feat: Add support for X-Forwarded-Prefix

Change-Id: I200d5e1567118a026ac951389e616358cf81bba9
Signed-off-by: Florent Benoit <[email protected]>

server/src/main/java/org/eclipse/openvsx/util/UrlUtil.java

@@ -86,7 +86,7 @@ public static String getBaseUrl() {
         return getBaseUrl(requestAttrs.getRequest());
     }
 
-    private static String getBaseUrl(HttpServletRequest request) {
+    protected static String getBaseUrl(HttpServletRequest request) {
         var url = new StringBuilder();
 
         // Use the scheme from the X-Forwarded-Proto header if present
@@ -132,6 +132,16 @@ private static String getBaseUrl(HttpServletRequest request) {
                 break;
         }
 
+        // Use the prefix from the X-Forwarded-Prefix header if present
+        String prefix;
+        var forwardedPrefix = request.getHeader("X-Forwarded-Prefix");
+        if (forwardedPrefix == null) {
+            prefix = "";
+        } else {
+            prefix = forwardedPrefix;
+        }
+        url.append(prefix);
+
         url.append(request.getContextPath());
         return url.toString();
     }

server/src/test/java/org/eclipse/openvsx/util/UriUtilTest.java

@@ -10,11 +10,33 @@
 package org.eclipse.openvsx.util;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.doReturn;
 
+import javax.servlet.http.HttpServletRequest;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
 
 public class UriUtilTest {
 
+    @Mock
+    private HttpServletRequest request;
+
+    private AutoCloseable closeable;
+
+    @BeforeEach
+    public void openMocks() {
+     closeable = MockitoAnnotations.openMocks(this);
+    }
+
+    @AfterEach
+    public void releaseMocks() throws Exception {
+        closeable.close();
+    }
+
     @Test
     public void testApiUrl() throws Exception {
         var baseUrl = "http://localhost/";
@@ -29,4 +51,30 @@ public void testQuery() throws Exception {
                 .isEqualTo("http://localhost/api/foo?a=1&c=b%09a%2Fr");
     }
 
-}
+    // Check base URL is localhost:8080 if there is no XForwarded headers
+    @Test
+    public void testWithoutXForwarded() throws Exception {
+        doReturn("http").when(request).getScheme();
+        doReturn("localhost").when(request).getServerName();
+        doReturn(8080).when(request).getServerPort();
+        doReturn("/").when(request).getContextPath();
+        assertThat(UrlUtil.getBaseUrl(request)).isEqualTo("http://localhost:8080/");
+    }    
+
+    // Check base URL is using XForwarded headers
+    @Test
+    public void testWithXForwarded() throws Exception {
+        // basic request
+        doReturn("http").when(request).getScheme();
+        doReturn("localhost").when(request).getServerName();
+        doReturn(8080).when(request).getServerPort();
+        doReturn("/").when(request).getContextPath();
+
+        // XForwarded content
+        doReturn("https").when(request).getHeader("X-Forwarded-Proto");
+        doReturn("open-vsx.org").when(request).getHeader("X-Forwarded-Host");
+        doReturn("/openvsx").when(request).getHeader("X-Forwarded-Prefix");
+        assertThat(UrlUtil.getBaseUrl(request)).isEqualTo("https://open-vsx.org/openvsx/");
+    }    
+
+}