How is the Docker Host Certificate Authentication credential type used by jenkins?

Question

I'm configuring the Docker Plugin in jenkins and I see that I need to add a Docker Host Certificate Authentication credential. I understand that this is a cert/key pair that is used to authenticate to a docker host, but I'm not finding information about how jenkins connects to the docker host. Does this cert/key pair need to be the same one used by the jenkins user on the jenkins server when jenkins needs to ssh into a slave? Or can it be a new cert/key pair that I generate to only be used by the Docker Plugin?

Answer 1

Docker uses client-server architecture for sending commands to a daemon.

If you run docker version you should see two parts versions server and client.

On localhost, docker client connects to the server by unix socket. But docker allows remote API for connecting from anywhere. This connection protected by TLS and you need certificates for client-server authentication.

Jenkins connect to remote REST API.

You can see Jenkins docker plugin depends from Java docker API