Docker: Containerization Fundamentals
Docker: Containerization Fundamentals
Test your knowledge up to 20 randomized questions
Welcome to the Docker Basics Quiz! This quiz is designed to test your understanding of fundamental Docker concepts, containerization, and best practices. Each question is multiple-choice, and you’ll find hints to help you along the way. Good luck!
Answer key and explanations30 questions
The quiz above draws 20 questions at random from these 30, so a second attempt will not be the same run. Everything in the pool is listed here.
Which Dockerfile instruction specifies the base image for a new container?
Answer`FROM`
Which command is used to build an image from a Dockerfile?
Answer`docker build`
What is the primary difference between CMD and ENTRYPOINT?
Answer`ENTRYPOINT` sets the executable; `CMD` sets default arguments
Which command displays the list of currently running containers?
Answer`docker ps`
What does the -d flag do when running a container?
AnswerStarts the container in detached background mode
Which instruction allows you to set environmental variables within a Dockerfile?
Answer`ENV`
What is a Docker "Layer"?
AnswerA read-only filesystem change from a command
How do you stop all running Docker containers at once?
Answer`docker stop $(docker ps -q)`
Which Docker network driver is the default for standalone containers?
Answer`Bridge`
What is the purpose of a Docker ".dockerignore" file?
AnswerExcludes local files from being sent to the build context
Which command allows you to enter a running container and start a shell?
Answer`docker exec -it <id> /bin/bash`
What is the command to delete a specific Docker image?
Answer`docker rmi`
What is a "Volume" in Docker?
AnswerA persistent storage area managed by Docker
In "docker run -p 8080:80 nginx", which port is the host port?
Answer8080
Which instruction defines the directory where subsequent commands will be executed?
Answer`WORKDIR`
What is "Multi-stage building"?
AnswerUsing separate stages to reduce final image size
Which command is used to see the metadata (IP, Config, etc.) of a container?
Answer`docker inspect`
What is the purpose of "Docker Hub"?
AnswerA public registry for sharing container images
What is "Copy-on-Write" (CoW)?
AnswerA strategy that copies files only when modified
Which command pulls an image from a registry without running it?
Answer`docker pull`
What does "docker system prune" do?
AnswerRemoves unused data like stopped containers
Which Dockerfile instruction is used to document intended ports?
Answer`EXPOSE`
What is a "Dangling Image"?
AnswerAn image that has no name tag or reference
Which command starts a previously stopped container?
Answer`docker start`
What is the default user in most Docker images if not specified?
Answer`root`
Which command logs you into a Docker registry?
Answer`docker login`
What is Docker Compose used for?
AnswerRunning multi-container apps using YAML files
Which flag is used to name a container during "docker run"?
Answer--name
What is the purpose of the "HEALTHCHECK" instruction?
AnswerTo check if the application inside is functional
What command shows the history of an image?
Answer`docker history`
