Quiz: Docker Fundamentals | Docker Fundamentals

1

What is the main benefit of using containers?

They make applications run faster They ensure consistent environments across development, testing, and production They reduce code complexity They eliminate the need for testing

2

What does 'docker build -t shopflow/api:1.0 .' do?

Runs a container named shopflow Builds an image from the Dockerfile in current directory and tags it Downloads the shopflow/api image Creates a new Dockerfile

3

Why is this Dockerfile inefficient for rebuilds?\n\nFROM node:20\nCOPY . .\nRUN npm install\nCMD [\

It uses the wrong base image npm install runs on every code change because COPY . . invalidates the cache CMD is in the wrong format It's missing WORKDIR

4

How do containers in a Docker Compose network communicate?

Through localhost Using service names as DNS hostnames Via shared volumes only They can't communicate directly

5

What happens to data in a container when it's removed (without volumes)?

It's automatically backed up It's permanently deleted It moves to the Docker daemon It stays in the image

6

What's wrong with this approach?\n\nDockerfile:\nENV STRIPE_KEY=sk_live_abc123

Environment variables aren't supported The secret is baked into the image and can be extracted It should use STRIPE_SECRET_KEY Nothing is wrong

7

What does '-p 8080:3000' do in docker run?

Sets process limit to 8080, timeout to 3000ms Maps host port 8080 to container port 3000 Exposes ports 8080 and 3000 Maps container port 8080 to host port 3000

8

Which command shows logs from the 'api' service in Docker Compose?

docker compose output api docker compose logs api docker compose show api docker compose cat api

9

Why use alpine-based images in production?

They have more pre-installed tools They're smaller with fewer potential vulnerabilities They're officially supported by Docker They run faster on all systems

10

What does 'depends_on' do in docker-compose.yml?

Shares environment variables between services Controls service startup order Links volumes together Installs dependencies

11

How would you persist a PostgreSQL database across container restarts?

Use the --persist flag Mount a volume to /var/lib/postgresql/data Enable auto-backup in the image Data persists automatically

12

What command rebuilds and restarts all services in Docker Compose?

docker compose restart --build docker compose up -d --build docker compose rebuild docker compose update

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