docker compose up and down - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the command docker compose up do?

It starts all the services defined in the docker-compose.yml file, creating containers if they don't exist.

beginner

What is the purpose of docker compose down?

It stops and removes all containers and networks created by docker compose up.

beginner

How can you run docker compose up in detached mode?

Add the -d flag: docker compose up -d. This runs containers in the background.

intermediate

What happens if you run docker compose up and the containers already exist?

Docker Compose will start the existing containers without recreating them unless the configuration has changed.

intermediate

Can docker compose down remove volumes? How?

Yes, by adding the -v flag: docker compose down -v removes volumes created by Compose.

What does docker compose up -d do?

A Builds images only

B Starts containers in the background

C Removes containers and networks

D Stops all running containers

The -d flag runs containers in detached mode, meaning in the background.

Which command stops and removes containers created by Docker Compose?

A docker compose run

B docker compose start

C docker compose build

D docker compose down

docker compose down stops and removes containers and networks.

How do you remove volumes when bringing down Docker Compose services?

A docker compose down -v

B docker compose rm -v

C docker compose down --remove-volumes

D docker volume rm

The -v flag with docker compose down removes volumes created by Compose.

If containers already exist, what does docker compose up do?

A Starts existing containers without recreating

B Deletes and recreates containers

C Does nothing

D Only builds images

Docker Compose starts existing containers unless configuration changes require recreation.

Which file does Docker Compose use to define services?

A compose.yaml

B Dockerfile

C docker-compose.yml

D dockerfile.yml

docker-compose.yml is the default file where services are defined for Docker Compose.

Explain what happens when you run docker compose up and how you can run it in the background.

Think about starting containers and running them without blocking your terminal.

Describe the purpose of docker compose down and how it affects containers, networks, and volumes.

Consider how to clean up everything Docker Compose created.

Practice

1. What does the command docker compose up do in a multi-container application?

easy

A. Deletes the docker-compose file

B. Stops and removes all containers

C. Starts all the containers defined in the docker-compose file

D. Builds images but does not start containers

Solution

1. Step 1: Understand the purpose of docker compose up

   This command reads the docker-compose.yml file and starts all the containers defined in it.

2. Step 2: Compare with other commands

   docker compose down stops and removes containers, so it is not the same as up.

3. Final Answer:

   Starts all the containers defined in the docker-compose file -> Option C

4. Quick Check:

   docker compose up = start containers [OK]

Hint: Remember: 'up' means start containers [OK]

Common Mistakes:

• Confusing 'up' with 'down'
• Thinking 'up' deletes files
• Assuming 'up' only builds images

2. Which of the following is the correct command to stop and remove all containers started by docker compose?

easy

A. docker compose stop

B. docker compose down

C. docker compose remove

D. docker compose kill

Solution

1. Step 1: Identify the command to stop and remove containers

   docker compose down stops and removes containers, networks, and default volumes created by up.

2. Step 2: Differentiate from other commands

   docker compose stop only stops containers but does not remove them. remove is not a valid command here.

3. Final Answer:

   docker compose down -> Option B

4. Quick Check:

   down = stop and remove [OK]

Hint: Use 'down' to stop and clean containers [OK]

Common Mistakes:

• Using 'stop' which doesn't remove containers
• Trying non-existent commands like 'remove'
• Confusing 'kill' with 'down'

3. Given this sequence of commands:
docker compose up -d
docker compose down
What will be the state of the containers after these commands?

medium

A. Containers are removed and not running

B. Containers are stopped but still exist

C. Containers are running in detached mode

D. Containers are paused

Solution

1. Step 1: Analyze docker compose up -d

   This starts containers in detached mode (running in background).

2. Step 2: Analyze docker compose down

   This stops and removes all containers started by up.

3. Final Answer:

   Containers are removed and not running -> Option A

4. Quick Check:

   up -d starts, down removes [OK]

Hint: 'down' removes containers even if started detached [OK]

Common Mistakes:

• Thinking containers remain stopped but not removed
• Confusing paused with stopped
• Assuming detached means containers stay after down

4. You ran docker compose down but your containers are still running. What is the most likely reason?

medium

A. You ran docker compose down in a different directory than the compose file

B. You forgot to add -d flag

C. The containers were started with docker run instead

D. Docker daemon is not running

Solution

1. Step 1: Understand how docker compose down works

   This command affects containers defined in the compose file in the current directory.

2. Step 2: Identify why containers remain running

   If run in a different directory, it won't find or stop those containers.

3. Final Answer:

   You ran docker compose down in a different directory than the compose file -> Option A

4. Quick Check:

   Correct directory needed for down [OK]

Hint: Run commands where your compose file is located [OK]

Common Mistakes:

• Thinking -d flag affects stopping containers
• Assuming down stops containers from docker run
• Not checking Docker daemon status

5. You want to restart your multi-container app with fresh containers, removing old volumes and networks. Which command should you run?

hard

A. docker compose up --build

B. docker compose stop && docker compose start

C. docker compose restart

D. docker compose down -v && docker compose up -d

Solution

1. Step 1: Understand the need to remove old volumes and networks

   Removing volumes requires the -v flag with docker compose down.

2. Step 2: Combine commands to remove and start fresh

   docker compose down -v removes containers, networks, and volumes; docker compose up -d starts fresh containers in detached mode.

3. Final Answer:

   docker compose down -v && docker compose up -d -> Option D

4. Quick Check:

   Use down -v to remove volumes before up [OK]

Hint: Use 'down -v' to remove volumes before 'up' [OK]

Common Mistakes:

• Using 'restart' which doesn't remove volumes
• Using 'stop' and 'start' which keep old volumes
• Assuming '--build' removes volumes