feat: user service

gateway/internal/config/config.go

@@ -45,6 +45,11 @@ const (
 	// public-auth delegation.
 	authServiceBaseURLEnvVar = "GATEWAY_AUTH_SERVICE_BASE_URL"
 
+	// userServiceBaseURLEnvVar names the environment variable that configures
+	// the optional User Service internal HTTP base URL used by authenticated
+	// gateway self-service delegation.
+	userServiceBaseURLEnvVar = "GATEWAY_USER_SERVICE_BASE_URL"
+
 	// adminHTTPAddrEnvVar names the environment variable that configures the
 	// private admin HTTP listener address. When it is empty, the admin listener
 	// remains disabled.
@@ -479,6 +484,15 @@ type AuthServiceConfig struct {
 	BaseURL string
 }
 
+// UserServiceConfig describes the optional authenticated self-service upstream
+// used by the gateway runtime.
+type UserServiceConfig struct {
+	// BaseURL is the absolute base URL of the User Service internal HTTP API.
+	// When BaseURL is empty, the gateway keeps using its built-in unavailable
+	// downstream adapter for the reserved `user.*` routes.
+	BaseURL string
+}
+
 // AdminHTTPConfig describes the private operational HTTP listener used for
 // metrics exposure. The listener remains disabled when Addr is empty.
 type AdminHTTPConfig struct {
@@ -610,6 +624,10 @@ type Config struct {
 	// Session Service.
 	AuthService AuthServiceConfig
 
+	// UserService configures the optional authenticated self-service
+	// delegation to User Service.
+	UserService UserServiceConfig
+
 	// AdminHTTP configures the optional private admin listener used for metrics
 	// exposure.
 	AdminHTTP AdminHTTPConfig
@@ -791,6 +809,13 @@ func DefaultAuthServiceConfig() AuthServiceConfig {
 	return AuthServiceConfig{}
 }
 
+// DefaultUserServiceConfig returns the default authenticated self-service
+// upstream settings. The zero value keeps the built-in unavailable adapter
+// active for reserved `user.*` routes.
+func DefaultUserServiceConfig() UserServiceConfig {
+	return UserServiceConfig{}
+}
+
 // LoadFromEnv loads Config from the process environment, applies defaults for
 // omitted settings, and validates the resulting values.
 func LoadFromEnv() (Config, error) {
@@ -799,6 +824,7 @@ func LoadFromEnv() (Config, error) {
 		Logging:            DefaultLoggingConfig(),
 		PublicHTTP:         DefaultPublicHTTPConfig(),
 		AuthService:        DefaultAuthServiceConfig(),
+		UserService:        DefaultUserServiceConfig(),
 		AdminHTTP:          DefaultAdminHTTPConfig(),
 		AuthenticatedGRPC:  DefaultAuthenticatedGRPCConfig(),
 		SessionCacheRedis:  DefaultSessionCacheRedisConfig(),
@@ -856,6 +882,11 @@ func LoadFromEnv() (Config, error) {
 		cfg.AuthService.BaseURL = rawAuthServiceBaseURL
 	}
 
+	rawUserServiceBaseURL, ok := os.LookupEnv(userServiceBaseURLEnvVar)
+	if ok {
+		cfg.UserService.BaseURL = rawUserServiceBaseURL
+	}
+
 	rawAdminHTTPAddr, ok := os.LookupEnv(adminHTTPAddrEnvVar)
 	if ok {
 		cfg.AdminHTTP.Addr = rawAdminHTTPAddr
@@ -1124,6 +1155,17 @@ func LoadFromEnv() (Config, error) {
 		}
 		cfg.AuthService.BaseURL = strings.TrimRight(parsedAuthServiceBaseURL.String(), "/")
 	}
+	cfg.UserService.BaseURL = strings.TrimSpace(cfg.UserService.BaseURL)
+	if cfg.UserService.BaseURL != "" {
+		parsedUserServiceBaseURL, err := url.Parse(cfg.UserService.BaseURL)
+		if err != nil {
+			return Config{}, fmt.Errorf("load gateway config: parse %s: %w", userServiceBaseURLEnvVar, err)
+		}
+		if parsedUserServiceBaseURL.Scheme == "" || parsedUserServiceBaseURL.Host == "" {
+			return Config{}, fmt.Errorf("load gateway config: %s must be an absolute URL", userServiceBaseURLEnvVar)
+		}
+		cfg.UserService.BaseURL = strings.TrimRight(parsedUserServiceBaseURL.String(), "/")
+	}
 	if addr := strings.TrimSpace(cfg.AdminHTTP.Addr); addr != "" {
 		cfg.AdminHTTP.Addr = addr
 	}