[JENKINS-43205][JENKINS-69006] Allow admins to configure a global default URL provider and always make external links go through /display/redirect

src/main/java/org/jenkinsci/plugins/displayurlapi/DefaultProviderGlobalConfiguration.java

@@ -0,0 +1,86 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2023 CloudBees, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package org.jenkinsci.plugins.displayurlapi;
+
+import edu.umd.cs.findbugs.annotations.CheckForNull;
+import hudson.Extension;
+import hudson.ExtensionList;
+import hudson.Util;
+import hudson.util.ListBoxModel;
+import java.util.Objects;
+import jenkins.model.GlobalConfiguration;
+import org.jenkinsci.plugins.displayurlapi.user.PreferredProviderUserProperty;
+import org.kohsuke.stapler.DataBoundSetter;
+
+@Extension
+public class DefaultProviderGlobalConfiguration extends GlobalConfiguration {
+
+    public DefaultProviderGlobalConfiguration() {
+        load();
+    }
+
+    private @CheckForNull String providerId;
+
+    public @CheckForNull String getProviderId() {
+        return providerId;
+    }
+
+    @DataBoundSetter
+    public void setProviderId(@CheckForNull String providerId) {
+        providerId = Util.fixEmptyAndTrim(providerId);
+        if (PreferredProviderUserProperty.ProviderOption.DEFAULT_OPTION.getId().equals(providerId)) {
+            providerId = null;
+        }
+        this.providerId = providerId;
+        save();
+    }
+
+    public @CheckForNull DisplayURLProvider getConfiguredProvider() {
+        if (providerId == null) {
+            return null;
+        }
+        return DisplayURLProvider.all().stream()
+            .filter(provider -> provider.getClass().getName().equals(providerId))
+            .findFirst()
+            .orElse(null);
+    }
+
+    public static DefaultProviderGlobalConfiguration get() {
+        return ExtensionList.lookupSingleton(DefaultProviderGlobalConfiguration.class);
+    }
+
+    public ListBoxModel doFillProviderIdItems() {
+        ListBoxModel items = new ListBoxModel();
+        for (PreferredProviderUserProperty.ProviderOption providerOption : PreferredProviderUserProperty.getAll()) {
+            ListBoxModel.Option option = new ListBoxModel.Option(
+                    providerOption.getName(),
+                    providerOption.getId(),
+                    Objects.equals(providerOption.getId(), providerId)
+            );
+            items.add(option);
+        }
+        return items;
+    }
+}

src/main/java/org/jenkinsci/plugins/displayurlapi/DisplayURLProvider.java

@@ -28,6 +28,10 @@ public abstract class DisplayURLProvider implements ExtensionPoint {
      * @return DisplayURLProvider
      */
     public static DisplayURLProvider get() {
+        // TODO: Would it not make more sense to return DisplayURLProviderImpl.INSTANCE unconditionally, always
+        // serving /display/redirect URLs that only get resolved when an actual user clicks on them? There is no
+        // guarantee that the current user (if any) is going to be the user who clicks the generated link so IDK why we
+        // take the current user's preferences into account here.
         DisplayURLProvider preferredProvider = getPreferredProvider();
         return preferredProvider != null ? preferredProvider : DisplayURLProviderImpl.INSTANCE;
     }
@@ -189,6 +193,8 @@ public static DisplayURLProvider getPreferredProvider() {
         if (prefProperty != null && prefProperty.getConfiguredProvider() != null) {
             return prefProperty.getConfiguredProvider();
         }
+        // Note that this logic means that `/display/redirect` links will never be produced when using the environment
+        // variable or system property, meaning that it effetively disables user preferences.
         String clazz = findClass();
         if (isNotEmpty(clazz)) {
             return ExtensionList.lookup(DisplayURLProvider.class).getDynamic(clazz);

src/main/java/org/jenkinsci/plugins/displayurlapi/actions/AbstractDisplayAction.java

@@ -7,6 +7,7 @@
 import java.util.function.Predicate;
 import org.apache.commons.lang.StringUtils;
 import org.jenkinsci.plugins.displayurlapi.ClassicDisplayURLProvider;
+import org.jenkinsci.plugins.displayurlapi.DefaultProviderGlobalConfiguration;
 import org.jenkinsci.plugins.displayurlapi.DisplayURLProvider;
 import org.jenkinsci.plugins.displayurlapi.user.PreferredProviderUserProperty;
 import org.kohsuke.stapler.StaplerRequest;
@@ -61,11 +62,16 @@ DisplayURLProvider lookupProvider(StaplerRequest req) {
     }
 
     DisplayURLProvider lookupProvider() {
+        // Check user preferences, then the global default (if any), then fall back to the extension with the highest ordinal value.
         PreferredProviderUserProperty prefProperty = getUserPreferredProviderProperty();
 
         if (prefProperty != null && prefProperty.getConfiguredProvider() != null) {
             return prefProperty.getConfiguredProvider();
         }
+        DisplayURLProvider globalProvider = DefaultProviderGlobalConfiguration.get().getConfiguredProvider();
+        if (globalProvider != null) {
+            return globalProvider;
+        }
         DisplayURLProvider displayURLProvider = DisplayURLProvider.getPreferredProvider();
         if (displayURLProvider == null) {
             ExtensionList<DisplayURLProvider> all = DisplayURLProvider.all();

src/main/java/org/jenkinsci/plugins/displayurlapi/user/PreferredProviderUserProperty.java

@@ -53,7 +53,7 @@ public DisplayURLProvider getConfiguredProvider() {
             .orElse(null);
     }
 
-    public List<ProviderOption> getAll() {
+    public static List<ProviderOption> getAll() {
         List<ProviderOption> options = DisplayURLProvider.all().stream()
             .map(input -> new ProviderOption(input.getClass().getName(), input.getDisplayName()))
             .collect(Collectors.toList());

src/main/java/org/jenkinsci/plugins/displayurlapi/user/PreferredProviderUserPropertyDescriptor.java

@@ -22,7 +22,7 @@ public UserProperty newInstance(User user) {
     public ListBoxModel doFillProviderIdItems() {
         ListBoxModel items = new ListBoxModel();
         PreferredProviderUserProperty property = PreferredProviderUserProperty.forCurrentUser();
-        for (ProviderOption providerOption : property.getAll()) {
+        for (ProviderOption providerOption : PreferredProviderUserProperty.getAll()) {
             ListBoxModel.Option option = new ListBoxModel.Option(
                     providerOption.getName(),
                     providerOption.getId(),

src/main/resources/org/jenkinsci/plugins/displayurlapi/DefaultProviderGlobalConfiguration/config.jelly

@@ -0,0 +1,9 @@
+<?jelly escape-by-default='true'?>
+<j:jelly xmlns:j="jelly:core" xmlns:st="jelly:stapler" xmlns:d="jelly:define" xmlns:l="/lib/layout"
+         xmlns:t="/lib/hudson" xmlns:f="/lib/form">
+    <f:section title="${%Default notification URL handler}">
+      <f:entry field="providerId">
+        <f:select/>
+      </f:entry>
+    </f:section>
+</j:jelly>

src/main/resources/org/jenkinsci/plugins/displayurlapi/DefaultProviderGlobalConfiguration/help-providerId.html

@@ -0,0 +1,4 @@
+<div>
+  Select the default handler when clicking links to Jenkins from notifications (e.g. Email, Slack, or GitHub).
+  Individual users can override this value as desired in their preferences.
+</div>

src/test/java/org/jenkinsci/plugins/displayurlapi/DisplayURLProviderTest.java

@@ -9,7 +9,9 @@
 import hudson.model.Run;
 import hudson.model.User;
 import hudson.security.ACL;
+import hudson.security.ACLContext;
 import jenkins.model.Jenkins;
+import org.jenkinsci.plugins.displayurlapi.actions.RunDisplayAction;
 import org.jenkinsci.plugins.displayurlapi.user.PreferredProviderUserProperty;
 import org.junit.Rule;
 import org.junit.Test;
@@ -270,6 +272,26 @@ public void decoration() throws Exception {
         assertEquals(DisplayURLProvider.get().getJobURL(project), environment.get("JOB_DISPLAY_URL"));
     }
 
+    @Test
+    public void providerConfigurationPrecedence() throws Exception {
+        rule.jenkins.setSecurityRealm(rule.createDummySecurityRealm());
+        // user1 does not have a preference, but user2 does.
+        User user1 = User.getById("user1", true);
+        User user2 = User.getById("user2", true);
+        user2.addProperty(new PreferredProviderUserProperty(ClassicDisplayURLProvider.class.getName()));
+        // admin configures TestUserDisplayURLProvider as the default provider.
+        DefaultProviderGlobalConfiguration.get().setProviderId(TestUserDisplayURLProvider.class.getName());
+        FreeStyleProject p = rule.createFreeStyleProject();
+        Run<?, ?> b = rule.buildAndAssertSuccess(p);
+        RunDisplayAction action = b.getAction(RunDisplayAction.class);
+        try (ACLContext unused = ACL.as2(user1.impersonate2())) {
+            assertEquals(rule.getURL() + b.getUrl() + TestUserDisplayURLProvider.EXTRA_CONTENT_IN_URL, action.getDisplayUrl());
+        }
+        try (ACLContext unused = ACL.as2(user2.impersonate2())) {
+            assertEquals(rule.getURL() + b.getUrl(), action.getDisplayUrl());
+        }
+    }
+
     @TestExtension("decoration")
     public static class DisplayURLDecoratorImpl extends DisplayURLDecorator {
         @NonNull