How to Clear your Docker Certified Associate Exam

Hi! In this post, I will try to describe what is Docker Certified Associate Exam (DCA) is all about, why it is a good idea to learn Docker through it, and how can you prepare yourself for this exam. At the end of the post, you can find some useful resources that will help you during the preparations. So, let’s get started.

What is DCA

According to the official website:

“Docker Certified Associate (DCA) exam is designed to validate Docker skillset with real-world questions designed by experienced Docker practitioners. As the first exam in a comprehensive multi-tiered professional certification program, the DCA serves as a foundational benchmark for real-world Docker skills across the container industry”.

So basically if you a new to Docker and containers in general, this certification will help you to learn the topic pretty quick.

Now I want to tell you how such certifications as DCA helped me to booth my career as IT engineer (and why they can also help you to learn new things).

Let Me Tell You a Story

Back in the days, I was a Windows Server administrator in a small Russian town, I heard about Linux but I always didn’t have a time/motivation to learn it well. It turns out that the Linux certifications were something that can help me and they can become that motivators that I was looking for. So I decided to give them a shot and try to pass one of them.

The process looked like this: I’ve reserved the slot for one specific date, paid some money and started to prepare myself for the exam. I had a real deadline and I paid for the exam in advance, I had the motivation that I was needed and I didn’t wanna fail. I found the preparation guide and most of the answers online or through the paper books. I answered right for all the questions except one. I was really happy, my score was something like 95% but it wasn’t my goal. My goal was to learn basic concepts of Linux and I did it well.

After that, I’ve cleared more Linux exams and I actively started to use Linux in my work and as my main OS.

Later I started to search for the position of Linux engineer/sysadmin but my dream job was to join SUSE - the company that is developing my very favorite Linux OS. And I’ve got the job there! I think the number of certifications that I’ve received added some additional points to my resume and, honestly, I felt more confident during the interview.

That’s my short story - I hope I’ve convinced you that the right certificate can really booth your IT career. Now, let’s talk more about DCA.

Exam Details

Time

DCA is a typical IT exam - you have 55 multiple choice questions and you have to answer them within 90 minutes. You can answer them quickly if you really know the material but from my experience 90 minutes - is the right amount of time to answer all the questions and then to double check them.

Skill

You have to use Docker for at least 6 months, more is always better. Or you can start to use Docker while preparing for the exam (as I did with Linux), but you have to really use it.

Price

USD $195 or Euro €175 purchased online, but here is the trick - you can register for the exam on the events such as DockerCon and DcokerCon EU with some discount so better check out the official websites!

Results

Results delivered immediately. Don’t think that it’s how it’s supposed to be by default :) Take a look at AWS exams, you have to wait for 7!!! business days to receive the treasured letter.

Preparation

So you really wanna pass the DCA? Then you have to prepare yourself for it first! You can find the PDF with the Study Guide (without answers) here and then just go through all the questions and try to find the answers online. Or you can use the preparation guide I’ve created on GitHub will all answers. Just go through all of them and make sure you understood all concepts.

Sample Test Questions:

Here is the list of sample questions

Q1 Which command is used to place an image into a registry?

  1. docker commit
  2. docker tag
  3. docker push
  4. docker images
  5. docker pull

Q2. Which network allows Docker Trusted Registry components running on different nodes to communicate and replicate Docker Trusted Registry data?

  1. dtr-ol
  2. dtr-hosts
  3. dtr-br
  4. dtr-vlan

Q3. Which of the following is not an endpoint exposed by Docker Trusted Registry that can be used to assess the health of a Docker Trusted Registry replica?

  1. /health
  2. /nginx_status
  3. /api/v0/meta/cluster_status
  4. /replica_status

Q4. Which of the following endpoints exposed by Docker Trusted Registry can be used to assess the health of a Docker Trusted Registry replica?

  1. /health
  2. /api/health
  3. /replica_status
  4. /nginx/health

Q5. One of your developers is trying to push an image to the registry (dtr.example.com). The push fails with the error “denied: requested access to the resource is denied”. What should you verify the user has completed?

  1. docker login -u -p dtr.example.com
  2. docker registry login -u username -p dtr.example.com
  3. docker push /image:tag dtr.example.com
  4. docker images login -u -p dtr.example.com

Q6. You have been asked to backup the swarm state on a Linux installation. By default, where do Docker manager nodes store the swarm state and manager logs?

  1. /var/run/docker/swarm
  2. /var/lib/docker/swarm
  3. /etc/docker/swarm
  4. /run/docker/swarm

Q7. Which of the following will put the Docker engine into debug mode?

  1. echo ‘{“debug”: true}’ > /var/lib/docker/daemon.json ; sudo kill -HUP
  2. echo ‘{“debug”: true}’ > /etc/docker/config.json ; sudo kill -HUP
  3. echo ‘{“debug”: true}’ > /var/lib/docker/config.json ; sudo kill -HUP
  4. echo ‘{“debug”: true}’ > /etc/docker/daemon.json ; sudo kill -HUP

Q8. How do you deploy 4 new instances of nginx with a single command?

  1. docker service create –replicas 4 –name myservice nginx
  2. docker service create –instances 4 –name myservice nginx
  3. docker service scale myservice=4 nginx
  4. docker service scale –replicas 4 –name myservice nginx

Q9. You are using self-signed UCP certs and have a second DNS name that points to your internal controllers. When installing UCP, which flag should you use to add this additional name?

  1. –internal-server-cert
  2. –dns
  3. –san
  4. –external-server-cert

You can find all the answers to these questions in DCA Study Guide

I hope this post was helpful for you and feel free to reach me if you have any question about DCA Exam!

Good luck!