Compose profiles for selective services in Docker - Mini Project: Build & Apply

Compose profiles for selective services

📖 Scenario: You are managing a small web application with multiple services. You want to run only specific services depending on the environment, like development or production, using Docker Compose profiles.

🎯 Goal: Learn how to create a docker-compose.yml file with profiles to selectively start services. You will define services and assign them to profiles, then run only the services for a chosen profile.

📋 What You'll Learn

Create a docker-compose.yml file with three services: web, db, and cache

Assign the web and db services to the prod profile

Assign the web and cache services to the dev profile

Use the profiles key in the compose file to specify profiles

Run docker compose --profile dev up to start only the dev profile services

💡 Why This Matters

🌍 Real World

In real projects, you often want to run only some services depending on the environment, like running a cache only in development but not in production.

💼 Career

Knowing how to use Docker Compose profiles helps you manage complex applications efficiently and is a valuable skill for DevOps and software engineers.

1

Create the base Docker Compose file with three services

Create a docker-compose.yml file with three services: web, db, and cache. Use the image nginx:alpine for web, postgres:alpine for db, and redis:alpine for cache. Do not add profiles yet.

Docker

# Create services web, db, and cache with specified images
# Your code here

Need a hint?

Use the services key and list each service with its image.

2

Add profiles to the services

Add the profiles key to assign services to profiles. Assign web and db to the prod profile. Assign web and cache to the dev profile.

Docker

version: '3.9'
services:
  web:
    image: nginx:alpine
    # Add profiles key here
  db:
    image: postgres:alpine
    # Add profiles key here
  cache:
    image: redis:alpine
    # Add profiles key here
# Your code here

Need a hint?

Use the profiles key under each service with a list of profile names.

3

Run Docker Compose with the dev profile

Write the exact command to start only the services in the dev profile using Docker Compose.

Docker

# Write the command to run docker compose with the dev profile
# Your code here

Need a hint?

Use docker compose --profile dev up to start only the dev profile services.

4

Display which services start with the dev profile

Write a command to list the running containers after starting the dev profile to confirm only web and cache are running.

Docker

# Write the command to list running containers
# Your code here

Need a hint?

Use docker ps to check running containers by name.