Using Go + Docker Compose + MySQL: An Example

In this article, we'll walk through an example of how to set up a Go application with a MySQL database using Docker Compose. This approach simplifies development by managing dependencies and configurations using containers.

Prerequisites

• Basic understanding of Go programming language.
• Docker and Docker Compose installed on your machine.

Step 1: Set Up the Go Application

First, let’s create a simple Go application that will connect to a MySQL database. Start by creating a directory for your project:

mkdir go-docker-example
cd go-docker-example

Create a Go module:

go mod init go-docker-example

Next, create a simple Go application file:

package main

import (
    "database/sql"
    "fmt"
    _ "github.com/go-sql-driver/mysql"
)

func main() {
    dsn := "user:password@tcp(mysql:3306)/dbname"
    db, err := sql.Open("mysql", dsn)
    if err != nil {
        panic(err)
    }
    defer db.Close()

    err = db.Ping()
    if err != nil {
        panic(err)
    }
    fmt.Println("Connected to MySQL database!")
}

This code Example is a very basic Go application that connects to a MySQL database using the Go SQL package and MySQL driver.

Step 2: Create the Docker Compose File

Create a docker-compose.yml file in your project directory:

version: '3.8'

services:
  app:
    build: .
    depends_on:
      - mysql

  mysql:
    image: mysql:latest
    ports:
      - "3306:3306"
    environment:
      MYSQL_ROOT_PASSWORD: password
      MYSQL_DATABASE: dbname
      MYSQL_USER: user
      MYSQL_PASSWORD: password

This YAML configuration defines two services: one for your Go application and another one for MySQL. Ensure to update the credentials as you set in your Go application.