DevOps Docker & Containerization

Question 1

What is a Docker image?

Accepted Answer

A read-only template used to create Docker containers

Answer

A Docker image is a read-only, layered template built from a Dockerfile that serves as the blueprint for creating containers.

Question 2

Which Dockerfile instruction sets the base image for a build?

Accepted Answer

FROM

Answer

The FROM instruction in a Dockerfile specifies the parent image upon which all subsequent instructions are layered.

Question 3

What command builds a Docker image from a Dockerfile in the current directory?

Accepted Answer

docker build .

Answer

The `docker build .` command reads the Dockerfile in the current directory and builds an image using that context.

Question 4

What is the difference between a Docker container and a Docker image?

Accepted Answer

A container is a running instance of an image; an image is a static template

Answer

An image is a static, layered filesystem snapshot, while a container is a live, running process created from that image with a writable layer.

Question 5

Which Docker networking driver allows containers on the same host to communicate using container names?

Accepted Answer

bridge

Answer

The bridge network driver creates a private internal network on the host and enables containers connected to the same bridge to communicate by name.

DevOps Practice Test