Go API

A simple RESTful API for managing products built with Go, SQLite, sqlc, and goose.

Prerequisites

Before you begin, ensure you have the following installed on your system:

• Go 1.25.4 or higher
• sqlc - SQL code generator
• goose - Database migration tool

Installing sqlc

# macOS
brew install sqlc

# Linux
go install github.com/sqlc-dev/sqlc/cmd/sqlc@latest

# Or download binary from: https://github.com/sqlc-dev/sqlc/releases

Installing goose

# Using go install
go install github.com/pressly/goose/v3/cmd/goose@latest

# Or using brew (macOS)
brew install goose

Project Setup

1. Clone the Repository

git clone <repository-url>
cd go-api

2. Install Go Dependencies

go mod download

3. Configure Environment

Copy the example environment file:

cp .env.example .env

The .env file configures goose with the following settings:

• GOOSE_DRIVER=sqlite3 - Database driver
• GOOSE_DBSTRING=./products.db - Database file path
• GOOSE_MIGRATION_DIR=./internal/adapters/sqlite/migrations - Migration files directory

4. Run Database Migrations

The project uses goose for database migrations. With the .env file configured, you can run goose commands without passing arguments:

# Load environment variables (for current shell session)
source .env

# Run migrations (creates products.db database)
goose up

# Check migration status
goose status

Available goose commands:

• goose up - Run all pending migrations
• goose down - Roll back the last migration
• goose status - Show migration status
• goose reset - Roll back all migrations

Note: If you prefer not to use the .env file, you can still pass arguments directly:

goose -dir internal/adapters/sqlite/migrations sqlite3 products.db up

5. Generate Go Code from SQL

The project uses sqlc to generate type-safe Go code from SQL queries.

# Generate Go code from SQL queries
sqlc generate

This will generate the following files in internal/adapters/sqlite/sqlc/:

• db.go - Database interface
• models.go - Go structs for database tables
• queries.sql.go - Type-safe query functions

6. Run the Application

# Run the API server
go run ./cmd

# Or build and run
go build -o bin/api ./cmd
./bin/api

The server will start on http://localhost:8080

API Endpoints

Health Check

GET /health

Products

List all products

GET /products

Get product by ID

GET /products/{id}

Create product

POST /products
Content-Type: application/json

{
  "id": "product-123",
  "name": "Apple",
  "price_in_cents": 250,
  "quantity": 10,
  "created_at": 1738944000
}

Testing

You can test the API using the provided HTTP requests in http/products.http. These can be executed with:

• Kulala (Neovim plugin)
• REST Client (VS Code extension)
• cURL or any HTTP client

Example with cURL:

# Health check
curl http://localhost:8080/health

# List products
curl http://localhost:8080/products

# Create product
curl -X POST http://localhost:8080/products \
  -H "Content-Type: application/json" \
  -d '{
    "id": "product-123",
    "name": "Apple",
    "price_in_cents": 250,
    "quantity": 10,
    "created_at": 1738944000
  }'

Development Workflow

Adding New Database Tables

1. Make sure your .env is loaded:

source .env

2. Create a new migration file:

goose create add_new_table sql

3. Edit the generated migration file in internal/adapters/sqlite/migrations/

4. Run the migration:

goose up

Adding New Queries

1. Add your SQL query to internal/adapters/sqlite/sqlc/queries.sql

2. Regenerate Go code:

sqlc generate

3. Use the generated functions in your Go code

Rolling Back Migrations

# Make sure your .env is loaded
source .env

# Roll back the last migration
goose down

# Roll back all migrations
goose reset

Common Issues

sqlc: command not found

Make sure sqlc is installed and in your PATH:

export PATH=$PATH:$(go env GOPATH)/bin

goose: command not found

Make sure goose is installed and in your PATH:

export PATH=$PATH:$(go env GOPATH)/bin

Database locked error

If you get a "database is locked" error, make sure no other process is accessing products.db.

Tech Stack

• Go - Programming language
• Chi - HTTP router
• SQLite - Database
• sqlc - Type-safe SQL code generation
• goose - Database migrations
• slog - Structured logging