On my MacBook Pro running macOS Big Sur, I have the following Docker credentials helpers installed:
% docker-credential-[TAB]
docker-credential-desktop docker-credential-ecr-login docker-credential-osxkeychain
I don't remember installing docker-credential-desktop and docker-credential-osxkeychain so it must have got installed when I installed Docker Desktop.
I know about the docker-credential-ecr-login and docker-credential-osxkeychain, but I couldn't find any documentation on docker-credential-desktop. Many people are wondering about this too. I assume it's something to do specifically with Docker Desktop.
Running docker-credential-desktop list gives the same output as docker-credential-osxkeychain list, which is what some users found on GitHub found as well.
% docker-credential-desktop list
{"https://<account-id>.dkr.ecr.<region>.amazonaws.com":"AWS"}
% docker-credential-osxkeychain list
{"https://<account-id>.dkr.ecr.<region>.amazonaws.com":"AWS"}
This leads me to think that docker-credential-desktop is just a wrapper around docker-credential-osxkeychain. However, looking at the actual binary, the docker-credential-desktop is 14M compared to 2.8M for docker-credential-osxkeychain.
% ls -ahl /Applications/Docker.app/Contents/Resources/bin/docker-credential-*
-rwxr-xr-x 1 14M Sep 5 16:14 docker-credential-desktop
-rwxr-xr-x 1 10M Sep 5 16:14 docker-credential-ecr-login
-rwxr-xr-x 1 2.8M Jul 7 10:59 docker-credential-osxkeychain
So what is the docker-credential-desktop credential helper? Why is docker-credential-osxkeychain insufficient?