Skip to content

Latest commit

 

History

History
58 lines (40 loc) · 3.54 KB

introduction.md

File metadata and controls

58 lines (40 loc) · 3.54 KB

Introduction

What is Docker Compose

Docker Compose is an orchestration tool for defining and running multi-container Docker applications. It allows developers to streamline the process of managing application services by defining them in a single, human-readable file called a docker-compose.yml. It simplifies the orchestration of Docker containers by allowing developers to define the entire application stack, including services, networks, and volumes, in a single YAML file called docker-compose.yml. This file serves as the blueprint for your application, and Docker Compose uses it to manage the entire lifecycle of your application's containers.

When to use Docker Compose

Docker Compose is best suited for development, testing, and continuous integration environments where multiple containers need to be orchestrated as a single application. It is particularly helpful for managing microservices-based architectures, as it enables you to define the entire application stack in a single file. However, for more complex production environments and advanced container orchestration, it is recommended to use tools like Kubernetes or Docker Swarm, which provide additional features like automated scaling, docker secrets, rolling updates, and self-healing.

It has commands for managing the whole lifecycle of your multi-service application:

  • Start, stop, and rebuild services
  • View the status of running services
  • Stream the log output of running services
  • Run a one-off command on a service

Docker-Compose File

Using Compose is essentially a three-step process:

  • Define your app’s environment with a Dockerfile so it can be reproduced anywhere.
  • Define the services that make up your app in docker-compose.yml so they can be run together in an isolated environment.
  • Run docker compose up and the Docker compose command starts and runs your entire app. You can alternatively run docker-compose up using Compose standalone(docker-compose binary).

A docker-compose.yml looks like this:

version: "3.9"
services:
  web:
    build: .
    ports:
      - "8000:5000"
    volumes:
      - .:/code
      - logvolume01:/var/log
    depends_on:
      - redis
  redis:
    image: redis
volumes:
  logvolume01: {}

Advantages

Simplified management of multi-container applications: Docker Compose allows you to manage complex multi-container applications with ease, as it consolidates the configuration into a single, human-readable file.

Reproducible builds: By defining your application's container configurations in a docker-compose.yml file, you can ensure consistent development, testing, and production environments across your team.

Streamlined application deployment: With Docker Compose, deploying your application is as simple as running a single command, reducing the chances of manual errors and speeding up the deployment process.

Easier scaling and load balancing: Docker Compose enables you to scale your application services up or down depending on the workload, providing better resource utilization and improved performance.

Docker Compose vs Docker CLI

Docker Compose and Docker CLI are both tools for managing Docker containers. However, they serve different purposes. Docker CLI is a command-line interface for managing individual containers and images, whereas Docker Compose is specifically designed for orchestrating multi-container applications. Docker Compose allows you to define your application's services, networks, and volumes in a single file, making it easier to manage and deploy complex applications.