Why does one need to login into the Azure Container registry before pulling the images from it, i.e. az login is not good enough?

Question

I am already logged in into Azure through az login , however in order to pull images from an ACR I had to also run az acr login - I was not even asked for credentials, because the same account is used.

I do not understand why is az login not good enough?

Answer 1

Afaik az acr login actually does perform a docker login with your local docker runtime under the hood. As your docker runtime does not know anything about Azure, just az login does not suffice. You could do the same manually be getting the credentials from your ACR and then run docker login my.azurecr.io --username my --password xxx

az acr login is not required to work with the ACR resource, but only with the registry from a docker perspective, such as pulling or pushing images.