Mirantis Mirantis Certifications DCA Questions & Answers

• Question 111:

  Will this sequence of steps completely delete an image from disk in the Docker Trusted Registry? Solution: Delete the image and run garbage collection on the Docker Trusted Registry.

  A. Yes

  B. No

  Correct Answer: A

  Deleting the image and running garbage collection on the Docker Trusted Registry will completely delete the image from disk. According to the official documentation, this is the recommended way to remove images and reclaim disk space.

• Question 112:

  Which of the following commands starts a Redis container and configures it to always restart unless it is explicitly stopped or Docker is restarted?

  A. 'docker run -d --restart-policy unless-stopped redis'

  B. 'docker run -d --restart omit-stopped redis'

  C. 'docker run -d --restart unless-stopped redis'

  D. 'docker run -d --failure omit-stopped redis'

  Correct Answer: C

• Question 113:

  You want to create a container that is reachable from its host's network. Does this action accomplish this? Solution: Use network attach to access the containers on the bridge network

  A. Yes

  B. No

  Correct Answer: B

  Using network attach to access the containers on the bridge network does not make the container reachable from its host's network. The network attach option connects a running container to another network, but it does not expose any ports to the host. To make a container reachable from its host's network, you need to use either EXPOSE or --publish to access the containers on the bridge network.

• Question 114:

  Will this action upgrade Docker Engine CE to Docker Engine EE? Solution: Delete '/var/lib/docker' directory.

  A. Yes

  B. No

  Correct Answer: B

  Deleting `/var/lib/docker' directory does not upgrade Docker Engine CE to Docker Engine EE. The `/var/lib/docker' directory is where Docker stores all its data and metadata related to containers, images, volumes, networks, etc. Deleting this directory will remove all your Docker data and configurations from your system, but it will not change your Docker version or edition. To upgrade Docker Engine CE to Docker Engine EE, you need to uninstall `docker-ce' package before installing `docker-ee' package.

• Question 115:

  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.

  A. Yes

  B. No

  Correct Answer: A

  Provisioning a Docker config object for each environment is a way to provision configuration to containers at runtime. A Docker config object is a file that contains configuration data for an application or service. It can be created using the docker config create command and then attached to a service using the --config flag of the docker service create or update command. This allows different configurations to be applied to different environments without changing the image or the code of the application.

• Question 116:

  Is this a type of Linux kernel namespace that provides container isolation? Solution: Authentication

  A. Yes

  B. No

  Correct Answer: B

  Authentication is not a type of Linux kernel namespace that provides container isolation. Namespaces are a Linux kernel feature that provide isolation and virtualization of system resources for processes. They can be used to create isolated environments for containers that have their own view of system resources, such as process IDs, user IDs, network interfaces, etc. However, there is no authentication namespace in Linux. The types of namespaces that exist are mount (mnt), process ID (pid), network (net), interprocess communication (ipc), user ID (user), control group (cgroup), time (time), and user namespace (uts).

• Question 117:

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

  A. Yes

  B. No

  Correct Answer: B

  Using docker container logs nginx --volumes does not display a list of volumes for a specific container. The docker container logs command shows information about the logs of a container. The --volumes flag is not a valid option for this command and will cause an error. To display a list of volumes for a specific container, you need to use docker container inspect nginx --format `{{ .Mounts }}'.

• Question 118:

  Some Docker images take time to build through a Continuous Integration environment. You want to speed up builds and take advantage of build caching. Where should the most frequently changed part of a Docker image be placed in a Dockerfile?

  A. at the bottom of the Dockerfile

  B. after the FROM directive

  C. at the top of the Dockerfile

  D. in the ENTRYPOINT directive

  Correct Answer: A

• Question 119:

  What is the docker command to find the current logging driver for a running container?

  A. docker stats

  B. docker info

  C. docker config

  D. docker inspect

  Correct Answer: D

• Question 120:

  The Kubernetes yaml shown below describes a networkPolicy.

  

  Will the networkPolicy BLOCK this traffic?

  Solution: a request issued from a pod lacking the tier: api label, to a pod bearing the tier:

  backend label

  A. Yes

  B. No

  Correct Answer: B

  The networkPolicy will not block this traffic because it does not apply to pods that have the tier: backend label. The networkPolicy only applies to pods that have the tier: frontend label, as specified by the podSelector field. Pods that have the tier: backend label are not affected by this networkPolicy and can receive traffic from any source.