Setting up container registry for kubeflow - docker

Question

I am using ubuntu 20.04
while following book -> https://www.oreilly.com/library/view/kubeflow-for-machine/9781492050117/
on page 17, it says the following (only relevant parts) which I don't understand....
You will want to store container images called a
container registry. The container registry will be accessed by your Kubeflow cluster.
I am going to use docker hub as container registry. Next
we'll assume that you've set your container registry via an environment variable
$CONTAINER_REGISTRY, in your shell" NOTE: If you use registry that isn't on Google Cloud
Platform, you will need to configure Kubeflow pipelines container builder to have access to
your registry by following the Kaniko configuration guide -> https://oreil.ly/88Ep-
First, I do not understand how to set container registry through environment variable, am I supposed to give it a link??
Second, I've gone into Kaniko config guide and did everything as told -> creating config.json with "auth":"mypassword for dockerhub". After that In the book it says:
To make sure your docker installation is properly configured, you can write one line Dc and
push it to your registry."
Example 2.7 Specify the new container is built on top of Kubeflow's
container
FROM gcr.io/kubeflow-images-public/tensorflow-2.1.0-notebook-cpu:1.0.0
Example 2.8 Build new container and push to registry for use
IMAGE="${CONTAINER_REGISTRY}/kubeflow/test:v1"
docker build -t "${IMAGE}" -f Dockerfile . docker push "${IMAGE}"
I've created Dockerfile with code from Example2.7 inside it, then ran code from Example 2.8 however not working.

Answer 1

Make sure that:
You set the environment variable using export CONTAINER_REGISTRY=docker.io/your_username in your terminal (or in your ~/.bash_profile and run source ~/.bash_profile).
Your .docker/config.json does not have your password in plain text but in base64, for example the output of echo -n 'username:password' | base64
The docker build and the docker push are two separate commands, in your example they're seen as one command, unlike the book.