Pushing images to registry in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of pushing a Docker image to a registry?

Pushing a Docker image to a registry stores the image in a central place so others can download and use it on their machines or servers.

beginner

Which command tags a local Docker image before pushing it to a registry?

The command is docker tag <local-image> <registry-url>/<repository>:<tag>. This prepares the image with the correct name for the registry.

beginner

What command do you use to push a Docker image to a registry?

Use docker push <registry-url>/<repository>:<tag> to upload the image to the registry.

beginner

Why do you need to log in to a Docker registry before pushing images?

Logging in with docker login lets the registry know who you are and if you have permission to upload images.

intermediate

What happens if you try to push an image without tagging it with the registry URL?

Docker will try to push to the default Docker Hub repository. If the image name is not recognized there, the push will fail.

Which command tags a Docker image for pushing to a registry?

A docker build myimage

B docker tag myimage myregistry.com/myrepo:latest

C docker login myregistry.com

D docker push myimage

Tagging prepares the image with the registry URL and repository name before pushing.

What is the correct command to upload an image to a Docker registry?

A docker tag myimage myrepo:latest

B docker pull myregistry.com/myrepo:latest

C docker push myregistry.com/myrepo:latest

D docker run myregistry.com/myrepo:latest

The 'docker push' command uploads the image to the specified registry.

Why do you run 'docker login' before pushing an image?

A To authenticate and get permission to push images

B To download images from the registry

C To build the Docker image

D To remove old images

'docker login' authenticates your user to the registry for pushing images.

If you push an image without tagging it with a registry URL, where does Docker try to push it?

A Docker Hub (default public registry)

B Local machine only

C Private registry automatically

D It does not push anywhere

Docker defaults to Docker Hub if no registry URL is specified.

What must you do before pushing a newly built Docker image?

A Pull the image from the registry

B Run the image locally

C Delete old images

D Tag the image with the registry and repository name

Tagging the image with the registry URL is required to push it correctly.

Explain the steps to push a Docker image to a remote registry.

Think about preparing the image, authenticating, and then uploading.

Why is tagging important before pushing a Docker image to a registry?

Consider how Docker knows where to send the image.