Free Docker DCA Exam Dumps

= The commanddocker service create -name dns-cache -p 53:53 -udp dns-cachewill 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 isdocker service create --name dns-cache --publish published=53,target=53,protocol=udp dns-cache12. The commanddocker service create -name dns-cache -p 53:53 -udp dns-cachehas the following problems:

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

The option-pis not a valid option fordocker service create.The valid option for publishing a port for a service is--publish1.

The option-udpis not a valid option fordocker service create.The valid option for specifying the protocol for a published port isprotocolwithin the--publishoption1.

The argument53:53is not a valid argument fordocker service create.The argument fordocker service createshould be the image name for the service, such asdns-cache3.The source and target of the published port should be specified in the--publishoption, separated by a comma1.

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

Use swarm mode routing mesh

Manage swarm service networks

docker service create

The sequence of steps willnotcompletely delete an image from disk in the Docker Trusted Registry.Deleting an image and deleting an image repository from the Docker Trusted Registry will only remove the references to the image, but not the actual image data on the disk1.To completely delete an image from disk, you need to run the garbage collection command on the registry server, which will delete any unreferenced blobs2.The garbage collection command isbin/registry garbage-collect /path/to/config.yml3.Reference: Deleting an image), Garbage collection), Running garbage collection)

While creating a Dockerfile for each environment is a possible solution, it is not the most efficient or scalable way to provision configuration to containers at runtime. Docker provides several mechanisms to inject configuration into containers at runtime, such as environment variables, command line arguments, Docker secrets for sensitive data, or even configuration files mounted as volumes. These methods allow the same Docker image to be used across multiple environments, promoting immutability and consistency across your deployments. Creating a separate Dockerfile for each environment would mean maintaining multiple versions of the Dockerfile, which could lead to inconsistencies and is generally not a recommended practice.