Docker Docker Certified Associate DCA Questions & Answers

• Question 41:

  When an application being managed by UCP fails, you would like a summary of all requests made to the UCP API in the hours leading up to the failure.

  What must be configured correctly beforehand for this to be possible?

  A. UCP audit logs must be set to the metadata' or request' level.

  B. UCP logging levels must be set to the info' or debug' level.

  C. All engines in the cluster must have their log driver set to the metadata' or request' level.

  D. Set the logging level in theconfig object for the ucp-kube-api-server container to warning or higher.

  Correct Answer: A

• Question 42:

  The Kubernetes yaml shown below describes a networkPolicy.

  

  Will the networkPolicy BLOCK this traffic?

  Solution: a request issued from a pod lacking the tier: api label, to a pod bearing the tier: backend label

  A. Yes

  B. No

  Correct Answer: A

• Question 43:

  A docker service 'web' is running with a scale factor of 1 (replicas = 1).

  Bob intends to use the command 'docker service update --replicas=3 web'.

  Alice intends to use the command 'docker service scale web=3'. How do the outcomes oft these two commands differ?

  A. Bob's command results in an error. Alice's command updates the number of replicas of the 'web' service to 3.

  B. Bob's command only updates the service definition, but no new replicas are started. Alice's command results in the actual scaling up of the 'web' service.

  C. Bob's command updates the number of replicas of the 'web' service to 3. Alice's command results in an error.

  D. Both Bob's and Alice's commands result in exactly the same outcome, which is 3 instances of the 'web' service.

  Correct Answer: D

• Question 44:

  One of several containers in a pod is marked as unhealthy after failing its livenessProbe many times. Is this the action taken by the orchestrator to fix the unhealthy container?

  Solution: The unhealthy container is restarted.

  A. Yes

  B. No

  Correct Answer: B

• Question 45:

  In Docker Trusted Registry, how would a user prevent an image, for example 'nginx:latest' from being overwritten by another user with push access to the repository?

  A. Tag the image with 'nginx:immutable'

  B. Remove push access from all other users.

  C. Use the DTR web UI to make the tag immutable.

  D. Keep a backup copy of the image on another repository.

  Correct Answer: C

• Question 46:

  Two pods bear the same label, app: dev.

  Will a label selector matching app: dev match both of these pods?

  A. Yes, as long as all the containers in those pods are passing their livenessProbes and readinessProbes.

  B. Yes, if both pods were pre-existing when the label selector was declared.

  C. Yes, if the pods are in the same Kubernetes namespace as the object bearing the label selector

  D. Yes, if the pods are in the same Kubernetes namespace as the object bearing the label selector and both pods were preexisting when the label selector was declared.

  Correct Answer: D

• Question 47:

  You are pulling images from a Docker Trusted Registry installation configured to use self-signed

  certificates, and this error appears:

  'x509: certificate signed by unknown authority'.

  You already downloaded the Docker Trusted Registry certificate authority certificate from https://

  dtr.example.com/ca.

  How do you trust it? (Select two.)

  A. Place the certificate in '/etc/docker/dtr/dtr.example.com.crt' and restart the Docker daemon on all cluster nodes.

  B. Place the certificate in your OS certificate path, trust the certificate system-wide, and restart the Docker daemon across all cluster nodes.

  C. Pass '-trust-certificate ca.crt' to the Docker client.

  D. Pass --insecure-registry to the Docker client.

  E. Place the certificate in '/etc/docker/certs.d/dtr.example com/ca.crt' on all cluster nodes.

  Correct Answer: DE

• Question 48:

  You want to create a container that is reachable from its host's network. Does this action accomplish this? Solution: Use network attach to access the containers on the bridge network

  A. Yes

  B. No

  Correct Answer: B

• Question 49:

  Will this action upgrade Docker Engine CE to Docker Engine EE? Solution: Delete '/var/lib/docker' directory.

  A. Yes

  B. No

  Correct Answer: B

• Question 50:

  An application image runs in multiple environments, with each environment using different certificates and

  ports.

  Is this a way to provision configuration to containers at runtime?

  Solution: Provision a Docker config object for each environment.

  A. Yes

  B. No

  Correct Answer: A