How hard is the Docker Certified Associate exam?

DCA is considered a challenging exam that requires genuine hands-on Docker experience. You cannot pass by theory alone — the exam tests real CLI commands, Docker Compose syntax, Swarm orchestration, and troubleshooting scenarios. Most candidates need 6-12 months of Docker experience and 4-8 weeks of dedicated study.

What score do you need to pass the DCA exam?

The DCA exam has 55 questions in 90 minutes with a passing score of approximately 65-70%. Question types include multiple choice, multiple response, and discrete option multiple choice (DOMC) — where options are revealed one at a time. Scoring 80%+ on practice tests consistently is a reliable readiness indicator.

How long does it take to prepare for the Docker DCA exam?

With 1+ year of Docker experience, 4-8 weeks of focused study. Without prior Docker experience, build hands-on skills for 6-12 months first. The DCA is not an entry-level cert — Docker recommends 2+ years of practical experience. Focus heavily on Docker Swarm, networking, and security topics which are heavily weighted.

Docker DCA vs Kubernetes CKA — which should I get?

For production container orchestration jobs, CKA is more valuable — Kubernetes is the industry standard for orchestration. DCA focuses on Docker fundamentals and Swarm. Many candidates get DCA first to build container foundations, then CKA for Kubernetes orchestration. They complement each other well. See our DCA vs CKA comparison for a detailed breakdown.

Container Certifications March 26, 2026 19 min read

Free Docker Certification Practice Test 2026 — DCA Exam Questions with Real CLI Scenarios

Q: What is the Docker Certified Associate (DCA) exam?

The Docker Certified Associate (DCA) is a professional certification from Docker that validates expertise in Docker containerization and orchestration. It covers 6 domains: orchestration (25%), image creation/management (20%), installation/configuration (15%), networking (15%), security (15%), and storage/volumes (10%). It requires 2+ years of Docker experience and is aimed at DevOps engineers and container platform administrators.

Q: Is Docker DCA worth it in 2026?

Yes, especially for DevOps and platform engineering roles. While Kubernetes has largely overtaken Docker Swarm for production orchestration, Docker remains the dominant container runtime. DCA validates foundational container skills that every cloud-native engineer needs. It's often paired with CKA (Certified Kubernetes Administrator) for a comprehensive container platform skillset.

Reviewed by Docker Certified Associate professionals • About our team

The DCA exam tests real Docker skills — CLI commands, Swarm orchestration, networking, security. These practice questions reflect what appears on the actual certification exam.

What Makes the Docker DCA Different from Other Certs

Most cloud certifications test conceptual knowledge with multiple-choice questions. The Docker Certified Associate goes deeper — it expects you to know exact CLI commands, understand how Docker engine components interact, and troubleshoot real container scenarios. You can't wing this exam with passive reading.

The DCA uses DOMC (Discrete Option Multiple Choice) questions for a portion of the exam. Unlike standard multiple choice, DOMC reveals options one at a time and you answer true/false for each before seeing the next. This format requires genuine knowledge — you can't narrow it down by process of elimination.

If you're building toward Docker DCA, you should be running Docker daily. Pull images, build Dockerfiles, deploy stacks with Docker Compose, create Swarm clusters, configure overlay networks. Hands-on time is the only real preparation.

Docker DCA Exam Domains 2026

Domain	Weight	Key Topics
Orchestration	25%	Docker Swarm, services, stacks, nodes, scaling
Image Creation, Management & Registry	20%	Dockerfiles, layers, multi-stage builds, Docker Hub, DTR
Installation and Configuration	15%	Docker Engine, daemon config, storage drivers
Networking	15%	Bridge, overlay, host, macvlan networks, service discovery
Security	15%	Namespaces, cgroups, seccomp, image signing, UCP security
Storage and Volumes	10%	Volumes, bind mounts, storage drivers, tmpfs

Free Docker DCA Practice Questions — Orchestration

Question 1 — Docker Swarm

A DevOps engineer wants to scale a Docker Swarm service named "webapp" to 5 replicas. Which command achieves this?

A. docker service update --replicas 5 webapp

B. docker scale webapp=5

C. docker service scale webapp=5

D. docker swarm scale --service webapp --replicas 5

Both docker service scale webapp=5 and docker service update --replicas 5 webapp scale a Swarm service, but docker service scale is the canonical command for scaling. The format is docker service scale [SERVICE]=REPLICAS. Option A also works in practice, but C is the dedicated scale command. Options B and D use incorrect syntax — there is no docker scale command and no docker swarm scale command. Know your Docker CLI commands cold for the DCA.

Question 2 — Dockerfile Best Practices

A developer wants to build a production Docker image for a Go application. The final image should be as small as possible and not include the Go compiler or build tools. Which Dockerfile approach BEST achieves this?

A. Use a golang base image and RUN commands to delete build tools after compilation

B. Use a multi-stage build — build in golang image, copy binary to scratch or distroless image

C. Build the binary on the host and COPY it into an alpine base image

D. Use .dockerignore to exclude Go compiler files from the final image

Multi-stage builds are the Docker-recommended approach for minimal production images. Stage 1: use the full golang image to compile the binary. Stage 2: use FROM scratch or a minimal base (alpine, distroless) and COPY --from=build to copy only the compiled binary. The build tools never end up in the final image. Option A doesn't work — deleting files in a later RUN layer doesn't remove them from the image layers (they still exist in the layer history). Option C works but ties the build to host OS/arch. Option D misunderstands .dockerignore (it excludes build context files, not image contents).

Free Docker DCA Practice Questions — Networking

Question 3 — Docker Networks

Two containers running on the SAME Docker host need to communicate using container names (not IP addresses). Which network driver enables this?

A. host

B. default bridge (docker0)

C. overlay

D. user-defined bridge network

User-defined bridge networks provide automatic DNS resolution between containers by container name. The default docker0 bridge does NOT provide DNS — containers can only communicate by IP. Host network shares the host's network namespace (no isolation). Overlay is for multi-host Swarm communication. Always use user-defined bridge networks for same-host container communication that needs name resolution — it's a Docker networking best practice tested heavily on DCA.

Question 4 — Docker Security

A security engineer wants to restrict a Docker container so it cannot make specific system calls to the kernel, reducing the container's attack surface. Which Linux security feature achieves this?

A. seccomp (secure computing mode)

B. Linux namespaces

C. cgroups (control groups)

D. AppArmor profiles

seccomp (Secure Computing Mode) is a Linux kernel feature that restricts which system calls a process can make. Docker applies a default seccomp profile that blocks ~44 system calls. Custom seccomp profiles further restrict the attack surface. Namespaces provide isolation (PID, network, mount, etc.) — not syscall filtering. cgroups limit resource usage (CPU, memory) — not syscall filtering. AppArmor is a MAC (Mandatory Access Control) system that restricts file/network access, not syscalls directly (though the distinction is subtle). For syscall filtering specifically, seccomp is correct.

Question 5 — Volumes vs Bind Mounts

A container needs to persist database data that should survive container restarts and be shareable between multiple containers. The data should be managed by Docker and not depend on a specific host directory path. Which storage method is MOST appropriate?

A. Bind mount to /var/lib/myapp on the host

B. Docker named volume

C. tmpfs mount

D. Anonymous volume

Docker named volumes are managed by Docker (stored in /var/lib/docker/volumes/), persist across container lifecycles, and can be shared between containers. They don't depend on specific host paths — Docker handles the location. Bind mounts depend on a specific host directory path (host-dependent). tmpfs is in-memory only — data is lost when the container stops. Anonymous volumes persist but can't be referenced by name for sharing. Named volumes are the Docker-recommended approach for persistent, shareable data.

Docker CLI Commands You Must Know for the DCA

Container Management

# Run a container in detached mode with port mapping docker run -d -p 8080:80 --name webserver nginx # Execute a command in a running container docker exec -it webserver bash # View container logs with timestamps docker logs --timestamps webserver # Inspect container details (IP, mounts, env) docker inspect webserver

Image Management

# Build an image from Dockerfile with tag docker build -t myapp:v1.0 . # Tag an image for a registry docker tag myapp:v1.0 registry.example.com/myapp:v1.0 # Push to registry docker push registry.example.com/myapp:v1.0 # View image layers docker history myapp:v1.0

Swarm Management

# Initialize Swarm on manager node docker swarm init --advertise-addr 192.168.1.10 # Create a service with 3 replicas docker service create --name webapp --replicas 3 -p 80:80 nginx # Scale a service docker service scale webapp=5 # List services and their replica status docker service ls docker service ps webapp

DCA exam tip: Orchestration (25%) and Image Management (20%) together are nearly half the exam. Focus your CLI practice on Swarm commands (service create/update/scale, node promotion/demotion), Dockerfile optimization (multi-stage builds, layer caching, .dockerignore), and network types (bridge vs overlay vs host). These three areas covered well will get you through the majority of DCA questions.

ExamCert's Docker DCA Coverage

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Docker DCA vs Kubernetes CKA — Which First?
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Frequently Asked Questions — Docker Certification Practice Test

What is the Docker Certified Associate (DCA) exam?

A professional Docker certification covering containers, Swarm orchestration, networking, security, image management, and storage. 55 questions, 90 minutes. Requires genuine hands-on Docker experience to pass.

How hard is the Docker DCA exam?

Challenging — you need real CLI experience. Theory alone won't pass it. DCA uses DOMC (Discrete Option Multiple Choice) for some questions, which requires genuine knowledge. Most candidates need 6-12 months of Docker hands-on experience before taking the exam.

Is Docker DCA worth it in 2026?

Yes, for DevOps and platform engineering roles. Docker remains the dominant container runtime. DCA validates foundational container skills — often paired with CKA (Certified Kubernetes Administrator) for a comprehensive container platform skillset.

Docker DCA vs CKA — which should I get first?

DCA first if you're newer to containers — it builds the fundamentals. CKA first if you're already deploying containers and need to focus on orchestration. Many engineers get both: DCA for Docker mastery, CKA for Kubernetes orchestration. See our DCA vs CKA comparison.

What Docker commands do I need to know for the DCA?

Focus on: docker service (create/scale/update/ps/ls), docker swarm (init/join/leave), docker network (create/ls/inspect), docker volume (create/ls/inspect), docker build/tag/push/pull, docker inspect, docker logs, and docker exec. Know syntax cold — the exam tests exact commands.