Docker DCA Online Practice Questions and Exam Preparation

Docker DCA Online Questions & Answers

• Question 131:

  Your organization has a centralized logging solution, such as Splunk.

  Will this configure a Docker container to export container logs to the logging solution?

  Solution: docker system events --filter splunk

  A. Yes
  B. No
  B. No

• Question 132:

  You want to create a container that is reachable from its host's network.

  Does this action accomplish this?

  Solution: Use --link to access the container on the bridge network.

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  Using either EXPOSE or --publish to access the container on the bridge network does not create a container that is reachable from its host's network. EXPOSE and --publish are options that specify which ports on the container should be exposed or published to the outside world. They do not affect which network the container is connected to. By default, Docker creates and connects containers to a bridge network, which is an internal network that isolates containers from each other and from the host. To create a container that is reachable from its host's network, you need to use --network host option, which connects the container to the host's network stack.

• Question 133:

  Will a DTR security scan detect this?

  Solution: image configuration poor practices, such as exposed ports or inclusion of compilers in production images

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  A DTR security scan does not detect image configuration poor practices, such as exposed ports or inclusion of compilers in production images. A DTR security scan is a feature that scans images for known vulnerabilities in the software packages or dependencies that are installed in the image. A DTR security scan does not check for image configuration poor practices, such as exposing unnecessary ports or including unnecessary tools in production images. To avoid image configuration poor practices, you should follow the Dockerfile best practices and use multi-stage builds to optimize your images.

• Question 134:

  Will this command ensure that overlay traffic between service tasks is encrypted?

  Solution: docker network create -d overlay --secure

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  Using docker network create -d overlay --secure does not ensure that overlay traffic between service tasks is encrypted. The --secure flag is not a valid option for this command and will cause an error. To ensure that overlay traffic between service tasks is encrypted, you need to use --opt encrypted flag instead. This flag enables IPsec encryption at the level of the vxlan overlay driver.

• Question 135:

  You have deployed a service to swarm. Which command uses the Docker CLI to set the number of tasks of the services to 5? (choose 2)

  A. 'docker service update --replicas=5 '
  B. 'docker replica update =5'
  C. 'docker update service =5'
  D. 'docker service replicas =5'
  E. 'docker service scale = 5''
  A. 'docker service update --replicas=5 '
  E. 'docker service scale = 5''

• Question 136:

  Will this command display a list of volumes for a specific container? Solution: docker volume inspect nginx'

  A. Yes
  B. No
  B. No

• Question 137:

  You have created a Docker bridge network on a host with three containers attached, how do you make this containers accessible outside of the host?

  A. Use network attach to access the containers on the bridge network
  B. Use either EXPOSE or --publish to access the containers on the bridge network
  C. Use network connect to access the containers on the bridge network
  D. Use --link to access the containers on the bridge network Correct
  B. Use either EXPOSE or --publish to access the containers on the bridge network

• Question 138:

  Are these conditions sufficient for Kubernetes to dynamically provision a persistentVolume, assuming there are no limitations on the amount and type of available external storage? Solution: A default provisioner is specified, and subsequently a persistentVolumeClaim is created.

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  These conditions are not sufficient for Kubernetes to dynamically provision a persistentVolume, because a default provisioner is not enough to determine how to create a persistentVolume. According to the official documentation, you also need to specify a default storageClass or annotate your persistentVolumeClaim with a specific storageClass name.

• Question 139:

  Will this sequence of steps completely delete an image from disk in the Docker Trusted Registry? Solution: Delete the image and delete the image repository from Docker Trusted Registry

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  Deleting the image and deleting the image repository from Docker Trusted Registry (DTR) does not completely delete an image from disk in DTR. Deleting an image only removes its tag and association with a repository, but does not delete its underlying layers from disk. Deleting a repository only removes its metadata and tags, but does not delete its underlying layers from disk either. To completely delete an image from disk in DTR, you need to run a garbage collection job after deleting the image or the repository. A garbage collection job scans the DTR storage and removes any unused layers that are not referenced by any images or repositories.

• Question 140:

  A container named "analytics" that stores results in a volume called "data" was created.

  docker run -d --name=analytics -v data:/data app1

  How are the results accessed in "data" with another container called "app2"?

  A. docker run -d --name=reports --volume=data app2
  B. docker run -d --name=reports --volumes-from=analytics app2
  C. docker run -d --name=reports --volume=app1 app2
  D. docker run -d --name=reports --mount=app1 app2
  B. docker run -d --name=reports --volumes-from=analytics app2