What is Docker Compose?

Docker Compose is a tool for defining and running multi-container Docker applications. It allows managing multiple related services in a single configuration file.

Key features:

• Works on all platforms supporting Docker.
• Uses a YAML file format (docker-compose.yml) to describe services, networks, and volumes.
• Enables defining dependencies between services.
• Ensures reproducibility of environments for development, testing, and production.

Main commands:

Command	Description
up	Creates and starts services.
down	Stops and removes containers, networks, volumes, and images (by default).
build	Builds images for services.
start	Starts stopped services.
stop	Stops running services.
restart	Restarts services.
ps	Displays container status.
logs	Shows service logs.
exec	Executes a command in a running container.

Simple example of a docker-compose.yml file:

version: '3.8' # Compose syntax version

services:
  web: # Service name
    image: nginx:latest # Used image
    ports:
      - "80:80" # Port forwarding (host:container)
    volumes:
      - ./html:/usr/share/nginx/html # Volume mounting (host:container)
  app: # Another service
    build: . # Builds image from Dockerfile in current directory
    ports:
      - "5000:5000"
    depends_on: # Dependency: app starts after web
      - web