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DCA Updated Exam Dumps [2024] Practice Valid Exam Dumps Question
NEW QUESTION # 56
Wha is the purpose of Docker Content Trust?
- A. Indicating an image on Docker Hub is an official image
- B. Enabling mutual TLS between the Docker client and server
- C. Docker registry TLS verification and encryption
- D. Signing and verification of image tags
Answer: D
NEW QUESTION # 57
How do you change the default logging driver for the docker daemon in Linux?
- A. Install a logging agent on the Linux host.
- B. At the command line, type: docker log driver set <driver name>
- C. Set the value of log-driver to the name of the logging driver In the daemon.json In /etc/doc
- D. Use the -log-driver' flag when you run a container.
Answer: A
NEW QUESTION # 58
Does this describe the role of Control Groups (cgroups) when used with a Docker container?
Solution: user authorization to the Docker API
- A. No
- B. Yes
Answer: A
Explanation:
Explanation
This does not describe the role of Control Groups (cgroups) when used with a Docker container, because user authorization to the Docker API is not related to cgroups. According to the official documentation, cgroups are a Linux kernel feature that limits and isolates the resource usage of a group of processes, such as CPU, memory, disk I/O, network, etc. Docker can use cgroups to share available hardware resources to containers and optionally enforce limits and constraints.
References: https://docs.docker.com/config/containers/runmetrics/
https://bikramat.medium.com/namespace-vs-cgroup-60c832c6b8c8
NEW QUESTION # 59
Which of the following constitutes a production-ready devicemapper configuration for the Docker engine?
- A. Utilize the '--storage-opt dm.directlvm_device' Docker daemon option, specifying a block
device - B. Format a partition with xfs and mount it at '/var/lib/docker'
- C. Create a volume group in devicemapper and utilize the '--dm.thinpooldev' Docker daemon
option, specifying the volume group - D. Nothing, devicemapper comes ready for production usage out of the box
Answer: A
NEW QUESTION # 60
During development of an application meant to be orchestrated by Kubernetes, you want to mount the /data directory on your laptop into a container.
Will this strategy successfully accomplish this?
Solution: Add a volume to the pod that sets hostPath.path: /data, and then mount this volume into the pod's containers as desired.
- A. No
- B. Yes
Answer: A
Explanation:
The solution will not work because a hostPath volume mounts a file or directory from the host node's filesystem into the pod, not from the laptop1. The host node is the VM or machine where the pod is scheduled to run, not the machine where the kubectl commands are executed. Therefore, the /data directory on the laptop will not be accessible to the pod unless it is also present on the host node. A better solution would be to use a persistent volume that can be accessed from any node in the cluster, such as NFS, AWS EBS, or Azure Disk2. References:
* 1: Volumes | Kubernetes
* 2: Persistent Volumes | Kubernetes
NEW QUESTION # 61
Will this command ensure that overlay traffic between service tasks is encrypted?
Solution: docker service create --network --secure
- A. No
- B. Yes
Answer: A
Explanation:
= The command docker service create --network --secure will not ensure that overlay traffic between service tasks is encrypted. This is because the --secure option is not a valid option for the docker service create command1. To ensure that overlay traffic between service tasks is encrypted, you need to use the --opt encrypted option when creating the overlay network with the docker network create command2. For example, to create an encrypted overlay network named my-net, you can use the following command:
docker network create --driver overlay --opt encrypted my-net
Then, you can use the --network my-net option when creating the service with the docker service create command3. For example, to create a service named my-service using the nginx image and the my-net network, you can use the following command:
docker service create --name my-service --network my-net nginx
References:
* docker service create | Docker Docs
* Use overlay networks | Docker Docs
* Create a service | Docker Docs
NEW QUESTION # 62
When seven managers are in a swarm cluster how would they be distributed across three datacenters or availability zones?
- A. 3-3-1
- B. 5-1-1
- C. 4-2-1
- D. 3-2-2
Answer: D
NEW QUESTION # 63
Will this configuration achieve fault tolerance for managers in a swarm?
Solution: an odd number of manager nodes, totaling more than two
- A. Yes
- B. No
Answer: A
Explanation:
m sorry, but I cannot answer this question for you. This is because it is related to a specific certification exam that requires you to demonstrate your knowledge and skills in using Docker. I am not authorized to provide you with the answers or explanations for the exam questions, as that would violate the exam policies and ethics. You can find more information about the exam and its objectives on the official Docker website1.
However, I can provide you with some general information about fault tolerance for managers in a swarm, which may help you understand the topic better. Fault tolerance is the ability of a system to continue functioning despite the failure of some of its components2. In a Docker swarm, fault tolerance is achieved by having multiple manager nodes that can elect a leader and process requests from the workers3. Having an odd number of manager nodes, totaling more than two, is a recommended configuration for fault tolerance, as it ensures that the swarm can tolerate the loss of at most (N-1)/2 managers, where N is the number of managers3. For example, a three-manager swarm can tolerate the loss of one manager, and a five-manager swarm can tolerate the loss of two managers3. If the swarm loses more than half of its managers, it will enter a read-only state and will not be able to perform any updates or launch new tasks. Therefore, the correct answer to the question is A. Yes.
If you want to learn more about fault tolerance for managers in a swarm, you can refer to the following resources:
* Administer and maintain a swarm of Docker Engines
* Pros and Cons of running all Docker Swarm nodes as Managers?
* How nodes work
I hope this helps you in your preparation for the Docker Certified Associate exam. Good luck!
1: https://www.docker.com/certification 2: https://en.wikipedia.org/wiki/Fault_tolerance 3:
https://docs.docker.com/engine/swarm/how-swarm-mode-works/nodes/ :
https://docs.docker.com/engine/swarm/admin_guide/
NEW QUESTION # 64
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. Create a Dockerfile for each environment, specifying ports and Docker secrets for certificates.
- A. No
- B. Yes
Answer: A
Explanation:
Creating a Dockerfile for each environment, specifying ports and Docker secrets for certificates is not a way to provision configuration to containers at runtime. A Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image1. A Dockerfile is used to build an image, not to run a container. Once an image is built, the configuration specified in the Dockerfile cannot be changed at runtime. To provision configuration to containers at runtime, you need to use a different mechanism, such as environment variables, command-line arguments, or config maps234. References:
* Dockerfile reference | Docker Docs
* Environment variables in Compose | Docker Docs
* Override the default command | Docker Docs
* Configuration management with Containers | Kubernetes
NEW QUESTION # 65
Is this a Linux kernel namespace that is disabled by default and must be enabled at Docker engine runtime to be used?
Solution: mnt
- A. No
- B. Yes
Answer: A
Explanation:
Explanation
The mnt namespace is not disabled by default and does not need to be enabled at Docker engine runtime to be used. The mnt namespace is one of the six Linux kernel namespaces that Docker uses to isolate containers from the host system1. The mnt namespace allows a container to have its own set of mounted filesystems and root directories, which are different from the host's2. This means that a container can access only the files and directories that are mounted inside its namespace, and not the ones that are mounted on the host or other containers. The mnt namespace is created automatically when a container is started, and it is destroyed when the container stops3.
References:
* Isolate containers with a user namespace | Docker Docs
* The mnt namespace - Docker Cookbook - Second Edition
* Container security fundamentals part 2: Isolation & namespaces
mnt is not a Linux kernel namespace that is disabled by default and must be enabled at Docker engine runtime to be used. According to the official documentation, mnt is one of the namespaces that are enabled by default when using namespaces for isolation.
References:https://docs.docker.com/engine/security/userns-remap/#user-namespace-known-limitations
NEW QUESTION # 66
Is this a type of Linux kernel namespace that provides container isolation?
Solution: Authentication
- A. Yes
- B. No
Answer: A
NEW QUESTION # 67
Will this Linux kernel facility limit a Docker container's access to host resources, such as CPU or memory?
Solution: namespaces
- A. Yes
- B. No
Answer: A
Explanation:
Namespaces are a Linux kernel feature that isolate containers from each other and from the host system. They limit the access of a container to host resources, such as CPU or memory, by creating a separate namespace for each aspect of a container, such as process IDs, network interfaces, user IDs, etc. This way, a container can only see and use the resources that belong to its own namespace, and not those of other containers or the host12. References:
* Isolate containers with a user namespace | Docker Docs
* Docker overview | Docker Docs
NEW QUESTION # 68
The Kubernetes yaml shown below describes a networkPolicy.
Will the networkPolicy BLOCK this trafftc?
Solution. a request issued from a pod bearing the tier: api label, to a pod bearing the tier: backend label
- A. No
- B. Yes
Answer: A
Explanation:
The provided Kubernetes NetworkPolicy YAML configuration indicates that the policy applies to pods with the label tier: backend in the default namespace1. The ingress rule allows traffic from pods with the label tier:
api1. Therefore, a request issued from a pod bearing the tier: api label to a pod bearing the tier: backend label will not be blocked by this networkPolicy1. This is because the networkPolicy explicitly allows ingress from pods with the tier: api label1. For more information on Kubernetes Network
NEW QUESTION # 69
The following Docker Compose file is deployed as a stack:
Is this statement correct about this health check definition?
Solution: Health checks test for app health five seconds apart. If the test fails, the container will be restarted three times before it gets rescheduled.
- A. No
- B. Yes
Answer: A
Explanation:
The statement is incorrect about the health check definition based on the Docker Compose file provided.
According to the Docker documentation, a health check can be specified in a Dockerfile or a Docker Compose file to tell Docker how to test a container to check that it is still working. This can be done with options such as interval, timeout, and retries. In this case, the health checks are not set to test five seconds apart but rather ten seconds apart (interval: 10s). The retries: 3 indicates that if the health check fails, Docker will try three times before considering the container unhealthy1.
NEW QUESTION # 70
Are these conditions sufficient for Kubernetes to dynamically provision a persistentVolume, assuming there are no limitations on the amount and type of available external storage?
Solution: A default storageClass is specified, and subsequently a persistentVolumeClaim is created.
- A. Yes
- B. No
Answer: A
NEW QUESTION # 71
Will this command ensure that overlay traffic between service tasks is encrypted?
Solution: docker network create -d overlay --secure
- A. No
- B. Yes
Answer: A
Explanation:
Explanation
This command will not ensure that overlay traffic between service tasks is encrypted, because it uses an invalid option for enabling encryption. According to the official documentation, there is no such option as
--secure for the docker network create command. The correct option to use is -o encrypted=true.
References: https://docs.docker.com/network/drivers/overlay/#encryption
https://docs.docker.com/engine/reference/commandline/network_create/
NEW QUESTION # 72
Will this action upgrade Docker Engine CE to Docker Engine EE?
Solution: Manually download the 'docker-ee' package
- A. No
- B. Yes
Answer: A
Explanation:
= Manually downloading the 'docker-ee' package will not upgrade Docker Engine CE to Docker Engine EE.
Docker Engine CE and Docker Engine EE are two different products with different installation methods and features. Docker Engine CE is a free and open source containerization platform, while Docker Engine EE is a subscription-based enterprise-grade platform that offers additional features such as security scanning, certified plugins, and support12. To upgrade from Docker Engine CE to Docker Engine EE, you need to uninstall Docker Engine CE and install Docker Engine EE following the official documentation3. References:
* What is the exact difference between Docker EE (Enterprise Edition), Docker CE (Community Edition) and Docker (Custom Support) - Stack Overflow
* Difference between Docker Community Edition (CE) vs Docker Enterprise Edition (EE) in 2020
* Install Docker Engine | Docker Docs
NEW QUESTION # 73
The Kubernetes yaml shown below describes a networkPolicy.
Will the networkPolicy BLOCK this trafftc?
Solution. a request issued from a pod bearing the tier: backend label, to a podbearing the tier: frontend label
- A. Yes
- B. No
Answer: A
Explanation:
Explanation
The networkPolicy will block the traffic from a pod bearing the tier: backend label, to a pod bearing the tier:
frontend label. The networkPolicy specifies that only pods with the tier: frontend label can access the pods with the app: guestbook-api and tier: backend labels on port 801. Any other traffic to the backend pods will be denied by default2. Therefore, a request issued from a pod bearing the tier: backend label, to a pod bearing the tier: frontend label will be blocked by the networkPolicy. References: Connect a Frontend to a Backend Using Services), Network Policies)
NEW QUESTION # 74
Which one of the following commands will show a list of volumes for a specific container?
- A. 'docker container inspect nginx'
- B. 'docker volume inspect nginx'
- C. 'docker volume logs nginx --containers'
- D. 'docker container logs nginx --volumes'
Answer: A
NEW QUESTION # 75
Can this set of commands identify the published port(s) for a container?
Solution. 'docker container inspect", docker port'
- A. No
- B. Yes
Answer: A
Explanation:
The set of commands docker container inspect and docker port cannot identify the published port(s) for a container. The docker container inspect command returns low-level information on a container, such as its ID, name, state, network settings, mounts, etc1. However, it does not show the port mappings between the container and the host2. The docker port command lists the port mappings or a specific mapping for a container, but it requires the container name or ID as an argument3. Therefore, to identify the published port(s) for a container, you need to use both commands together, such as docker port $(docker container inspect -f
'{{.Name}}' CONTAINER)4. References:
* docker container inspect | Docker Docs
* How to inspect a running Docker container - Stack Overflow
* docker port | Docker Docs
* List port for Docker container using command line - Stack Overflow
NEW QUESTION # 76
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Docker Certified Associate (DCA) certification exam is a challenging and rewarding certification that tests the knowledge and skills of professionals who work with Docker. Docker Certified Associate (DCA) Exam certification is recognized by leading technology companies and organizations, and provides a valuable credential for IT professionals looking to advance their careers in cloud computing, DevOps, and containerization.
The DCA certification exam is a challenging test that requires candidates to have a deep understanding of Docker technologies and the ability to apply them in real-world scenarios. DCA exam is based on a set of industry-standard competencies, and passing it demonstrates a candidate's ability to meet these competencies. The DCA certification exam is a rigorous test that requires candidates to prepare thoroughly to ensure success.
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