DCA Exam Dumps : Docker Certified Associate (DCA) Exam

= The command docker service create -name dns-cache -p 53:53 -udp dns-cache will not create a swarm service that only listens on port 53 using the UDP protocol. The reason is that the command has several syntax errors and invalid options. The correct command to create a swarm service that only listens on port 53 using the UDP protocol is docker service create --name dns-cache --publish published=53,target=53,protocol=udp dns-cache12. The command docker service create -name dns-cache -p 53:53 -udp dns-cache has the following problems:

The option -name is not a valid option for docker service create. The valid option for specifying the service name is --name3.

The option -p is not a valid option for docker service create. The valid option for publishing a port for a service is --publish1.

The option -udp is not a valid option for docker service create. The valid option for specifying the protocol for a published port is protocol within the --publish option1.

The argument 53:53 is not a valid argument for docker service create. The argument for docker service create should be the image name for the service, such as dns-cache3. The source and target of the published port should be specified in the --publish option, separated by a comma1.

Therefore, the command docker service create -name dns-cache -p 53:53 -udp dns-cache will not work as intended, and will likely produce an error message or an unexpected result. References:

Use swarm mode routing mesh

Manage swarm service networks

docker service create

= Provisioning a Docker config object for each environment is a way to provision configuration to containers at runtime. Docker configs allow services to adapt their behaviour without the need to rebuild a Docker image. Services can only access configs when explicitly granted by a configs attribute within the services top-level element. As with volumes, configs are mounted as files into a service’s container’s filesystem1. Docker configs are supported on both Linux and Windows services2. References: Docker Documentation, Configs top-level element

The strategy will not successfully accomplish mounting the /data directory on your laptop into a container. The containers. Mounts. hostBinding: /data is not a valid syntax for specifying a bind mount in a Kubernetes container specification. According to the Kubernetes documentation), the correct way to mount a host directory into a container is to use a hostPath volume, which takes a path parameter that specifies the location on the host. For example, to mount the /data directory on your laptop into a container at /var/data, you can use the following YAML snippet:

spec:

containers:

-name:my-container

image:my-image

volumeMounts:

-name:data-volume

mountPath:/var/data

volumes:

-name:data-volume

hostPath:

path:/data

Volumes), Use bind mounts)