Docker Practice Exam 4
1) What is the default service mode on docker swarm, if not specified?
a) replicated
b) global
c) unified
d) standalone
2) What are the possible method(s) to deploy app containers on Docker EE?
a) deploy through UCP Web ui
b) deploy using docker client
c) deploy using kubectl
d) All of the above.
3) Which options can be added to reserve a given amount of memory and
number of CPUs for a service?
a) --limit-memory and --limit-cpu
b) --memory and --cpu
c) --reserve-memory and --reserver-cpu
d) -m and -c
4) Which option will enforce a service to only run on nodes with the label
“region” set to “east” and will fail if no appropriately labelled nodes are
available?
a) --constraint region==east
b) --region=east
c) --node-region=east
d) --label region=east
5) Which option will try to spread tasks evenly on every node which has a
“datacenter” node label attached to it, but will not fail if no appropriately
labeled nodes are available?
a) --constraint datacenter
b) --label datacenter
c) --placement-pref ‘spread=node.labels.datacenter’
d) --spread datacenter=
6) Which command will roll back to the previous version of the service
called “myapp”?
a) docker service update --rollback myapp
b) docker service rollback myapp
c) docker rollback service myapp
d) None of the above.
7) Which of the following command only removes stopped containers older
than 24 hours?
a) docker container prune
b) docker container rm --filter “until=24h”
c) docker rm --until 24h
d) docker container prune --filter “until=24h”
8) Which of the following commands will display information regarding the
amount of disk space used by the docker daemon?
a) df --filter docker
b) docker system df
c) docker disk usage
d) docker get diskusage
9) Which command can be used to get real-time events from the server?
a) docker system events
b) docker system logs
c) docker system realtime-events
d) docker system info
10) Which command can be used to ensure a worker node has successfully
joined a swarm, if run from the specified worker node?
a) docker node ls
b) docker swarm node
c) docker info
d) docker get node
11) Which command will display logs for a service called “helloapp”?
a) docker logs helloapp
b) docker service logs helloapp
c) docker get logs helloapp
d) docker logs --service helloapp
12) Which command when run on a manager, will list services running in
the swarm?
a) docker get service
b) docker list service
c) docker service ls
d) docker service list
13) Which port is used for communication between swarm nodes by
default?
a) 8080
b) 443
c) 21
d) 2377
14) If you have UCP clusters with 5 managers, how many managers can
you lose and still be able to schedule services?
a) 1
b) 2
c) 3
d) 4
15) Which command will allow us to inspect the build cache history of an
image?
a) docker image inspect <image id>
b) docker image cache <image id>
c) docker image history <image id>
d) docker image ls --cache
16) Which of the following instruction is not permitted to be used more
than once in a Dockerfile?
a) FROM
b) RUN
c) CMD
d) a and c
17) Which file, when present on context directory can increase the build’s
performance by excluding irrelevant files and directories specified on it?
a) .dockerignore
b) .gitexclude
c) .exlude
d) .skipthis
18) Which command will build an image and tag it into multiple
repositories?
a) docker build -t example/myapp:1.0.3:example/myapp:latest
b) docker build -t example/myapp:1.0.3 -t example/myapp:latest
c) docker build -t example/myapp:1.0.3 example/myapp:latest
d) docker build -t example/myapp:1.0.3:latest
19) Which Dockerfile instruction will add metadata to an image?
a) ARGS
b) ENV
c) LABEL
d) METADATA
20) Which Dockerfile instruction will inform Docker that the container
listens on the specified network ports at runtime?
a) EXPOSE
b) PORT
c) LISTEN
d) PUBLISH
21) Which Dockerfile instruction will tell Docker how to test a container to
check that it is still working?
a) TEST
b) LIVENESSPROBE
c) PROBE
d) HEALTHCHECK
22) What is the default logging driver for Docker service’s containers?
a) syslog
b) json-file
c) rsyslog
d) None of the above
23) Which command can be used to create a secret to be used by the swarm
Orchestrator?
a) docker secret create
b) docker new secret
c) docker add secret
d) docker secret add
24) Which of the following statements is incorrect?
a) A volume can be used by multiple containers
b) You can create a volume on the fly when you run new containers with -v
options
c) You can specify hostpath mount option on Dockerfile
d) You can specify the volume to be Read Only
25) Which command will create a service named “test-service” based on
“nginx:latest” image, that uses a volume named “myvol” mounted /app
inside the container?
a) docker service create --name test-service --mount
source=myvol,target=/app nginx:latest
b) docker service create --name test-service -v myvol:/app nginx:latest
c) docker service create --name test-service --volume myvol:/app
nginx:latest
d) b & c correct
26) Which network adapter will be used by default when you run “docker
network create mynetwork” without additional parameters?
a) overlay
b) overlay2
c) bridge
d) host
27) If containers “c1” are only attached to default network, container “c2”
only attached to “my_bridge” network and container “c3” attached to both
the default network and “my_bridge”. Which of the following statements is
true? ( Choose 3 answers )
a) c1 can reach c2 through it’s ipaddress
b) c2 can reach c3 through it’s hostname
c) c1 can reach c3 through it’s hostname
d) c3 can reach c1 through it’s ipaddress
28) Which command can be use to list the published ports of a container? (
Choose 3 answers)
a) docker port
b) docker ps
c) docker network
d) docker container inspect
29) Which command can be used to remove an existing network named
“my_bridge”?
a) docker rm my_bridge
b) docker rmi my_bridge
c) docker network rm my_bridge
d) docker rm --network my_bridge
30) Which command will connect the specified container to the specified
network after the container is running?
a) docker network connect <network name> <container name or id>
b) docker network attach <network name> <container name or id>
c) docker create network <network name> <container name or id>
d) docker network add <network name> <container name or id>
31) Which command will change the certificate rotation period from the
default of 90 days (168 hours) to one week, and rotate the certificate now?
a) docker swarm ca --rotate-cert 168h
b) docker swarm ca --rotate --cert-expiry 168h
c) docker ca --rotate --cert-expiry 168h
d) docker rotate ca --cert-expiry 168h
32) Which command will promote two worker node named “node-a” and
“node-b” into manager nodes?
a) docker node node-a node-b --promote
b) docker node node-a promote node-b
c) docker node modify node-a node-b role=manager
d) docker node promote node-a node-b
33) If you run “docker network create --driver overlay my_overlay”, when
does the driver actually created on the swarm nodes?
a) It will be created on all nodes only when the command is executed. So it
won’t be available on new nodes created after.
b) When the command is executed and additionally created when new
worker nodes are added.
c) When the service that is using “my_overlay” is scheduled on a node, the
driver will be created on the specified node.
d) None of the above
34) Which of the following are the 3 main Docker Container Network
Model components? (Choose 3 answers)
a) Sandbox
b) Endpoint
c) Network
d) Tunneling
35) Which command will create a container with custom DNS server(s)?
a) docker container create --dns=IP_ADDRESS
b) docker container create --dns=IP_ADDRESS
c) docker run --add-dns=IP_ADDRESS
d) docker container create --resolve=IP_ADDRESS
36) Which network driver is the best when you need containers running on
different Docker hosts to communicate?
a) macvlan
b) Host networks
c) Overlay networks
d) User-defined bridge networks
37) What is the Docker EE networking feature that allows you to specify
information in the HTTP header which UCP uses to route subsequent
requests to the same service task, for applications which require stateful
sessions?
a) Session Stickiness
b) HTTP Routing Mesh
c) Interlock
d) haproxy
38) What is the Docker EE networking feature that allows you to Publish a
service’s port and makes the service accessible at the published port on
every swarm node?
a) Session Stickiness
b) HTTP Routing Mesh
c) Interlock
d) haproxy
39) Which environment variable needs to be set on the OS to sign an image
before pushing it to the repository?
a) SIGN_DOCKER_IMAGE=1
b) DOCKER_IMAGE_SIGN=1
c) NOTARY_SIGNING=1
d) DOCKER_CONTENT_TRUST=1
40) Where is the Role Based Access Control configuration available?
a) docker client
b) docker swarm command
c) Universal Control Plane
d) b and c correct
41) Which of the following options when added to ‘docker container
inspect’ command will show JUST the IP address of a running container?
a) --show-ip
b) --format=”{{.NetworkSettings.Networks.bridge.IPAddress}”
c) --limit=IPAddress
c) None of the above.
42) Which tools can be used to deploy multiple containers using one
configuration file without creating a cluster?
a) kubernetes
b) dockerd
c) docker toolbox
d) docker-compose
43) A user reported that a service called “myweb” is not working properly.
Your cluster is still using the default logging drivers. Which command
should you use to gather information for troubleshooting?
a) docker service logs myweb
b) docker logs myweb
c) cat /var/log/messages | grep myweb
d) cat /var/log/docker
44) Which of the following commands will allow you to display the token
and command needed to join the existing cluster as a worker?
a) docker swarm list-tokens
b) docker swarm join-token worker
c) docker swarm token --worker
d) None of the above.
45) Which of the following commands will display all of the base images
available on local docker storage?
a) docker list
b) docker view images
c) docker images
d) docker list image
46) In what format is the output printed to terminal when you run ‘docker
inspect [container name]’ command (by default)?
a) JSON
b) YAML
c) CSV
d) HTML
47) Which of the following statements is not true?
a) You can attach multiple volumes on a container
b) You can attach multiple networks on a container
c) You can attach a volume to multiple containers
d) You can install multiple version of dockers in one host
48) Which command can be used to remove an image even if that image
has containers that are based on it?
a) docker image remove --all
b) docker rm [image name] --force
c) docker rmi [image name] --force
d) docker remove [image name]
49) Which option, when provided to a container at startup, will
automatically clean up the container and remove the file system when the
container exits?
a) --clean-up
b) --rm
c) --exit
d) --delete-on-exit
50) Which restart policies will make the Docker daemon try to restart the
container indefinitely and also always start on daemon startup, regardless of
the current state of the container?
a) on-failure
b) unless-stopped
c) always
d) no
Practice Exam 4 Answer Key
1) a
2) d
3) c
4) a
5) d
6) a
7) d
8) b
9) a
10) c
11) b
12) c
13) d
14) b
15) c
16) c
17) a
18) b
19) c
20) a
21) d
22) b
23) a
24) c
25) a
26) c
27) a, b, d
28) a, b, c
29) c
30) a
31) b
32) d
33) c
34) a, b, c
35) a
36) c
37) a
38) b
39) d
40) c
41) b
42) d
43) a
44) c
45) c
46) a
47) d
48) c
49) b
50) c