Docker & Containerization Flashcards
6 cards from real DevOps practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Docker & Containerization flashcards as text
What is a Docker image?
Answer: A read-only template used to create Docker containers
A Docker image is a read-only, layered template built from a Dockerfile that serves as the blueprint for creating containers.
Which Dockerfile instruction sets the base image for a build?
Answer: FROM
The FROM instruction in a Dockerfile specifies the parent image upon which all subsequent instructions are layered.
What command builds a Docker image from a Dockerfile in the current directory?
Answer: docker build .
The `docker build .` command reads the Dockerfile in the current directory and builds an image using that context.
What is the difference between a Docker container and a Docker image?
Answer: A container is a running instance of an image; an image is a static template
An image is a static, layered filesystem snapshot, while a container is a live, running process created from that image with a writable layer.
Which Docker networking driver allows containers on the same host to communicate using container names?
Answer: bridge
The bridge network driver creates a private internal network on the host and enables containers connected to the same bridge to communicate by name.
What does the EXPOSE instruction in a Dockerfile do?
Answer: Documents which port the container listens on at runtime
EXPOSE is documentation that informs Docker and users which port the container application listens on; it does not automatically publish the port to the host.