DCA Online Practice Questions and Answers

Correct Answer: AC

Correct Answer: A

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

Correct Answer: B

mnt is not 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, mnt is one of the namespaces that are enabled by default when using namespaces for isolation.

Correct Answer: A

Using `docker node ls' lists all nodes in a swarm cluster from the command line. The docker node command is used to manage nodes in a swarm. The docker node ls subcommand displays information about the nodes in the swarm, such as their ID, hostname, status, availability, and role.

Correct Answer: A

Correct Answer: A

This does describe the role of Control Groups (cgroups) when used with a Docker container, because accounting and limiting of resources is one of the main functions of cgroups. According to the official documentation, cgroups are a Linux kernel feature that limits and isolates the resource usage of a group of processes, such as CPU, memory, disk I/O, network, etc. Docker can use cgroups to share available hardware resources to containers and optionally enforce limits and constraints.

Correct Answer: B

Using kubectl get deployment api does not display the events table for this object. The kubectl get command shows basic information about one or more resources, such as their name, age, status, etc. It does not show the events table, which is a list of events that occurred on the resource, such as creation, update, scaling, etc. To see the events table for this object, you need to use kubectl describe deployment api.

Correct Answer: A

Running docker engine activate does upgrade Docker Engine CE to Docker Engine EE. The docker engine activate command is a convenience script that automates the process of uninstalling Docker Engine CE and installing Docker Engine EE on supported platforms. It requires an activation token or license file that can be obtained from Docker Hub or Docker Store.

Correct Answer: B

Environment variables cannot be used to schedule containers to meet the security policy requirements. Environment variables are key-value pairs that can be passed to containers when they are created or run. Environment variables can be used to configure the behavior of the containerized application or provide runtime information, such as database credentials, API keys, etc. Environment variables do not affect how containers are scheduled on nodes in a swarm mode cluster.

Correct Answer: B

An instance of the Docker CLI connected to the swarm does not describe a node in the context of a swarm mode cluster. A node is a physical or virtual machine that runs the Docker Engine and participates in the swarm. A node can have one

of two roles:

manager or worker. Manager nodes maintain the cluster state and orchestrate tasks. Worker nodes execute tasks assigned by manager nodes. An instance of the Docker CLI connected to the swarm is a client that can interact with the

swarm using commands such as docker service, docker node, docker stack, etc. A client can connect to any manager node in the swarm using the --host or -H flag.