[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

@@ -1,5 +1,6 @@
 package org.jenkinsci.plugins.displayurlapi;
 
+import edu.umd.cs.findbugs.annotations.CheckForNull;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
 import hudson.ExtensionList;
@@ -19,7 +20,16 @@
  * Generates URLs for well known UI locations for use in notifications (e.g. mailer, HipChat, Slack,
  * IRC, etc) Extensible to allow plugins to override common URLs (e.g. Blue Ocean or another future
  * secondary UI)
+ *
+ * <p>Implementations should generally extend {@link ClassicDisplayURLProvider} and delegate to it for unsupported
+ * builds instead of extending this class directly.
  */
+/* TODO: This API is awkward to implement. All providers must return a non-null value for all URLs, meaning that in
+   practice they all need to delegate to ClassicDisplayURLProvider. Ideally, the API would allow providers to return
+   null to indicate that they do not support a particular build/job, and we would loop over all providers in a
+   user-defined order looking for the first one that returns a non-null URL, which would allow providers which handle
+   distinct job types to coexist.
+*/
 public abstract class DisplayURLProvider implements ExtensionPoint {
 
     /**
@@ -28,8 +38,7 @@ public abstract class DisplayURLProvider implements ExtensionPoint {
      * @return DisplayURLProvider
      */
     public static DisplayURLProvider get() {
-        DisplayURLProvider preferredProvider = getPreferredProvider();
-        return preferredProvider != null ? preferredProvider : DisplayURLProviderImpl.INSTANCE;
+        return DisplayURLProviderImpl.INSTANCE;
     }
 
     /**
@@ -41,13 +50,30 @@ public static ExtensionList<DisplayURLProvider> all() {
         return ExtensionList.lookup(DisplayURLProvider.class);
     }
 
+    /**
+     * Returns the singleton instance of the {@link ClassicDisplayURLProvider} extension.
+     *
+     * <p>If you want to retrieve the configured default provider, use {@link getConfiguredDefault}.
+     */
     public static DisplayURLProvider getDefault() {
-        DisplayURLProvider defaultProvider = getPreferredProvider();
-        if (defaultProvider == null) {
-            defaultProvider = ExtensionList.lookup(DisplayURLProvider.class)
+        return ExtensionList.lookup(DisplayURLProvider.class)
                 .get(ClassicDisplayURLProvider.class);
+    }
+
+    /**
+     * Returns the {@link DisplayURLProvider} that has been configured as a global default, either via {@link DefaultProviderGlobalConfiguration},
+     * or by environment variable or system property, or {@code null} if there no configured default.
+     */
+    public static @CheckForNull DisplayURLProvider getConfiguredDefault() {
+        DisplayURLProvider guiProvider = DefaultProviderGlobalConfiguration.get().getConfiguredProvider();
+        if (guiProvider != null) {
+            return guiProvider;
         }
-        return defaultProvider;
+        String clazz = findClass();
+        if (isNotEmpty(clazz)) {
+            return ExtensionList.lookup(DisplayURLProvider.class).getDynamic(clazz);
+        }
+        return null;
     }
 
     /**
@@ -182,6 +208,12 @@ private static String findClass() {
         return clazz;
     }
 
+    /**
+     * @deprecated If you need the default implementation for producing display URLs, use {@link #get}.
+     * If you need a fallback provider for your implementation of {@link DisplayURLProvider} that will work for all jobs and runs, use {@link #getDefault}.
+     * Actual redirect resolution incorporating user preferences should be left to {@link AbstractDisplayAction#lookupProvider}
+     */
+    @Deprecated
     @Nullable
     public static DisplayURLProvider getPreferredProvider() {
         PreferredProviderUserProperty prefProperty = getUserPreferredProviderProperty();
@@ -203,5 +235,5 @@ public static PreferredProviderUserProperty getUserPreferredProviderProperty() {
     }
 
     private static final String JENKINS_DISPLAYURL_PROVIDER_ENV = "JENKINS_DISPLAYURL_PROVIDER";
-    private static final String JENKINS_DISPLAYURL_PROVIDER_PROP = "jenkins.displayurl.provider";
+    static final String JENKINS_DISPLAYURL_PROVIDER_PROP = "jenkins.displayurl.provider";
 }

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

@@ -61,20 +61,27 @@ DisplayURLProvider lookupProvider(StaplerRequest req) {
     }
 
     DisplayURLProvider lookupProvider() {
+        // We pick the first non-null option in this order:
+        // 1: PreferredProviderUserProperty (user preference)
+        // 2: DefaultProviderGlobalConfiguration (GUI-configured global default)
+        // 3: Env var/system properties defined in DisplayURLProvider (global default)
+        // 4: The DisplayUrlProvider extension with the highest ordinal value that is not an instance of ClassicDisplayURLProvider
+        // 5. ClassicDisplayURLProvider
         PreferredProviderUserProperty prefProperty = getUserPreferredProviderProperty();
 
         if (prefProperty != null && prefProperty.getConfiguredProvider() != null) {
             return prefProperty.getConfiguredProvider();
         }
-        DisplayURLProvider displayURLProvider = DisplayURLProvider.getPreferredProvider();
-        if (displayURLProvider == null) {
-            ExtensionList<DisplayURLProvider> all = DisplayURLProvider.all();
-            displayURLProvider = all.stream()
+        DisplayURLProvider globalProvider = DisplayURLProvider.getConfiguredDefault();
+        if (globalProvider != null) {
+            return globalProvider;
+        }
+        ExtensionList<DisplayURLProvider> all = DisplayURLProvider.all();
+        DisplayURLProvider displayURLProvider = all.stream()
                 .filter(
                     ((Predicate<DisplayURLProvider>) ClassicDisplayURLProvider.class::isInstance)
                         .negate())
                 .findFirst().orElse(DisplayURLProvider.getDefault());
-        }
         return displayURLProvider;
     }
 

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>