Building a Go Application with CompileDaemon, Docker, and Docker Compose

Introduction

This guide explains how to set up and build a Go application using CompileDaemon for local development and Docker/Docker Compose for containerized deployment.

Prerequisites

1. Go Installed: Ensure Go is installed on your system. Verify your installation by running:

   go version

2. CompileDaemon Installed: Install CompileDaemon using:

   go install github.com/githubnemo/CompileDaemon@latest

3. Docker Installed: Ensure Docker is installed on your system. Check your installation with:

   docker --version

4. Docker Compose Installed (for Docker Compose only): Check Docker Compose installation:

   docker-compose --version

5. Setting Environment Variables:

   • Create a .env file in your project directory and set the following variables:

     PORT=1323
     # PostgreSQL connection variables
     DB="host=# user=# password=# dbname=# port=# sslmode=#"
     JWT_SECRET=

   • Replace host=#, user=#, password=#, dbname=#, port=#, and sslmode=# with your PostgreSQL connection details.

   • Set JWT_SECRET using a Linux command:

     openssl rand -base64 32

Steps to Build and Run the Go Application

Local Development with CompileDaemon

1. Navigate to Your Project Directory: Open your terminal and change to your Go project directory.

   cd /path/to/your/project

2. Organize Your Project Structure: Ensure your main.go file is located in the cmd/app directory (or adjust paths accordingly).

3. Run CompileDaemon: Start CompileDaemon to automatically build and restart your server on file changes.

   CompileDaemon --build="go build -o main ./cmd/app/main.go" --command="./main"

   • --build="go build -o main ./cmd/app/main.go": Specifies the build command to compile main.go into an executable named main.
   • --command="./main": Defines the command to run the compiled executable.

4. Verify Output: Upon running CompileDaemon, you should see output indicating successful builds and server restarts on file changes.

Containerized Deployment with Docker and Docker Compose

Docker Setup

1. Ensure Dockerfile: Confirm you have a Dockerfile in your project directory

2. Build Docker Image: Build the Docker image using the existing Dockerfile:

   docker build -t goland-app:latest .

Running Docker Container

1. Run Docker Container: Start a Docker container based on the built image:

   docker run -d --name auth-go -p 1323:1323 goland-app:latest

   • -d: Runs the container in detached mode.
   • --name auth-go: Assigns the name auth-go to the container.
   • -p 1323:1323: Maps port 8080 from the container to your host machine.

Using Docker Compose

1. Ensure docker-compose.yml: Confirm you have a docker-compose.yml file in your project directory

2. Build and Start Docker Compose: Build and start your application using Docker Compose:

   docker-compose up --build

   This command builds the Docker image defined in your Dockerfile, starts the container, and exposes port 1323.

Conclusion

Integrating CompileDaemon for local development and Docker/Docker Compose for containerized deployment simplifies the build and deployment process of your Go applications. It enhances development efficiency and ensures consistency across different environments.