[engine] Fix problem with follow parameter when api prefix with version removed wrongly

backend/manager/modules/restapi/jaxrs/src/main/java/org/ovirt/engine/api/restapi/resource/ResourceLocator.java

@@ -2,6 +2,8 @@
 
 import java.lang.reflect.Method;
 import java.util.Arrays;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import org.ovirt.engine.api.rsdl.ServiceTreeCrawler;
 import org.ovirt.engine.api.rsdl.ServiceTreeNode;
@@ -13,6 +15,8 @@
  */
 public class ResourceLocator {
 
+    private static final Pattern ULR_VERSION_PART_PATTERN = Pattern.compile("/api/(v\\d+/)?");
+
     private static ResourceLocator instance;
 
     private ResourceLocator() {
@@ -58,12 +62,15 @@ public BaseBackendResource locateResource(String href) throws Exception {
      *   http://localhost:8080/ovirt-engine/api/
      * Remain with:
      *   datacenters/1034e9ba-c1a4-442c-8bc9-f7c1c997652b
+     *
+     * Api definition with version also can be truncated (e.g. /api/v3/ or /api/v4/)
      */
-    private String removePrefix(String href) {
-        int index = href.indexOf("/api/");
-        if (index>0) {
-            href = href.substring(index+5);
+    static String removePrefix(String href) {
+        Matcher matcher = ULR_VERSION_PART_PATTERN.matcher(href);
+        if (matcher.find()) {
+            href = href.substring(matcher.end());
         }
+
         return href;
     }
 }

backend/manager/modules/restapi/jaxrs/src/test/java/org/ovirt/engine/api/restapi/resource/ResourceLocatorTest.java

@@ -0,0 +1,42 @@
+package org.ovirt.engine.api.restapi.resource;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.stream.Stream;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+class ResourceLocatorTest {
+
+    @ParameterizedTest
+    @MethodSource("providerUrlsToCheckSuffixExtraction")
+    void testResourceLocatorGetPrefix(String source, String expectedResult) {
+        assertEquals(expectedResult, ResourceLocator.removePrefix(source));
+    }
+
+    private static Stream<Arguments> providerUrlsToCheckSuffixExtraction() {
+        var basePart = "http://localhost:8080/ovirt-engine";
+        var suffix = "datacenters/1034e9ba-c1a4-442c-8bc9-f7c1c997652b";
+
+        return Stream.of(
+                Arguments.of(
+                        basePart + "/api/v12/" + suffix,
+                        suffix
+                ),
+                Arguments.of(
+                        basePart + "/api/" + suffix,
+                        suffix
+                ),
+                Arguments.of(
+                        basePart + "/api/v4/" + suffix,
+                        suffix
+                ),
+                Arguments.of( // Without pattern, method should return the same string.
+                        basePart + "/" + suffix,
+                        basePart + "/" + suffix
+                )
+        );
+    }
+}