Pushing and pulling images in GCP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to push a Docker image to Google Container Registry.

GCP

docker [1] gcr.io/my-project/my-image:latest

Drag options to blanks, or click blank then click option'

Apush

Bpull

Crun

Dbuild

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'docker pull' instead of 'docker push'.

Using 'docker run' which runs containers, not pushes images.

The docker push command uploads your image to the registry.

2fill in blank

medium

Complete the command to pull a Docker image from Google Container Registry.

GCP

docker [1] gcr.io/my-project/my-image:latest

Drag options to blanks, or click blank then click option'

Abuild

Bpush

Cpull

Drun

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'docker push' instead of 'docker pull'.

Using 'docker build' which creates images locally.

The docker pull command downloads the image from the registry to your local machine.

3fill in blank

hard

Fix the error in the command to tag a local image for pushing to Google Container Registry.

GCP

docker tag my-image:latest [1]/my-project/my-image:latest

Drag options to blanks, or click blank then click option'

Agcr.io

Bregistry.hub.docker.com

Clocalhost

Ddocker.io

Attempts:

3 left

💡 Hint

Common Mistakes

Using Docker Hub hostnames instead of Google Container Registry.

Using 'localhost' which is not a remote registry.

Images must be tagged with the Google Container Registry hostname gcr.io before pushing.

4fill in blank

hard

Fill both blanks to complete the command that authenticates Docker to Google Container Registry.

GCP

gcloud auth [1]-docker [2]

Drag options to blanks, or click blank then click option'

Aconfigure

Blogin

C--quiet

D--no-quiet

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'login' instead of 'configure'.

Omitting the quiet flag causing prompts.

The command gcloud auth configure-docker --quiet sets up Docker authentication silently.

5fill in blank

hard

Fill both blanks to complete the command that lists tags for an image in a Google Container Registry repository.

GCP

gcloud container images list-[1] gcr.io/my-project/[2]

Drag options to blanks, or click blank then click option'

Atags

Bfilter

Cmy-image

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'delete' instead of 'tags' which removes images.

Omitting the image name causing 'not found' error.

The command gcloud container images list-tags gcr.io/my-project/my-image lists tags for the specified image.

Practice

1. What does the docker push command do in Google Cloud Platform?

easy

A. Downloads a container image from Google Container Registry

B. Uploads your container image to Google Container Registry

C. Deletes a container image from your local machine

D. Builds a new container image from a Dockerfile

Solution

1. Step 1: Understand the purpose of docker push

   The docker push command uploads your local container image to a remote registry like Google Container Registry.

2. Step 2: Differentiate from other commands

   docker pull downloads images, docker build creates images, and deleting is a separate action.

3. Final Answer:

   Uploads your container image to Google Container Registry -> Option B

4. Quick Check:

   Push = Upload image to registry [OK]

Hint: Push means upload image to cloud registry [OK]

Common Mistakes:

• Confusing push with pull
• Thinking push builds the image
• Assuming push deletes images

2. Which of the following is the correct syntax to tag a local Docker image named myapp with the Google Container Registry path gcr.io/my-project/myapp:v1?

easy

A. docker tag myapp gcr.io/my-project/myapp:v1

B. docker push myapp gcr.io/my-project/myapp:v1

C. docker pull myapp gcr.io/my-project/myapp:v1

D. docker build myapp gcr.io/my-project/myapp:v1

Solution

1. Step 1: Identify the tagging command

   The docker tag command assigns a new name (including registry path) to an existing local image.

2. Step 2: Confirm correct syntax

   The syntax is docker tag SOURCE_IMAGE TARGET_IMAGE, so docker tag myapp gcr.io/my-project/myapp:v1 is correct.

3. Final Answer:

   docker tag myapp gcr.io/my-project/myapp:v1 -> Option A

4. Quick Check:

   Tag syntax = docker tag SOURCE TARGET [OK]

Hint: Tag uses 'docker tag source target' syntax [OK]

Common Mistakes:

• Using push or pull instead of tag
• Reversing source and target images
• Confusing build with tag

3. Given the commands below, what will be the result of running docker images?

docker tag myapp gcr.io/my-project/myapp:v2
docker push gcr.io/my-project/myapp:v2

medium

A. The local image list will only show myapp without the tag

B. The local image list will be empty

C. The local image list will include gcr.io/my-project/myapp:v2

D. The local image list will show myapp:v2 but not the full registry path

Solution

1. Step 1: Understand tagging effect on local images

   Tagging creates a new name for the same local image, so gcr.io/my-project/myapp:v2 appears locally.

2. Step 2: Recognize push does not remove local images

   Pushing uploads the image but does not delete local copies, so the tagged image remains listed.

3. Final Answer:

   The local image list will include gcr.io/my-project/myapp:v2 -> Option C

4. Quick Check:

   Tag adds local name; push uploads but keeps local image [OK]

Hint: Tag adds local name; push uploads but keeps local image [OK]

Common Mistakes:

• Thinking push deletes local images
• Assuming tag does not create new local name
• Confusing image names without registry path

4. You tried to push an image with the command docker push myapp:v1 but got an error saying the repository was not found. What is the most likely cause?

medium

A. You forgot to tag the image with the full registry path before pushing

B. You need to run docker pull before pushing

C. The image name myapp:v1 is invalid syntax

D. You must delete the local image before pushing

Solution

1. Step 1: Understand push requires full registry path

   To push to Google Container Registry, the image must be tagged with the full path like gcr.io/project-id/image:tag.

2. Step 2: Identify missing tag as cause of error

   Using only myapp:v1 lacks registry info, so the push command cannot find the remote repository.

3. Final Answer:

   You forgot to tag the image with the full registry path before pushing -> Option A

4. Quick Check:

   Push needs full registry tag [OK]

Hint: Push needs full registry path tag [OK]

Common Mistakes:

• Trying to pull before push
• Assuming image name syntax is wrong
• Deleting local image before push

5. You want to update your app image in Google Container Registry with a new version. Which sequence of commands correctly tags, pushes, and then pulls the updated image for deployment?

hard

A. docker build myapp:v2 && docker pull gcr.io/my-project/myapp:v2 && docker push gcr.io/my-project/myapp:v2

B. docker pull gcr.io/my-project/myapp:v2 && docker tag myapp:v2 && docker push myapp:v2

C. docker push myapp:v2 && docker tag myapp gcr.io/my-project/myapp:v2 && docker pull myapp:v2

D. docker tag myapp gcr.io/my-project/myapp:v2 && docker push gcr.io/my-project/myapp:v2 && docker pull gcr.io/my-project/myapp:v2

Solution

1. Step 1: Tag the local image with the full registry path

   Use docker tag myapp gcr.io/my-project/myapp:v2 to prepare the image for pushing.

2. Step 2: Push the tagged image to Google Container Registry

   Run docker push gcr.io/my-project/myapp:v2 to upload the image.

3. Step 3: Pull the updated image to confirm availability for deployment

   Use docker pull gcr.io/my-project/myapp:v2 to download the image where needed.

4. Final Answer:

   docker tag myapp gcr.io/my-project/myapp:v2 && docker push gcr.io/my-project/myapp:v2 && docker pull gcr.io/my-project/myapp:v2 -> Option D

5. Quick Check:

   Tag, push, then pull sequence [OK]

Hint: Tag with full path, push, then pull updated image [OK]

Common Mistakes:

• Pushing before tagging with full path
• Pulling before pushing updated image
• Incorrect command order