Docker DCA Online Practice Questions and Exam Preparation

Docker DCA Online Questions & Answers

• Question 71:

  Which of the following is NOT backed up when performing a Docker Trusted backup operation?

  A. Access control to repos and images
  B. Repository metadata
  C. Image blobs
  D. DTR configurations
  C. Image blobs

• Question 72:

  Is this a Linux kernel namespace that is disabled by default and must be enabled at Docker engine runtime to be used? Solution: user

  A. Yes
  B. No
  A. Yes

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  Explanation/Reference:

  user is a Linux kernel namespace that is disabled by default and must be enabled at Docker engine runtime to be used. According to the official documentation, user namespace support must be explicitly enabled in two ways: The dockerd daemon must be started with --userns-remap flag. The user or group specified for --userns-remap must have subordinate user and group IDs allocated in /etc/subuid and /etc/subgid files

• Question 73:

  During development of an application meant to be orchestrated by Kubernetes, you want to mount the /data directory on your laptop into a container.

  Will this strategy successfully accomplish this?

  Solution: Set containers. Mounts. hostBinding: /data in the container's specification.

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  This strategy does not successfully mount the /data directory on your laptop into a container. Setting containers.mounts.hostBinding to /data in the container's specification is not a valid way to mount a host directory into a container in

  Kubernetes. Kubernetes does not support mounting arbitrary host directories into containers, as this would break the portability and isolation of pods across different nodes. To mount a host directory into a container in Kubernetes, you need

  to use one of the following methods:

  Use hostPath volume, which allows you to mount a file or directory from the host node's filesystem into your pod.

  Use local volume, which allows you to mount local storage devices such as disks or partitions into your pod.

  Use persistentVolume and persistentVolumeClaim with hostPath or local volume as storage class, which allows you to abstract the details of how storage is provided from how it is consumed.

• Question 74:

  Does this command display all the pods in the cluster that are labeled as 'env: development'?

  Solution: 'kubectl get pods --all-namespaces -I env=development'

  A. Yes
  B. No
  A. Yes

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  Explanation/Reference:

  This command does display all the pods in the cluster that are labeled as env: development. The kubectl get pods command shows information about all the pods in a cluster or a specific namespace. The --all-namespaces flag tells kubectl to include pods from all namespaces in the output. The -l flag tells kubectl to filter the output by a label selector, which is an expression that matches labels to values. The label selector `env in (development)' matches pods that have a label env with a value development. Therefore, this command displays all the pods in the cluster that are labeled as env: development.

• Question 75:

  In Docker Trusted Registry, how would a user prevent an image, for example 'nginx:latest' from being overwritten by another user with push access to the repository?

  A. Tag the image with 'nginx:immutable'
  B. Remove push access from all other users.
  C. Use the DTR web UI to make the tag immutable.
  D. Keep a backup copy of the image on another repository.
  C. Use the DTR web UI to make the tag immutable.

• Question 76:

  You are troubleshooting a Kubernetes deployment called api, and want to see the events table for this object.

  Does this command display it?

  Solution: kubectl describe deployment api

  A. Yes
  B. No
  A. Yes

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  Explanation/Reference:

  Using kubectl describe deployment api displays the events table for this object. The kubectl describe command shows detailed information about a resource, including its status and events. This command can be used to troubleshoot a deployment that is not working as expected

• Question 77:

  You want to provide a configuration file to a container at runtime. Does this set of Kubernetes tools and steps accomplish this?

  Solution: Turn the configuration file into a configMap object, use it to populate a volume associated with the pod, and mount that file from the volume to the appropriate container and path.

  A. Yes
  B. No
  A. Yes

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  Explanation/Reference:

  This set of Kubernetes tools and steps accomplishes this, because it follows the recommended way of providing a configuration file to a container at runtime using a configMap object. According to the official documentation, this method allows you to decouple configuration artifacts from image content and update them without restarting containers.

• Question 78:

  When seven managers are in a swarm cluster how would they be distributed across three datacenters or availability zones?

  A. 5-1-1
  B. 3-2-2
  C. 3-3-1
  D. 4-2-1
  B. 3-2-2

• Question 79:

  You add a new user to the engineering organization in DTR.

  Will this action grant them read/write access to the engineering/api repository?

  Solution: Add them to a team in the engineering organization that has read/write access to the engineering/api repository.

  A. Yes
  B. No
  A. Yes

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  Explanation/Reference:

  This action will grant them read/write access to the engineering/api repository, because adding them to a team in the engineering organization that has read/write access to the engineering/api repository is another way to grant permissions to a user in DTR. According to the official documentation, this is an example of using teams and organizations for managing permissions.

• Question 80:

  A user is having problems running Docker. Which of the following will start Docker in debug mode?

  A. Set the debug key to true in the 'daemon.json' file.
  B. Start the 'dockerd' process manually with the '--logging' flag set to debug
  C. Set the logging key to debug in the 'daemon.json' file.
  D. Start the 'dockerd' process manually with the '--raw-logs' flag set to debug
  A. Set the debug key to true in the 'daemon.json' file.