feat(auth): add dedicated JWT token validation endpoint

- Implemented a new endpoint `/auth/validate` to validate JWT tokens for external services, returning essential user information.
- Introduced a handler method `ValidateToken` in the user handler to manage token validation logic, including Redis blacklist checks.
- Updated API documentation to include the new endpoint and its usage details.
- Enhanced existing user management documentation to reflect the addition of the token validation feature.

Author: gjovanovicst

README.md

@@ -159,6 +159,7 @@ The following `make` commands are available for development, testing, building,
 
 ### User Management
 - `GET /profile` — Get user profile (protected)
+- `GET /auth/validate` — Validate JWT token for external services (protected)
 
 ### Activity Logs
 - `GET /activity-logs` — Get authenticated user's activity logs with pagination and filtering (protected)

cmd/api/main.go

@@ -119,6 +119,7 @@ func main() {
 	protected.Use(middleware.AuthMiddleware())
 	{
 		protected.GET("/profile", userHandler.GetProfile)
+		protected.GET("/auth/validate", userHandler.ValidateToken)
 		protected.POST("/logout", userHandler.Logout)
 
 		// 2FA management routes

docker-compose.dev.yml

@@ -22,6 +22,13 @@ services:
       redis:
         condition: service_healthy
     restart: unless-stopped
+    networks:
+      - default
+      - shared-api-network
 
 volumes:
   go_modules:
+
+networks:
+  shared-api-network:
+    external: true

docker-compose.yml

@@ -18,6 +18,9 @@ services:
       interval: 10s
       timeout: 5s
       retries: 5
+    networks:
+      - default
+      - shared-api-network
 
   # Redis Cache
   redis:
@@ -32,6 +35,9 @@ services:
       interval: 10s
       timeout: 5s
       retries: 5
+    networks:
+      - default
+      - shared-api-network
 
   # Redis Commander - Web UI for Redis Management
   redis-commander:
@@ -47,6 +53,8 @@ services:
     depends_on:
       - redis
     restart: unless-stopped
+    networks:
+      - default
 
   # Go Auth API Application
   auth-api:
@@ -64,7 +72,14 @@ services:
       redis:
         condition: service_healthy
     restart: unless-stopped
+    networks:
+      - default
+      - shared-api-network
 
 volumes:
   postgres_data:
   redis_data:
+
+networks:
+  shared-api-network:
+    external: true

docs/API.md

@@ -46,5 +46,10 @@
 - Header: `Authorization: Bearer <token>`
 - Response: `{ "success": true, "data": { ...user... } }`
 
+### Token Validation (for external services)
+- `GET /auth/validate`
+- Header: `Authorization: Bearer <token>`
+- Response: `{ "valid": true, "userID": "uuid", "email": "[email protected]" }`
+
 ---
 For more details, see the OpenAPI spec (if available) or code comments.