Dec 21, 20232 min read

Lab 9 -Setting up a Database with Docker Compose - Day 82

Welcome back to the #90DaysOfDevOps series! Today we will be discussing about Docker Compose. It is a powerful tool that allows you to define and manage multi-container Docker applications. In this tutorial, we'll use Docker Compose to set up a simple environment with a web application and a MySQL database. By the end of this guide, you'll have a basic understanding of how to use Docker Compose for container orchestration.

Prerequisites

Docker and Docker Compose:

Ensure that Docker and Docker Compose are installed on your system. You can download and install them from the official Docker website:

Docker: Install Docker
Docker Compose: Install Docker Compose

Step 1: Project Structure

Create a new directory for your project and navigate into it:

mkdir docker-compose-demo
cd docker-compose-demo

Step 2: Create Docker Compose File

Create a file named docker-compose.yml in your project directory. This file will define the services, networks, and volumes required for your application.

version: '3'
services:
  web:
    image: nginx:latest
    ports:
      - "8080:80"
  db:
    image: mysql:latest
    environment:
      MYSQL_ROOT_PASSWORD: root_password
      MYSQL_DATABASE: sample_db
      MYSQL_USER: db_user
      MYSQL_PASSWORD: db_password

In this example:

We define two services: web and db.
The web service uses the official Nginx image and maps port 8080 on the host to port 80 in the container.
The db service uses the official MySQL image and sets up environment variables for root password, database name, and user credentials.

Step 3: Start the Containers

Run the following command in your project directory to start the containers defined in the docker-compose.yml file:

docker-compose up -d

This command will download the necessary images (if not already downloaded) and start the containers in the background.

Step 4: Verify the Setup

Visit http://localhost:8080 in your web browser. You should see the default Nginx welcome page, indicating that the web container is running.

Step 5: Connect to the Database

Use a MySQL client or command-line tool to connect to the MySQL database. You can use the following credentials:

Host: localhost (or 127.0.0.1)
Port: 3306
Username: db_user
Password: db_password
Database: sample_db

Step 6: Stop and Cleanup

When you're done experimenting, stop the containers using the following command:

docker-compose down

This command stops and removes the containers, networks, and volumes defined in the docker-compose.yml file.

Congratulations! You've successfully set up a simple two-container environment with a web application and a MySQL database using Docker Compose. This example serves as a foundation for more complex multi-container applications and demonstrates the ease of container orchestration with Docker Compose.

Thank you for reading!

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