feat: implement donut as a service

.env.example

@@ -0,0 +1,7 @@
+DATABASE_HOST="localhost"
+DATABASE_PORT="5432"
+DATABASE_USERNAME="postgres"
+DATABASE_PASSWORD="postgres"
+DATABASE_SCHEMA="donut"
+DATABASE_DEBUG=TRUE
+DATABASE_DIALECT="postgres"

.gitignore

@@ -0,0 +1,4 @@
+postgres-data/
+
+# Ignore .env files as they are usually used to configure the app
+*.env

.vscode/launch.json

@@ -0,0 +1,36 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    // Use this for production build
+    {
+      "name": "Launch - Production",
+      "type": "go",
+      "request": "launch",
+      "mode": "auto",
+      "program": "${workspaceFolder}",
+      "args": ["."],
+      "stackTraceDepth": 100,
+      "console": "integratedTerminal",
+      "showLog": true,
+      "internalConsoleOptions": "openOnFirstSessionStart",
+      "showGlobalVariables": true,
+      "envFile": "${workspaceFolder}/.production.env"
+    },
+
+    // Use this for development build
+    {
+      "name": "Launch - Development",
+      "type": "go",
+      "request": "launch",
+      "mode": "auto",
+      "program": "${workspaceFolder}",
+      "args": ["."],
+      "stackTraceDepth": 100,
+      "console": "integratedTerminal",
+      "showLog": true,
+      "internalConsoleOptions": "openOnFirstSessionStart",
+      "showGlobalVariables": true,
+      "envFile": "${workspaceFolder}/.development.env"
+    }
+  ]
+}

application.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+type ApplicationConfig struct {
+	Host                    string `env:"APPLICATION_HOST" envDefault:"localhost"`
+	Port                    int    `env:"APPLICATION_PORT" envDefault:"8080"`
+	TZ                      string `env:"APPLICATION_TZ" envDefault:"Asia/Jakarta"`
+	GracefulShutdownTimeout int    `env:"APPLICATION_GRACEFUL_SHUTDOWN_TIMEOUT" envDefault:"10"`
+}
+
+func (cfg ApplicationConfig) Address() string {
+	return fmt.Sprintf("%s:%d", cfg.Host, cfg.Port)
+}

config.go

@@ -0,0 +1,16 @@
+package main
+
+import (
+	"github.com/caarlos0/env/v6"
+)
+
+type Config struct {
+	ApplicationConfig ApplicationConfig
+	DatabaseConfig    DatabaseConfig
+}
+
+func Get() (*Config, error) {
+	cfg := Config{}
+	err := env.Parse(&cfg)
+	return &cfg, err
+}

database.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"fmt"
+
+	"gorm.io/driver/mysql"
+	"gorm.io/driver/postgres"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+)
+
+type DatabaseDialect string
+
+const (
+	DialectMySQL    DatabaseDialect = "mysql"
+	DialectPostgres DatabaseDialect = "postgres"
+)
+
+type DatabaseConfig struct {
+	Host     string `env:"DATABASE_HOST"`
+	Port     int    `env:"DATABASE_PORT" envDefault:"3306"`
+	Username string `env:"DATABASE_USERNAME" envDefault:"root"`
+	Password string `env:"DATABASE_PASSWORD"`
+	Schema   string `env:"DATABASE_SCHEMA"`
+	Debug    bool   `env:"DATABASE_DEBUG" envDefault:"false"`
+	LogLevel string `env:"DATABASE_LOG_LEVEL" envDefault:"info" enum:"silent,error,warn,info"`
+	Dialect  string `env:"DATABASE_DIALECT"`
+}
+
+func (d DatabaseConfig) GetDialector() (gorm.Dialector, error) {
+	switch d.Dialect {
+	case string(DialectMySQL):
+		dsn := fmt.Sprintf(
+			"%s:%s@tcp(%s:%d)/%s?charset=utf8&parseTime=True&loc=Local",
+			d.Username,
+			d.Password,
+			d.Host,
+			d.Port,
+			d.Schema,
+		)
+		return mysql.Open(dsn), nil
+	case string(DialectPostgres):
+		dsn := fmt.Sprintf("host=%s user=%s password=%s dbname=%s port=%d sslmode=disable TimeZone=Asia/Jakarta",
+			d.Host,
+			d.Username,
+			d.Password,
+			d.Schema,
+			d.Port,
+		)
+		return postgres.Open(dsn), nil
+	default:
+		return nil, fmt.Errorf("unsupported database dialect: %s", d.Dialect)
+	}
+}
+
+func (d DatabaseConfig) GetLogLevel() logger.LogLevel {
+	switch d.LogLevel {
+	case "error":
+		return logger.Error
+	case "warn":
+		return logger.Warn
+	case "info":
+		return logger.Info
+	default:
+		return logger.Silent
+	}
+}

docker-compose.yml

@@ -0,0 +1,13 @@
+version: '3.3'
+
+services:
+  db:
+    image: postgres:9.6
+    container_name: donut
+    restart: always
+    environment:
+      POSTGRES_PASSWORD: postgres
+      POSTGRES_USER: postgres
+      POSTGRES_DB: postgres
+    ports:
+      - 5432:5432