docker compose up and down - Commands & Configuration

Introduction

Running multiple containers together can be tricky. Docker Compose helps start and stop all related containers with simple commands, making it easy to manage multi-container apps.

When you want to start a web app and its database together on your local machine.

When you need to test how different services work together before deploying.

When you want to quickly stop all running containers of your app to free resources.

When you want to recreate containers after changing configuration or code.

When you want to share your app setup with teammates using a single file.

Config File - docker-compose.yml

docker-compose.yml

version: '3.9'
services:
  web:
    image: nginx:1.23
    ports:
      - "8080:80"
  db:
    image: postgres:15
    environment:
      POSTGRES_USER: user
      POSTGRES_PASSWORD: password
      POSTGRES_DB: exampledb

This file defines two services: web running an Nginx server and db running a PostgreSQL database.

The web service maps port 8080 on your computer to port 80 inside the container.

The db service sets environment variables to configure the database user, password, and database name.

Commands

Starts all services defined in the docker-compose.yml file in the background so you can keep using the terminal.

Terminal

docker compose up -d

Expected Output

Creating network "default" with the default driver

Creating volume "default" with default driver

Creating example_db_1 ... done

Creating example_web_1 ... done

→

-d - Run containers in detached mode (in the background)

Shows the status of all running containers started by Docker Compose to verify they are up.

Terminal

docker compose ps

Expected Output

NAME                COMMAND                  SERVICE             STATUS              PORTS

example_db_1        "docker-entrypoint.s…"   db                  running             5432/tcp

example_web_1       "nginx -g 'daemon off;'"   web                 running             0.0.0.0:8080->80/tcp

Stops and removes all containers, networks, and volumes created by docker compose up to clean up your environment.

Terminal

docker compose down

Expected Output

Stopping example_web_1   ... done

Stopping example_db_1    ... done

Removing example_web_1   ... done

Removing example_db_1    ... done

Removing network default

Key Concept

If you remember nothing else from this pattern, remember: docker compose up starts all your app's containers together, and docker compose down stops and cleans them up.

Common Mistakes

Running 'docker compose up' without the -d flag and expecting the terminal to be free.

Without -d, the command runs in the foreground and blocks the terminal until stopped.

Add the -d flag to run containers in the background: 'docker compose up -d'.

Running 'docker compose down' without realizing it removes containers and networks.

This deletes the running containers and network, so your app stops and data in volumes may be lost if not persisted.

Use 'docker compose down' only when you want to stop and clean up all resources; otherwise, use 'docker compose stop' to just stop containers.

Not checking container status after 'docker compose up' and assuming everything started correctly.

Containers might fail to start due to errors, but 'docker compose up' may not show this clearly without logs.

Run 'docker compose ps' to check status and 'docker compose logs' to see container output if needed.

Summary

Use 'docker compose up -d' to start all services in the background.

Check running containers with 'docker compose ps' to ensure they are healthy.

Use 'docker compose down' to stop and remove all containers and networks created.