approach is to pull an image from a registry?

Solution

Usually, you use a CI, CD pipeline when you want to streamline your build / test/ deploy process, and usually this happens if you have a production infrastructure to maintain that is actually critical to your business.

There is no need for a CI/CD pipeline if you're just playing around / prototyping IMO, in which case you can build you docker images on the machine directly, or ssh an image over. That's perfectly reasonable.

Look at the 'registry' as a repository of your binary image (i.e. a fixed version of your code that ideally is versioned and you know works)

Then deploying is as simple as telling your servers to pull the image and run it, from anywhere.

On a flexible architecture, you might have nodes coming up or going down at any time, and they need to be able to pull the latest code from somewhere to get back up and running automatically, at any time, without intervention.

Answered By - MrE

Answer Checked By - David Goodson (PHPFixing Volunteer)