Docker Certified Associate (DCA) Practice Exams Set 21

Which command is used to force a full stack trace to be logged?


Options are :

  • sudo kill -trace $(pidof dockerd)
  • sudo kill -SIGUSR1 $(pidof dockerd)
  • sudo strace $(pidof dockerd)
  • sudo trace -SIGUSR1 $(pidof dockerd)

Answer : sudo kill -SIGUSR1 $(pidof dockerd)

Which environment variable needs to be set in order to enable DCT on a per-shell basis?


Options are :

  • DCT_ENABLED
  • DOCKER_CONTENT_TRUST
  • DOCKER_CONTENT_TRUST_ON
  • DCT_ON

Answer : DOCKER_CONTENT_TRUST

Which flag of 'docker swarm init' enables autolocking of swarm manager nodes when Docker restarts?


Options are :

  • --restart-autolock
  • --autolock
  • --restartlock
  • -al

Answer : --autolock

Docker Certified Associate (DCA) Practice Exams Set 8

Which of the following manager node failure scenarios will be handled without downtime? (select two)


Options are :

  • A five-manager swarm tolerates a maximum simultaneous loss of three manager nodes.
  • A three-manager swarm tolerates a maximum loss of one manager.
  • A five-manager swarm tolerates a maximum simultaneous loss of two manager nodes.
  • A seven-manager swarm tolerates a maximum simultaneous loss of four manager nodes.

Answer : A three-manager swarm tolerates a maximum loss of one manager. A five-manager swarm tolerates a maximum simultaneous loss of two manager nodes.

What is the only instruction that may precede FROM in the Dockerfile?


Options are :

  • ARG
  • RUN
  • CMD
  • IMPORT

Answer : ARG

Which instruction defines a variable that users can pass at build-time?


Options are :

  • CMD
  • RUN
  • IMPORT
  • ARG

Answer : ARG

Docker Certified Associate (DCA) Practice Exams Set 20

If a tasks fails during initialization it reverts to its previous state


Options are :

  • FALSE
  • TRUE

Answer : FALSE

What mechanism allows you to organize your images, record licensing information, annotate relationships between containers, volumes, and networks, etc?


Options are :

  • Config files
  • Flags
  • Tags
  • Labels

Answer : Labels

Which command should you run to connect a running container to an existing user-defined bridge


Options are :

  • docker network connect 'network name'
  • docker network attach 'network name' 'container name'
  • docker network connect 'network name' 'container name'
  • docker network 'network name' connect 'container name'

Answer : docker network connect 'network name' 'container name'

Docker Certified Associate (DCA) Practice Exams Set 9

Which command is used to delete a service from the swarm?


Options are :

  • docker service -d
  • docker service delete
  • docker service rm
  • docker service remove

Answer : docker service rm

Instead of enabling DCT through the system-wide configuration, DCT can be enabled or disabled on a per-shell or per-invocation basis


Options are :

  • TRUE
  • FALSE

Answer : TRUE

Swarm services connected to the same overlay network effectively expose all ports to each other.


Options are :

  • FALSE
  • TRUE

Answer : TRUE

Docker Certified Associate (DCA) Practice Exams Set 5

Which flag of 'docker service create' and 'docker service update' configures the maximum number of service tasks that the scheduler updates simultaneously?


Options are :

  • --parallel
  • --numjobs
  • --update-parallelism
  • -numtasks

Answer : --update-parallelism

When DCT is enabled in the Docker client, docker CLI commands that operate on tagged images must either have content signatures or explicit content hashes. Which docker command does not operate with DCT?


Options are :

  • pull
  • create
  • run
  • build
  • load
  • push

Answer : load

Which network driver connects multiple Docker daemons together and enables swarm services to communicate with each other, thereby removing the need to do OS-level routing between containers?


Options are :

  • overlay
  • none
  • host
  • bridge
  • macvlan

Answer : overlay

Docker Certified Associate (DCA) Practice Exams Set 26

With which type of mount may the data be stored anywhere on the host system?


Options are :

  • Regular
  • volumes
  • bind mounts
  • tempfs

Answer : bind mounts

Which command is used to get the state of a task?


Options are :

  • docker service task list
  • docker service ps
  • docker task list
  • docker task ls

Answer : docker service ps

Which of the following are valid states of the MANAGER STATUS column as shown when running 'docker node ls'? (select three)


Options are :

  • Available
  • Worker
  • Reachable
  • Leader
  • Unavailable

Answer : Reachable Leader Unavailable

Docker Certified Associate (DCA) Practice Exams Set 10

There are two ways to configure the Docker daemon:


Options are :

  • With flags when starting dockerd
  • an XML configuration file
  • a INI configuration file
  • a JSON configuration file

Answer : With flags when starting dockerd a JSON configuration file

By default the docker/dtr backup will perform an online backup


Options are :

  • FALSE
  • TRUE

Answer : TRUE

Which command is used to scale the number of containers / tasks in a service?


Options are :

  • docker service scale
  • docker service add-nodes
  • docker service scale-tasks
  • docker service add-tasks

Answer : docker service scale

Docker Certified Associate (DCA) Practice Exams Set 16

Which instruction copies new files, directories from <src> and adds them to the filesystem of the container at the path <dest>?


Options are :

  • FROM
  • COPY
  • ADD
  • INSERT

Answer : COPY

Which option of dockerd is useful for troubleshooting


Options are :

  • --debug
  • --verbose
  • --logdebug
  • --logging=10

Answer : --debug

Docker uses which technology to provide the isolated workspace that make up the container?


Options are :

  • HyperVisor
  • Hardware Abstraction
  • Namespaces
  • Virtual Names

Answer : Namespaces

Docker Certified Associate (DCA) Practice Exams Set 23

Command line arguments to docker run <image> will be appended after all elements in an exec form ENTRYPOINT, and will override all elements specified using CMD.


Options are :

  • TRUE
  • FALSE

Answer : TRUE

Which network driver allows you to assign a MAC address to a container, making it appear as a physical device on your network?


Options are :

  • macvlan
  • overlay
  • bridge
  • host
  • none

Answer : macvlan

Docker is written in which programming language?


Options are :

  • Go
  • .Net
  • Python
  • C

Answer : Go

Docker Certified Associate (DCA) Practice Exams Set 7

Which instruction will execute any commands in a new layer on top of the current image and commit the results?


Options are :

  • ARG
  • FROM
  • RUN
  • CMD

Answer : RUN

For a port to be accessible outside of the service, that port must be published. Which of the following options to 'docker service create' are valid methods of publishing port 80 on the service to port 8080 on the routing mesh? (select two)


Options are :

  • -p 80:8080
  • -p 8080:80
  • -p published=8080,target=80
  • -p published=80,target=8080

Answer : -p 8080:80 -p published=8080,target=80

Which command is used to see the list of running services?


Options are :

  • docker service ls
  • docker services list
  • docker swarm ls
  • docker service list

Answer : docker service ls

Docker Certified Associate (DCA) Practice Exams Set 9

What is used to define what goes on in the environment inside a container?


Options are :

  • Docker policy
  • Dockerfile
  • Docker initialization file
  • Docker template

Answer : Dockerfile

The docker logs command is not available for drivers other than json-file and journald.


Options are :

  • FALSE
  • TRUE

Answer : TRUE

Which of the following storage systems are supported by DTR?


Options are :

  • Microsoft Azure Blob storage
  • All of the storage systems are supported
  • Amazon S3 or compatible
  • Google Cloud Storage

Answer : All of the storage systems are supported

Docker Certified Associate (DCA) Practice Exams Set 7

When you receive the error below, what should you do?


docker login dtr.example.org

x509: certificate signed by unknown authority


Options are :

  • Phone Docker Support
  • Reinstall DTR
  • Install openssl
  • Get the DTR CA certificate and configure your operating system to trust that certificate

Answer : Get the DTR CA certificate and configure your operating system to trust that certificate

Docker manager nodes store the swarm state and manager logs in which location?


Options are :

  • /var/lib/docker/swarm/
  • /var/lib/docker/
  • /etc/docker/swarm/
  • /opt/docker/swarm/

Answer : /var/lib/docker/swarm/

Which type of mount is a good choice when you want to store your containerís data on a remote host or a cloud provider, rather than locally?


Options are :

  • volumes
  • tempfs
  • bind mounts
  • Regular

Answer : volumes

Docker Certified Associate (DCA) Practice Exams Set 16

Which of the following are valid states of the AVAILABILITY column as shown when running 'docker node ls'? (select three)


Options are :

  • Drain
  • Inactive
  • Pause
  • Active
  • Running

Answer : Drain Pause Active

In an environment where DOCKER_CONTENT_TRUST is set, which docker build flag allows individual operations on tagged images without DCT?


Options are :

  • --dct-off
  • --disable-dct
  • --disable-content-trust
  • --content-trust-off

Answer : --disable-content-trust

Which instruction allows you to configure a container that will run as an executable?


Options are :

  • ENTRYPOINT
  • ENV
  • RUN
  • CMD

Answer : ENTRYPOINT

Docker Certified Associate (DCA) Practice Exams Set 8

Docker Hub and Docker Cloud are examples of?


Options are :

  • docker templates
  • docker repos
  • docker libraries
  • docker registries

Answer : docker registries

Which of the following commands will publish a service's port, but only on nodes that are running a task for that service?


Options are :

  • docker service create -p 8080:80 nginx
  • docker service create -p mode=ingress,published=8082,target=80 nginx
  • docker service create -p mode=host,published=8082,target=80 nginx
  • docker service create -p 8080:80 --mode host nginx

Answer : docker service create -p mode=host,published=8082,target=80 nginx

Docker Certified Associate (DCA) Practice Exams Set 3

Which algorithm docker uses to maintain a consistent cluster state across multiple managers?


Options are :

  • Floyd's Cycle Detection Algorithm.
  • Round robin Algorithm
  • Lee algorithm
  • Raft consensus algorithm

Answer : Raft consensus algorithm

What is the docker run option to publish a port so that an application is accessible externally?


Options are :

  • docker run --open-port
  • docker run --expose
  • docker run --piblish-port
  • docker run --publish

Answer : docker run --publish

Which of the following is true of filesystem storage models? (select all that apply)


Options are :

  • They store data in regular files on the host machine.
  • They are efficient with write-heavy workloads.
  • They are used by overlay2 and aufs .
  • They use an external, object-based store.

Answer : They store data in regular files on the host machine. They are used by overlay2 and aufs .

Docker Certified Associate (DCA) Practice Exams Set 21

What is the recommended approach to set storage driver?


Options are :

  • Use --storage-driver flag when running dockerd
  • There is no such a feature to set storage driver options
  • Set the "storage-driver" option in the daemon.json file
  • Set the "storage" command line

Answer : Set the "storage-driver" option in the daemon.json file

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