Docker DCA Online Practice Questions and Exam Preparation

Docker DCA Online Questions & Answers

• Question 21:

  Will a DTR security scan detect this?

  Solution: private keys copied to the image

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  A DTR security scan does not detect private keys copied to the image. 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 private keys or other sensitive data that may be accidentally or intentionally copied to the image. To avoid copying private keys to the image, you should use Docker secrets or other secure mechanisms to manage your credentials.

• Question 22:

  What service mode is used to deploy a single task of a service to each node?

  A. replicated
  B. spread
  C. universal
  D. distributed
  E. global
  E. global

• Question 23:

  One of several containers in a pod is marked as unhealthy after failing its livenessProbe many times. Is this the action taken by the orchestrator to fix the unhealthy container? Solution: The controller managing the pod is autoscaled back to delete the unhealthy pod and alleviate load.

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  The controller managing the pod is not autoscaled back to delete the unhealthy pod and alleviate load, because this is not how Kubernetes handles pod failures. According to the official documentation, Kubernetes will try to maintain the desired number of pods for each controller, and will not scale down or up based on pod health.

• Question 24:

  Is this the purpose of Docker Content Trust?

  Solution: Enable mutual TLS between the Docker client and server.

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  Enabling mutual TLS between the Docker client and server is not the purpose of Docker Content Trust. According to the official documentation, the purpose of Docker Content Trust is to verify the integrity and publisher of all data received from a registry over any channel.

• Question 25:

  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: Create a PersistentVolume with storageciass: "" and hostPath: /data, and a persistentVolumeClaim requesting this PV. Then use that PVC to populate a volume in a pod

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  Creating a PersistentVolume with storageClass: "" and hostPath: /data, and a persistentVolumeClaim requesting this PV, and then using that PVC to populate a volume in a pod is not a strategy that successfully accomplishes this. A PersistentVolume is an API object that represents a piece of storage in the cluster that has been provisioned by an administrator. A PersistentVolumeClaim is a request for storage by a user. A hostPath PersistentVolume uses a file or directory on the node to emulate network-attached storage. However, this type of volume only works on a single node cluster, and it does not work on Windows nodes. Therefore, it cannot be used to mount the /data directory on your laptop into a container.

• Question 26:

  Seven managers are in a swarm cluster.

  Is this how should they be distributed across three datacenters or availability zones?

  Solution: 3-2-2

  A. Yes
  B. No
  A. Yes

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  Explanation/Reference:

  This is how they should be distributed across three datacenters or availability zones, because having an even distribution of managers across datacenters or availability zones ensures that the swarm can survive the loss of any one datacenter or availability zone and maintain quorum. According to the official documentation, managers should be distributed evenly across datacenters or availability zones to ensure that the swarm can survive the loss of any one datacenter or availability zone.

• Question 27:

  Does this command create a swarm service that only listens on port 53 using the UDP protocol? Solution. `docker service create -name dns-cache -p 53:53 -udp dns-cache'

  A. Yes
  B. No
  A. Yes

• Question 28:

  A users attempts to set the system time from inside a Docker container are unsuccessful. Could this be blocking this operation? Solution: inter-process communication

  A. Yes
  B. No
  B. No

• Question 29:

  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: Mirror the engineering/api repository to one of the user's own private repositories.

  A. Yes
  B. No
  B. No

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  Explanation/Reference:

  Mirroring the engineering/api repository to one of the user's own private repositories does not grant them read/write access to the engineering/api repository. Mirroring is a feature that allows you to automatically replicate images from one repository to another, either within the same DTR or across different DTRs. Mirroring does not change the permissions or access levels of the source or destination repositories. It only copies the images and tags from one repository to another. To grant a user read/write access to the engineering/api repository, you need to add them as a collaborator with read/write role on that repository, or add them to a team that has read/write role on that repository.

• Question 30:

  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 the user directly to the list of users with read/write access under the repository's Permissions tab.

  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 a user directly to the list of users with read/write access under the repository's Permissions tab is one way to grant permissions to a user in DTR. According to the official documentation, this is an example of using fine-grained permissions for a repository.