Limited-Time Offer: Enjoy 60% Savings! - Ends In 0d 00h 00m 00s Coupon code: 60OFF
Welcome to QA4Exam
Logo

- Trusted Worldwide Questions & Answers
Mail Us support@qa4exam.com
0
Menu

Most Recent Docker DCA Exam Questions & Answers


Prepare for the Docker Certified Associate Exam exam with our extensive collection of questions and answers. These practice Q&A are updated according to the latest syllabus, providing you with the tools needed to review and test your knowledge.

QA4Exam focus on the latest syllabus and exam objectives, our practice Q&A are designed to help you identify key topics and solidify your understanding. By focusing on the core curriculum, These Questions & Answers helps you cover all the essential topics, ensuring you're well-prepared for every section of the exam. Each question comes with a detailed explanation, offering valuable insights and helping you to learn from your mistakes. Whether you're looking to assess your progress or dive deeper into complex topics, our updated Q&A will provide the support you need to confidently approach the Docker DCA exam and achieve success.

The questions for DCA were last updated on Jan 17, 2025.
  • Viewing page 1 out of 37 pages.
  • Viewing questions 1-5 out of 183 questions
Get All 183 Questions & Answers
Question No. 1

An application image runs in multiple environments, with each environment using different certificates and ports.

Is this a way to provision configuration to containers at runtime?

Solution: Provision a Docker config object for each environment.

Show Answer Hide Answer
Correct Answer: A

= Provisioning a Docker config object for each environment is a way to provision configuration to containers at runtime. Docker configs allow services to adapt their behaviour without the need to rebuild a Docker image. Services can only access configs when explicitly granted by a configs attribute within the services top-level element.As with volumes, configs are mounted as files into a service's container's filesystem1.Docker configs are supported on both Linux and Windows services2.Reference:Docker Documentation,Configs top-level element


Question No. 2

Is this an advantage of multi-stage builds?

Solution: faster image builds by allowing parallel execution of Docker builds

Show Answer Hide Answer
Correct Answer: B

= Simultaneously creating and tagging multiple images is not an advantage of multi-stage builds.Multi-stage builds are a feature that allows you to use multiple FROM statements in your Dockerfile, each starting a new stage of the build1. You can selectively copy artifacts from one stage to another, leaving behind everything you don't want in the final image.This helps you to optimize the size and security of your images, as well as to simplify your build process12. However, multi-stage builds do not create or tag multiple images at once.Each Dockerfile produces one final image, which is the result of the last stage in the Dockerfile1.If you want to create and tag multiple images from a single Dockerfile, you need to use the--targetoption with thedocker buildcommand, and specify the name of the stage you want to build and tag3.Reference:

Multi-stage builds | Docker Docs

What Are Multi-Stage Docker Builds? - How-To Geek

Stop at a specific build stage | Docker Docs


Question No. 3

You configure a local Docker engine to enforce content trust by setting the environment variable

DOCKER_CONTENT_TRUST=1.

If myorg/myimage: 1.0 is unsigned, does Docker block this command?

Solution: docker image import myorg/myimage:1.0

Show Answer Hide Answer
Correct Answer: A

Docker Content Trust (DCT) is a feature that allows users to verify the integrity and publisher of container images they pull or deploy from a registry server, signed on a Notary server1. DCT is enabled by setting the environment variable DOCKER_CONTENT_TRUST=1 on the Docker client.When DCT is enabled, the Docker client will only pull, run, or build images that have valid signatures for a specific tag2.However, DCT does not apply to the docker image import command, which allows users to import an image or a tarball with a repository and tag from a file or STDIN3. Therefore, if myorg/myimage:1.0 is unsigned, Docker will not block the docker image import <tarball> myorg/myimage:1.0 command, even if DCT is enabled. This is because the docker image import command does not interact with a registry or a Notary server, and thus does not perform any signature verification. However, this also means that the imported image will not have any trust data associated with it, and it will not be possible to push it to a registry with DCT enabled, unless it is signed with a valid key.Reference:

Content trust in Docker

Automation with content trust

[docker image import]

[Content trust and image tags]


Question No. 4

Will this command mount the host's '/data* directory to the ubuntu container in read-only mode?

Solution. 'docker run -add-volume /data /mydata -read-only ubuntu'

Show Answer Hide Answer
Correct Answer: B

= The commanddocker run -add-volume /data /mydata -read-only ubuntuwill not mount the host's/datadirectory to the ubuntu container in read-only mode. The reason is that the command has several syntax errors and invalid options.The correct command to mount a host directory to a container in read-only mode isdocker run --mount type=bind,source=/data,target=/mydata,readonly ubuntu12. The commanddocker run -add-volume /data /mydata -read-only ubuntuhas the following problems:

The option-add-volumeis not a valid option fordocker run.The valid options for mounting a volume or a bind mount are--mountor-v12.

The option-read-onlyis not a valid option fordocker run.The valid option for making the container's root filesystem read-only is--read-only3.However, this option will not affect the mounted volumes or bind mounts, which have their ownreadonlyoption12.

The argument/data /mydatais not a valid argument fordocker run.The argument fordocker runshould be the command to run inside the container, such asbashorping4.The source and target of the volume or bind mount should be specified in the--mountor-voption, separated by a colon12.

Therefore, the commanddocker run -add-volume /data /mydata -read-only ubuntuwill not work as intended, and will likely produce an error message or an unexpected result.Reference:

Use bind mounts

Use volumes

docker run

Docker run reference


Question No. 5

The Kubernetes yaml shown below describes a clusterIP service.

Is this a correct statement about how this service routes requests?

Solution: Traffic sent to the IP of this service on port 80 will be routed to port 8080 in a random pod with the label app:

nginx.

Show Answer Hide Answer
Correct Answer: B

The statement is not entirely correct. In Kubernetes, a service of type ClusterIP routes traffic sent to its IP address to the pods selected by its label selector1. However, the port to which the traffic is routed in the pod is determined by the targetPort specified in the service definition1. If targetPort is not specified, it defaults to being the same as the port field1. In the provided YAML snippet, there is no targetPort specified for port 80, so we cannot confirm that the traffic will be routed to port 8080 in the pod. Therefore, without additional information about the pod configuration, we cannot verify the provided solution statement1.


Unlock All Questions for Docker DCA Exam

Full Exam Access, Actual Exam Questions, Validated Answers, Anytime Anywhere, No Download Limits, No Practice Limits

Get All 183 Questions & Answers
Explore Other Docker Exams