feat: Add env_var support in ServiceConfig for custom environment variable names

Author: RandithaK

cmd/gateway/main.go

@@ -37,6 +37,7 @@ type ServiceConfig struct {
 	TargetURL    string `yaml:"target_url"`
 	StripPrefix  string `yaml:"strip_prefix"`
 	AuthRequired bool   `yaml:"auth_required"`
+	EnvVar       string `yaml:"env_var"` // Optional: custom environment variable name
 }
 
 // --- Global Logger ---
@@ -59,28 +60,28 @@ func loadConfig(path string) (*Config, error) {
 		config.JWTSecret = secret
 	}
 
-	// It maps the 'name' from config.yaml to the environment variable name
-	// from docker-compose.yml.
-	serviceURLEnvMap := map[string]string{
-		"auth":         "AUTH_SERVICE_URL",
-		"users":        "AUTH_SERVICE_URL", // "users" also points to the auth service
-		"vehicles":     "VEHICLE_SERVICE_URL",
-		"appointments": "APPOINTMENTS_SERVICE_URL",
-		"services":     "PROJECT_SERVICE_URL", // As defined in docker-compose, this is the project service
-		"projects":     "PROJECT_SERVICE_URL", // "projects" also points to this service
-		"time-logs":    "TIME_LOGGING_SERVICE_URL",
-		"payments":     "PAYMENT_SERVICE_URL",
-		"invoices":     "PAYMENT_SERVICE_URL", // "invoices" also points to this service
-		"admin":        "ADMIN_SERVICE_URL",
-		"websocket":    "WS_SERVICE_URL",
-		"ai":           "AI_SERVICE_URL",
-	}
-
+	// Override service URLs from environment variables
+	// If env_var is specified in config, use it; otherwise generate from service name
 	for i := range config.Services {
-		if envVar, ok := serviceURLEnvMap[config.Services[i].Name]; ok {
-			if url := os.Getenv(envVar); url != "" {
-				config.Services[i].TargetURL = url
-			}
+		var envVarName string
+
+		// Use custom env_var if specified, otherwise auto-generate
+		if config.Services[i].EnvVar != "" {
+			envVarName = config.Services[i].EnvVar
+		} else {
+			// Auto-generate: convert "service-name" to "SERVICE_NAME_SERVICE_URL"
+			// e.g., "time-logs" -> "TIME_LOGS_SERVICE_URL"
+			normalizedName := strings.ToUpper(strings.ReplaceAll(config.Services[i].Name, "-", "_"))
+			envVarName = normalizedName + "_SERVICE_URL"
+		}
+
+		// Override target URL if environment variable is set
+		if envURL := os.Getenv(envVarName); envURL != "" {
+			config.Services[i].TargetURL = envURL
+			logger.Info("Service URL overridden from environment",
+				"service", config.Services[i].Name,
+				"env_var", envVarName,
+				"url", envURL)
 		}
 	}
 

config.yaml

@@ -12,66 +12,84 @@ services:
     target_url: "http://localhost:8081"
     strip_prefix: "/api/v1/auth"
     auth_required: false # Login/Register must be public
+    env_var: "AUTH_SERVICE_URL"
 
   - name: "users"
     path_prefix: "/api/v1/users/"
     target_url: "http://localhost:8081" # Also points to the auth service
     strip_prefix: "/api/v1/users"
     auth_required: true
+    env_var: "AUTH_SERVICE_URL" # Shares the same backend as auth
 
   # --- Vehicle Service (Port 8082) ---
   - name: "vehicles"
     path_prefix: "/api/v1/vehicles/"
     target_url: "http://localhost:8082"
     strip_prefix: "/api/v1/vehicles"
     auth_required: true
+    # env_var not specified - will auto-generate: VEHICLES_SERVICE_URL
 
   # --- Appointment & Scheduling Service (Port 8083) ---
   - name: "appointments"
     path_prefix: "/api/v1/appointments/"
     target_url: "http://localhost:8083"
     strip_prefix: "/api/v1/appointments"
     auth_required: true
+    # env_var not specified - will auto-generate: APPOINTMENTS_SERVICE_URL
 
   # --- Service & Project Management Service (Port 8084) ---
   - name: "services"
     path_prefix: "/api/v1/services/"
     target_url: "http://localhost:8084"
     strip_prefix: "/api/v1/services"
     auth_required: true
+    env_var: "PROJECT_SERVICE_URL" # Points to project service
 
   - name: "projects"
     path_prefix: "/api/v1/projects/"
     target_url: "http://localhost:8084" # Also points to the project service
     strip_prefix: "/api/v1/projects"
     auth_required: true
+    env_var: "PROJECT_SERVICE_URL" # Shares the same backend
 
   # --- Time Logging Service (Port 8085) ---
   - name: "time-logs"
     path_prefix: "/api/v1/time-logs/"
     target_url: "http://localhost:8085"
     strip_prefix: "/api/v1/time-logs"
     auth_required: true
+    # env_var not specified - will auto-generate: TIME_LOGS_SERVICE_URL
 
   # --- Payment & Billing Service (Port 8086) ---
   - name: "payments"
     path_prefix: "/api/v1/payments/"
     target_url: "http://localhost:8086"
     strip_prefix: "/api/v1/payments"
     auth_required: true
+    env_var: "PAYMENT_SERVICE_URL"
 
   - name: "invoices"
     path_prefix: "/api/v1/invoices/"
     target_url: "http://localhost:8086" # Also points to the payment service
     strip_prefix: "/api/v1/invoices"
     auth_required: true
+    env_var: "PAYMENT_SERVICE_URL" # Shares the same backend
 
   # --- Admin & Reporting Service (Port 8087) ---
   - name: "admin"
     path_prefix: "/api/v1/admin/"
     target_url: "http://localhost:8087"
     strip_prefix: "/api/v1/admin"
     auth_required: true
+    # env_var not specified - will auto-generate: ADMIN_SERVICE_URL
+
+  # --- Notification Service (Port 8088) ---
+  - name: "notifications"
+    path_prefix: "/api/v1/notifications/"
+    target_url: "http://localhost:8088"
+    strip_prefix: "/api/v1/notifications"
+    auth_required: true
+    # env_var not specified - will auto-generate: NOTIFICATIONS_SERVICE_URL
 
   # --- Bonus Features (For Later Implementation) ---
   - name: "websocket"