Docker Containerization Docker Compose and Multi-Container Applications 2

Question 1

Which Docker Compose command stops and removes containers, networks, and volumes defined in the compose file?

Accepted Answer

docker compose down --volumes

Answer

docker compose down --volumes stops containers and removes containers, networks, and named volumes.

Question 2

In a Docker Compose file, what does the 'depends_on' directive control?

Accepted Answer

Startup and shutdown order of services

Answer

depends_on controls the order in which services start and stop, but does not wait for the service to be 'ready'.

Question 3

What is the default network behavior when services are defined in the same Docker Compose file?

Accepted Answer

All services are placed on a shared default bridge network

Answer

Docker Compose automatically creates a default bridge network that all services in the file join, enabling name-based DNS resolution.

Question 4

Which field in docker-compose.yml specifies environment variables loaded from an external file?

Accepted Answer

env_file

Answer

The env_file field loads environment variables from one or more external files into the container.

Question 5

What happens when you run 'docker compose up --scale web=3'?

Accepted Answer

Starts 3 instances of the web service

Answer

--scale web=3 starts three replicas of the web service within the same Compose project.

Docker Practice Test