Fix JCasC startup crash caused by broken ManagementLink extensions (#2807)

Author: somiljain2006

plugin/src/main/java/io/jenkins/plugins/casc/RootElementConfigurator.java

@@ -6,6 +6,8 @@
 import io.jenkins.plugins.casc.impl.configurators.GlobalConfigurationCategoryConfigurator;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import jenkins.model.GlobalConfigurationCategory;
 import jenkins.model.Jenkins;
 
@@ -16,6 +18,8 @@
  */
 public interface RootElementConfigurator<T> extends Configurator<T> {
 
+    Logger LOGGER = Logger.getLogger(RootElementConfigurator.class.getName());
+
     static List<RootElementConfigurator> all() {
         final Jenkins jenkins = Jenkins.get();
         List<RootElementConfigurator> configurators =
@@ -26,10 +30,20 @@ static List<RootElementConfigurator> all() {
         }
 
         for (ManagementLink link : ManagementLink.all()) {
-            final String name = link.getUrlName();
-            final Descriptor descriptor = Jenkins.get().getDescriptor(name);
-            if (descriptor != null) {
-                configurators.add(new DescriptorConfigurator(descriptor));
+            try {
+                final String name = link.getUrlName();
+                if (name != null && !name.isEmpty()) {
+                    final Descriptor descriptor = Jenkins.get().getDescriptor(name);
+                    if (descriptor != null) {
+                        configurators.add(new DescriptorConfigurator(descriptor));
+                    }
+                }
+            } catch (Exception | LinkageError e) {
+                LOGGER.log(
+                        Level.WARNING,
+                        "Failed to load configuration for ManagementLink: "
+                                + link.getClass().getName() + ". Skipping.",
+                        e);
             }
         }
 

plugin/src/test/java/io/jenkins/plugins/casc/RootElementConfiguratorTest.java

@@ -0,0 +1,65 @@
+package io.jenkins.plugins.casc;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+
+import hudson.model.ManagementLink;
+import java.util.List;
+import org.junit.Rule;
+import org.junit.Test;
+import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.TestExtension;
+
+public class RootElementConfiguratorTest {
+
+    @Rule
+    public JenkinsRule j = new JenkinsRule();
+
+    @Test
+    @SuppressWarnings("rawtypes")
+    public void shouldSurviveBrokenManagementLink() {
+        List<RootElementConfigurator> configurators = RootElementConfigurator.all();
+
+        assertNotNull("Configurators list should not be null", configurators);
+        assertFalse("Should load at least some standard configurators", configurators.isEmpty());
+    }
+
+    @TestExtension("shouldSurviveBrokenManagementLink")
+    @SuppressWarnings("unused")
+    public static class BrokenManagementLink extends ManagementLink {
+
+        @Override
+        public String getIconFileName() {
+            return null;
+        }
+
+        @Override
+        public String getDisplayName() {
+            return "Broken Cluster Stats Link";
+        }
+
+        @Override
+        public String getUrlName() {
+            throw new IllegalStateException("cannot call getRootUrlFromRequest from outside a request handling thread");
+        }
+    }
+
+    @TestExtension("shouldSurviveBrokenManagementLink")
+    @SuppressWarnings("unused")
+    public static class EmptyStringManagementLink extends ManagementLink {
+        @Override
+        public String getIconFileName() {
+            return null;
+        }
+
+        @Override
+        public String getDisplayName() {
+            return "Empty Link";
+        }
+
+        @Override
+        public String getUrlName() {
+            return "";
+        }
+    }
+}