add: Environment Var support

internal/config/config.go

@@ -1,36 +1,39 @@
 package config
 
 import (
-	"GoMembership/internal/utils"
-	"GoMembership/pkg/logger"
 	"encoding/json"
 	"os"
 	"path/filepath"
-	"sync"
+
+	"github.com/kelseyhightower/envconfig"
+
+	"GoMembership/internal/utils"
+	"GoMembership/pkg/logger"
 )
 
 type DatabaseConfig struct {
-	Path string `json:"Path"`
+	Path string `json:"Path" envconfig:"DB_PATH"`
 }
 
 type AuthenticationConfig struct {
 	JWTSecret  string
 	CSRFSecret string
-	APIKEY     string `json:"APIKey"`
+	APIKEY     string `json:"APIKey" envconfig:"API_KEY"`
 }
 
 type SMTPConfig struct {
-	Host       string `json:"Host"`
-	User       string `json:"User"`
-	Password   string `json:"Password"`
-	Mailtype   string `json:"Mailtype"`
-	AdminEmail string `json:"AdminEmail"`
-	Port       int    `json:"Port"`
+	Host       string `json:"Host" envconfig:"SMTP_HOST"`
+	User       string `json:"User" envconfig:"SMTP_USER"`
+	Password   string `json:"Password" envconfig:"SMTP_PASS"`
+	Mailtype   string `json:"Mailtype" envconfig:"MAIL_TYPE"`
+	AdminEmail string `json:"AdminEmail" envconfig:"ADMIN_MAIL"`
+	Port       int    `json:"Port" envconfig:"SMTP_PORT"`
 }
 
 type TemplateConfig struct {
-	MailDir string `json:"MailDir"`
+	MailDir string `json:"MailDir" envconfig:"TEMPLATE_DIR"`
 }
+
 type Config struct {
 	Auth      AuthenticationConfig `json:"auth"`
 	DB        DatabaseConfig       `json:"db"`
@@ -39,46 +42,57 @@ type Config struct {
 }
 
 var (
-	pConfig Config
-	once    sync.Once
-	loaded  bool
+	CFG       Config
+	Auth      AuthenticationConfig
+	DB        DatabaseConfig
+	Templates TemplateConfig
+	SMTP      SMTPConfig
 )
 
-func LoadConfig() *Config {
+func LoadConfig() {
+	readFile(&CFG)
+	readEnv(&CFG)
+	csrfSecret, err := utils.GenerateRandomString(32)
+	if err != nil {
+		logger.Error.Fatalf("could not generate CSRF secret: %v", err)
+	}
+
+	jwtSecret, err := utils.GenerateRandomString(32)
+	if err != nil {
+		logger.Error.Fatalf("could not generate JWT secret: %v", err)
+	}
+	CFG.Auth.JWTSecret = jwtSecret
+	CFG.Auth.CSRFSecret = csrfSecret
+
+	Auth = CFG.Auth
+	DB = CFG.DB
+	Templates = CFG.Templates
+	SMTP = CFG.SMTP
+}
+
+func readFile(cfg *Config) {
 	path, err := os.Getwd()
 	if err != nil {
 		logger.Error.Fatalf("could not get working directory: %v", err)
 	}
 
 	configFile, err := os.Open(filepath.Join(path, "configs", "config.json"))
+	// configFile, err := os.Open("config.json")
 	if err != nil {
 		logger.Error.Fatalf("could not open config file: %v", err)
 	}
 	defer configFile.Close()
 
 	decoder := json.NewDecoder(configFile)
-	// pConfig = &Config{}
-	err = decoder.Decode(&pConfig)
+	err = decoder.Decode(cfg)
 	if err != nil {
 		logger.Error.Fatalf("could not decode config file: %v", err)
 	}
-	if !loaded {
-		once.Do(
-			func() {
-				csrfSecret, err := utils.GenerateRandomString(32)
-				if err != nil {
-					logger.Error.Fatalf("could not generate CSRF secret: %v", err)
-				}
-
-				jwtSecret, err := utils.GenerateRandomString(32)
-				if err != nil {
-					logger.Error.Fatalf("could not generate JWT secret: %v", err)
-				}
-				pConfig.Auth.JWTSecret = jwtSecret
-				pConfig.Auth.CSRFSecret = csrfSecret
-				loaded = true
-			})
-	}
-
-	return &pConfig
+}
+
+func readEnv(cfg *Config) {
+	err := envconfig.Process("", cfg)
+	if err != nil {
+		logger.Error.Fatalf("could not decode env variables: %#v", err)
+	}
 }