Docker Login to gcr.io in Powershell

Question

I'm trying to log in to Google's Container Registry on Windows 10 by using a JSON Key file. I have this working without issues on my Mac so the keyfile is definitely working.

First off I had issues getting the docker login function to accept the contents of the JSON key file. I've tried running the "/set /p PASS..." command in CMD and I've tried something along the lines of this in Powershell:

docker login -u _json_key -p "$(Get-Content keyfile.json)" https://gcr.io

These all result in either an error or this:

"docker login" requires at most 1 argument.

Since I couldn't get this to work, I ran:

docker login -u _json_key https://gcr.io

And then just removed all breaks from the JSON file manually, copied it to clipboard and pasted it when prompted for my password.

That results in:

Login Succeeded

Problem solved! Right?

Well apparently not. I was still unable to pull my images and when I ran docker info the only registry listed was "https://index.docker.io/v1/".

I've tried starting Powershell as admin, and restarted and reset docker but nothing seems to help.

Anyone got any clue what is going on? How do I debug this?

I'm running Docker version 17.12.0 (stable)

Answer 1

I found a solution that works for both Windows (in PowerShell) and bash. The secret is to use the "provide a password using stdin".

cat gcr_registry-ro.json | docker login -u _json_key --password-stdin https://gcr.io
Login Succeeded

Help text and versions:

PS C:\Users\andy> docker login --help

Usage:  docker login [OPTIONS] [SERVER]

Log in to a Docker registry

Options:
  -p, --password string   Password
      --password-stdin    Take the password from stdin
  -u, --username string   Username
PS C:\Users\andy> docker -v
Docker version 18.06.1-ce, build e68fc7a
PS C:\Users\andy>