Mirantis Mirantis Certifications DCA Questions & Answers

• Question 81:

  Does this command display all the pods in the cluster that are labeled as 'env: development'? Solution: 'kubectl get pods --all-namespaces -label env=development'

  A. Yes

  B. No

  Correct Answer: B

• Question 82:

  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 8080 will be routed to port 80 in a random pod with the label aPP: nginx.

  A. Yes

  B. No

  Correct Answer: A

  Traffic sent to the IP of this service on port 8080 will be routed to port 80 in a random pod with the label app: nginx is a correct statement about how this service routes requests. A clusterIP service is a type of service that exposes an internal IP address that is only reachable within the cluster. A clusterIP service routes requests to pods based on their labels and selectors. In this case, the service has a selector app: nginx, which means it will route requests to any pod that has the label app: nginx. The service also has a port mapping from 8080 to 80, which means it will forward requests from port 8080 on the service IP to port 80 on the pod IP. The service will use a round-robin algorithm to distribute requests among the pods that match the selector.

• Question 83:

  Is this statement correct?

  Solution: A Dockerfile provides instructions for building a Docker image

  A. Yes

  B. No

  Correct Answer: A

  This statement is correct. A Dockerfile provides instructions for building a Docker image. A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image. Using docker build, you can create an automated build that executes several command-line instructions in succession.

• Question 84:

  Can this set of commands identify the published port(s) for a container? Solution: docker container inspect', 'docker port'

  A. Yes

  B. No

  Correct Answer: A

  This set of commands can identify the published port(s) for a container, because docker container inspect can show the port mappings for a container and docker port can list the public port that is NAT-ed to the private port. According to the official documentation, these commands can be used to find the exposed ports for a container.

• Question 85:

  A company's security policy specifies that development and production containers must run on separate nodes in a given Swarm cluster.

  Can this be used to schedule containers to meet the security policy requirements?

  Solution: resource reservation

  A. Yes

  B. No

  Correct Answer: B

  Resource reservation cannot be used to schedule containers to meet the security policy requirements, because resource reservation only affects the available resources on a node and does not restrict which containers can run on which nodes. According to the official documentation, resource reservation is used to ensure that a service has enough resources to run. References: https://docs.docker.com/engine/swarm/services/#reserve-memory-or-cpus-for- a-service

• Question 86:

  Which of the following is true about overlay networks?

  A. Overlay networks are created only on the manager node that you created the overlay networking on

  B. Overlay networks are created on all cluster nodes when you create the overlay network.

  C. Overlay networks are first created on the manager nodes. Then they are created on the worker nodes once a task is scheduled on the specific worker node.

  D. Overlay networks are only created on the manager nodes.

  Correct Answer: B

• Question 87:

  Will this command list all nodes in a swarm cluster from the command line? Solution: 'docker swarm nodes'

  A. Yes

  B. No

  Correct Answer: B

  This command does not list all nodes in a swarm cluster from the command line. The docker swarm command manages swarm operations, such as initializing or joining a swarm, updating the swarm configuration, etc. It does not show information about nodes or services. To list all nodes in a swarm cluster from the command line, you need to use docker node ls command. This command shows information about all the nodes that are part of the swarm, such as their ID, hostname, status, availability, etc.

• Question 88:

  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 any pod with the label app: nginx on port 8080 will be forwarded to port 80 in that pod.

  A. Yes

  B. No

  Correct Answer: B

  Traffic sent to the IP of any pod with the label app: nginx on port 8080 will be forwarded to port 80 in that pod is not a correct statement about how this service routes requests. A clusterIP service does not route requests based on the pod IP, but on the service IP. A clusterIP service also does not forward requests from one port on the pod IP to another port on the same pod IP, but from one port on the service IP to another port on the pod IP. Therefore, this statement is incorrect and does not describe how this service routes requests. References: https://kubernetes.io/docs/concepts/services- networking/service/#defining-a-service, https://kubernetes.io/docs/concepts/services- networking/service/#virtual-ips-andservice-proxies

• Question 89:

  You set up an automatic pruning policy on a DTR repository to prune all images using Apache licenses. What effect does this have on images in this repository?

  A. Matching images are untagged once they are older than the pruning threshold set in the repository's Settings tab.

  B. Matching Images are untagged during the next prune job.

  C. Matching images are deleted during the next prune Job.

  D. Matching images are untagged during the next prune job, and subsequently deleted once they are older than the pruning threshold set in the repository's Settings tab.

  Correct Answer: A

• Question 90:

  Will this command ensure that overlay traffic between service tasks is encrypted? Solution: docker service create --network --encrypted

  A. Yes

  B. No

  Correct Answer: B

  This command will not ensure that overlay traffic between service tasks is encrypted, because it uses an invalid option for enabling encryption and an incomplete option for specifying the network. According to the official documentation, there is no such option as --encrypted for the docker service create command. The correct option to use is - -network where is an existing overlay network that was created with encryption enabled.