Refactor Auth and HDFS controllers, fix User model, and improve HDFS config

- Rewrote AuthController to inject all dependencies via constructor
- Fixed token refresh/login logic and added rate limiter and blacklist support
- Implemented getters in LoginRequest DTO
- Updated User model to implement UserDetails and extend entity.User
- Switched HDFScontroller to use entity.User instead of models.User
- Rewrote HDFSConfig to include static getHDFS() method and secure config via env vars
- Simplified JwtService, added overload for entity.User, and fixed key handling

src/main/java/com/skycrate/backend/skycrateBackend/config/HDFSConfig.java

@@ -8,13 +8,35 @@ import org.springframework.context.annotation.Bean;
 import java.net.URI;
 import java.security.PrivilegedExceptionAction;
 
-
+ // HDFS configuration bean to securely connect to a remote Hadoop cluster.
+@Configuration
 public class HDFSConfig {
-    public static FileSystem getHDFS() throws Exception {
-        Configuration conf = new Configuration();
-        conf.set("fs.defaultFS", "hdfs://namenode:9000");
-        return FileSystem.get(new URI("hdfs://namenode:9000"), conf);
+
+    private static final String HDFS_URI = System.getenv("HDFS_URI"); // export HDFS_URI=hdfs://192.168.29.30:9000
+    private static final String HDFS_USER = System.getenv("HDFS_USER"); // Hadoop user (if needed)
+
+     // Configures and returns a secured HDFS FileSystem instance.
+    @Bean
+    public FileSystem fileSystem() throws Exception {
+        return getHDFS(); // use the static method internally
     }
 
+     // Static method to get a FileSystem instance. Used by other classes like HDFSController.
+    public static FileSystem getHDFS() throws Exception {
+        if (HDFS_URI == null || HDFS_URI.isBlank()) {
+            throw new IllegalStateException("HDFS_URI environment variable not set.");
+        }
 
-}
+        Configuration conf = new Configuration();
+        conf.set("fs.defaultFS", HDFS_URI);
+
+        if (HDFS_USER != null && !HDFS_USER.isBlank()) {
+            return UserGroupInformation.createRemoteUser(HDFS_USER)
+                    .doAs((PrivilegedExceptionAction<FileSystem>) () ->
+                            FileSystem.get(new URI(HDFS_URI), conf)
+                    );
+        } else {
+            return FileSystem.get(new URI(HDFS_URI), conf);
+        }
+    }
+}