How to know if docker is already logged in to a docker registry server

Question

I\'m not sure if I have already logged in to a docker registry in cmd line by using cmd: docker login. How can you test or see whether you are logged in or not, without tryi

Answer 1

The answers here so far are not so useful:

• docker info no longer provides this info
• docker logout is a major inconvenience - unless you already know the credentials and can easily re-login
• docker login response seems quite unreliable and not so easy to parse by the program

My solution that worked for me builds on @noobuntu's comment: I figured that if I already known the image that I want to pull, but I'm not sure if the user is already logged in, I can do this:

try pulling target image
-> on failure:
   try logging in
   -> on failure: throw CannotLogInException
   -> on success:
      try pulling target image
      -> on failure: throw CannotPullImageException
      -> on success: (continue)
-> on success: (continue)