Getting Started with Container Registry

Ready to push the image to a registry? In this post, we will discuss how to get started with Container Registry.

Upon sign in successfully, you should be able to see the page below.

Navigate the UIs, and the repositiries should be empty. Let’s build and push some containers

Make sure you have docker installed

Click on User Profile to get the password for container-registry.

Copy the CLI secret, and user it to with docker login in below.

username is case-sensitive

docker login  -u USER_NAME

Build image

Get the minimum hello world app in Go from this cncf-demo repo

username here should be all lowercase, despite you have upper case for actual username

git clone https://github.com/WLun001/cncf-demo
cd cncf-demo/examples/hello-world

# build image with multiple tags
docker build -t hello-world:1.0 -t /USER_NAME/hello-world:1.0 .

To view built images

Both images have the same Image ID, showing two images because were tagged differently with -t flag

$ docker images

REPOSITORY                     TAG      IMAGE ID       CREATED          SIZE
/USER_NAME/hello-world   1.0      cf417f3ab6cf   18 seconds ago   12MB
hello-world                    1.0      cf417f3ab6cf   18 seconds ago   12MB

Push image

To push the image

$ docker push /USER_NAME/hello-world:1.0

The push refers to repository [/USER_NAME/hello-world]
3d8d5e255593: Pushed
543a4c33c12f: Pushed
50644c29ef5a: Layer already exists
1.0: digest: sha256:9463678f592aa6e5ef72dcf735ce60a5aad53359e68dd5e48b14b6b6d1b2c753 size: 947

Go back to the console UI, should see the image has been pushed

The image size on local is 12 MB, but the UI showing 5.90 MB. This is because the image is compressed after pushed, or rather only 5.90 MB is required to download this image.