DevOps Containerization Syllabus

Containerization syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Containerization in DevOps, not a summary of it.

1. 1

   Introduction to Containers

   2 topics

   • Container Concepts and Practices
   • Benefits of Containers
2. 2

   Docker Basics

   4 topics

   • Installing Docker
   • Docker Commands: build, run, images, ps
   • Dockerfile Basics
   • Docker Compose
3. 3

   Kubernetes Basics

   4 topics

   • Installing Kubernetes
   • Kubernetes Architecture
   • Kubernetes Objects: Pods, Services, Deployments
   • Helm

Containerization flashcards for DevOps

18 of 50 cards from the Containerization deck — real questions with worked answers.

1. What is a container in the context of software deployment?

   A lightweight, standalone, executable package that bundles an application together with its code, runtime, system libraries, and dependencies, so it runs consistently across any environment.

2. How does a container differ from a virtual machine (VM)?

   A container virtualizes the operating system and shares the host OS kernel (no guest OS), making it lightweight and fast to start; a VM virtualizes hardware and runs a full guest OS via a hypervisor, making it heavier and slower.

3. What two Linux kernel features make container isolation possible?

   Namespaces (isolate what a process can see: PIDs, network, mounts, users) and cgroups (control groups, which limit and account for resource usage such as CPU and memory).

4. What is a container image versus a running container?

   An image is a read-only template (a stack of layers) containing the app and its dependencies; a container is a running, writable instance created from that image.

5. List four key benefits of using containers.

   Portability (run anywhere), consistency across environments, efficient resource use / lightweight, fast startup, and easy scalability/isolation.

6. Why do containers start much faster than virtual machines?

   Containers share the host kernel and do not need to boot a separate guest operating system, so only the application process must start, taking seconds or less.

7. What problem does containerization solve regarding the phrase 'it works on my machine'?

   By packaging the app with all its dependencies into a portable image, the same environment runs identically on a developer laptop, CI server, and production, eliminating environment drift.

8. What is Docker?

   An open-source platform and runtime for building, shipping, and running applications inside containers using OS-level virtualization.

9. What is the Docker Engine composed of?

   The Docker daemon (dockerd, a long-running server process), a REST API, and the Docker CLI client that talks to the daemon.

10. What is Docker Hub?

    Docker's default public registry where container images can be stored, shared, and pulled (e.g., official images like nginx, ubuntu, postgres).

11. On Linux, what package commonly provides the easiest way to install Docker for development?

    Docker Desktop, or installing Docker Engine via the official convenience script / distribution package (e.g., apt-get install docker-ce on Debian/Ubuntu).

12. What command verifies that Docker is installed and the daemon is running?

    docker version (shows client and server versions) or docker info; docker run hello-world tests an end-to-end pull and run.

13. What does the command 'docker build' do?

    It reads a Dockerfile and build context and produces a container image, executing each instruction as a cached layer.

14. What is the purpose of the -t flag in 'docker build -t myapp:1.0 .'?

    It tags the resulting image with a name and tag (myapp version 1.0); the trailing dot specifies the current directory as the build context.

15. What does 'docker run' do?

    It creates a new container from an image and starts it, optionally pulling the image first if it is not present locally.

16. In 'docker run -d -p 8080:80 nginx', what do -d and -p mean?

    -d runs the container detached (in the background); -p 8080:80 publishes/maps host port 8080 to container port 80.

17. What does 'docker ps' show, and how do you see stopped containers too?

    docker ps lists running containers; docker ps -a lists all containers including stopped ones.

18. What does 'docker images' display?

    A list of images stored locally, showing repository, tag, image ID, creation date, and size.

See more Containerization flashcards →

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