Docker Interview Questions and Answer Part – 4

Which of the following will display the specific command that created each layer in an image?

• docker search imagename
• docker images -t imagename
• docker history imagename (Ans)
• docker build -th imagename

You would prepare an image called hello-world for uploading to a local Docker Registry using which of the following commands?

• docker tag hello-world localhost/hello-world:latest
• docker -tag 127.0.0.1/hello-world:latest
• docker -t hello-world localhost:5000/hello-world:latest
• docker tag hello-world localhost:5000/hello-world:latest (Ans)

Where are the image files stored on a Linux machine running a package-based Docker Registry?

• /var/lib/docker/docker-registry/docker/registry/v2/repositories (Ans)
• /var/lib/docker/docker-registry/docker/registry/v2/_catalog
• /var/lib/docker/volumes//_data/docker/registry/v2/repositories/
• /var/lib/docker/docker-registry

Which of these commands will return a list of images currently stored in a Docker Registry?

• curl 192.168.1.17:5000/v2/_data
• curl 192.168.1.17:5000/v2/_catalog (Ans)
• docker images
• docker registry ls

To add encryption using a self-signed certificate to your Docker Registry infrastructure, to which directory must the certificate be copied (assuming your domain is domain.com)?

• /etc/docker/cert.d/domain.com:5000/
• /var/lib/docker/certs.d/domain.com:5000/
• /etc/docker/certs.d/domain.com:5000/ (Ans)
• /etc/docker/certs.d/domain.com/

How do you temporarily enable Docker Content Trust on your local machine to take advantage of digitally signed images?

• export $DOCKER_CONTENT_TRUST=0
• export DOCKER_CONTENT_TRUST=1 (Ans)
• echo $DOCKER_CONTENT_TRUST=1
• echo DOCKER_CONTENT_TRUST=1 >> /etc/profile

Which of the following will upload a new stack to your Docker Cloud account?

• docker-cloud stack create -f dockerfile
• docker-cloud stack create docker-cloud.yml
• docker stack create -f docker-cloud.yml
• docker-cloud stack create -f docker-cloud.yml (Ans)

Docker Engine is:

• An online Docker image repository
• An online Docker administration interface
• The locally installed runtime through which you administrate Docker containers (Ans)
• A local Docker image repository

Docker Trusted Registry is:

• An open source tool for securing the infrastructure on which Docker Engine runs
• An open source tool for coordinating Docker container clusters
• A web-based, commercial, hosted image management tool (Ans)
• A local, commercial image management tool

A Docker container will run faster when its image is properly optimized. Which of the following will have the greatest positive impact on speed?

• Build the image using as few layers as possible. (Ans)
• Always base your images on the latest operating system version available.
• Build the image using a Dockerfile rather than from a running container.
• Always be consistent in the software package versions you choose for your image layers

Which of the following commands will successfully build an image with the name “myimage”?

• docker build -t myimage . (Ans)
• docker build –tag-image myimage
• docker build -t myimage
• docker build -n myimage .

What is accomplished by running the following command?
docker run -p 5000:5000 registry:latest

• Only if the Docker Registry image has already been pulled will it be run, exposing port 5000.
• The Docker Registry image will (if necessary) be pulled and then run, exposing port 5000. (Ans)
• Docker Engine will run a “hot update” on the live Registry image.
• The Docker Registry image will be pulled from Docker Hub using port 5000.

Which of these is the correct command to display a list images currently stored in a Docker Registry using a self-signed certificate?

• curl -i https://192.168.1.16:5000/v2/_data
• curl -i https://192.168.1.16:5000/v2/_catalog
• curl –insecure http://192.168.1.16:5000/v2/_catalog
• curl –insecure https://192.168.1.16:5000/v2/_catalog (Ans)

Rajesh Kumar

I’m Rajesh Kumar, a DevOps, SRE, DevSecOps, Cloud, and Platform Engineering expert passionate about sharing practical knowledge, real-world experiences, and industry best practices. I have worked at Cotocus and regularly write about technology, travel, investing, health, product reviews, and digital marketing through my various platforms.

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