[JENKINS-60577] - Prevent the RSS feed in Computer page from returning an error 404 (#4411)

* [JENKINS-60577] Rss Latest Builds for Computer

* [JENKINS-60577] Missing javadoc

* [JENKINS-60577] Add builds from the computer

* Update core/src/main/java/hudson/model/Computer.java

* Apply suggestions from code review
Co-Authored-By: NOleg Nenashev <o.v.nenashev@gmail.com>

* [JENKINS-60577] Document limitation to AbstractProject

* [JENKINS-60577] Restrict the RSS methods in Computer
Co-authored-by: NOleg Nenashev <o.v.nenashev@gmail.com>

core/src/main/java/hudson/model/Computer.java

@@ -1368,16 +1368,36 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
 // UI
 //
 //
+    @Restricted(DoNotUse.class)
     public void doRssAll( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
-        rss(req, rsp, " all builds", getBuilds());
+        RSS.rss(req, rsp, getDisplayName() + " all builds", getUrl(), getBuilds());
     }
 
+    @Restricted(DoNotUse.class)
     public void doRssFailed(StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
-        rss(req, rsp, " failed builds", getBuilds().failureOnly());
+        RSS.rss(req, rsp, getDisplayName() + " failed builds", getUrl(), getBuilds().failureOnly());
     }
-    private void rss(StaplerRequest req, StaplerResponse rsp, String suffix, RunList runs) throws IOException, ServletException {
-        RSS.forwardToRss(getDisplayName() + suffix, getUrl(),
-                runs.newBuilds(), Run.FEED_ADAPTER, req, rsp);
+
+    /**
+     * Retrieve the RSS feed for the last build for each project executed in this computer.
+     * Only the information from {@link AbstractProject} is displayed since there isn't a proper API to gather
+     * information about the node where the builds are executed for other sorts of projects such as Pipeline
+     * @since TODO
+     */
+    @Restricted(DoNotUse.class)
+    public void doRssLatest( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
+        final List<Run> lastBuilds = new ArrayList<>();
+        for (AbstractProject<?, ?> p : Jenkins.get().allItems(AbstractProject.class)) {
+            if (p.getLastBuild() != null) {
+                for (AbstractBuild<?, ?> b = p.getLastBuild(); b != null; b = b.getPreviousBuild()) {
+                    if (b.getBuiltOn() == getNode()) {
+                        lastBuilds.add(b);
+                        break;
+                    }
+                }
+            }
+        }
+        RSS.rss(req, rsp, getDisplayName() + " last builds only", getUrl(), RunList.fromRuns(lastBuilds));
     }
 
     @RequirePOST

core/src/main/java/hudson/model/Job.java

@@ -1566,18 +1566,12 @@ public abstract class Job<JobT extends Job<JobT, RunT>, RunT extends Run<JobT, R
 
     public void doRssAll(StaplerRequest req, StaplerResponse rsp)
             throws IOException, ServletException {
-        rss(req, rsp, " all builds", getBuilds());
+        RSS.rss(req, rsp, getDisplayName() + " all builds", getUrl(), getBuilds().newBuilds());
     }
 
     public void doRssFailed(StaplerRequest req, StaplerResponse rsp)
             throws IOException, ServletException {
-        rss(req, rsp, " failed builds", getBuilds().failureOnly());
-    }
-
-    private void rss(StaplerRequest req, StaplerResponse rsp, String suffix,
-            RunList runs) throws IOException, ServletException {
-        RSS.forwardToRss(getDisplayName() + suffix, getUrl(), runs.newBuilds(),
-                Run.FEED_ADAPTER, req, rsp);
+        RSS.rss(req, rsp, getDisplayName() + " failed builds", getUrl(), getBuilds().failureOnly().newBuilds());
     }
 
     /**

core/src/main/java/hudson/model/RSS.java

@@ -24,6 +24,7 @@
 package hudson.model;
 
 import hudson.FeedAdapter;
+import hudson.util.RunList;
 import jenkins.model.Jenkins;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.StaplerResponse;
@@ -90,4 +91,37 @@ public final class RSS {
 
         req.getView(Jenkins.get(),"/hudson/"+flavor+".jelly").forward(req,rsp);
     }
+
+    /**
+     * Sends the RSS feed to the client using a default feed adapter.
+     *
+     * @param title
+     *      Title of the feed.
+     * @param url
+     *      URL of the model object that owns this feed. Relative to the context root.
+     * @param runList
+     *      Entries to be listed in the RSS feed.
+     * @since TODO
+     */
+    public static void rss(StaplerRequest req, StaplerResponse rsp, String title, String url, RunList runList) throws IOException, ServletException {
+        rss(req, rsp, title, url, runList, null);
+    }
+
+    /**
+     * Sends the RSS feed to the client using a specific feed adapter.
+     *
+     * @param title
+     *      Title of the feed.
+     * @param url
+     *      URL of the model object that owns this feed. Relative to the context root.
+     * @param runList
+     *      Entries to be listed in the RSS feed.
+     * @param feedAdapter
+     *      Controls how to render entries to RSS.
+     * @since TODO
+     */
+    public static void rss(StaplerRequest req, StaplerResponse rsp, String title, String url, RunList runList, FeedAdapter<Run> feedAdapter) throws IOException, ServletException {
+        final FeedAdapter<Run> feedAdapter_ = feedAdapter == null ? Run.FEED_ADAPTER : feedAdapter;
+        forwardToRss(title, url, runList, feedAdapter_, req, rsp);
+    }
 }

core/src/main/java/hudson/model/User.java

@@ -872,11 +872,11 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
     }
 
     public void doRssAll(StaplerRequest req, StaplerResponse rsp) throws IOException, ServletException {
-        rss(req, rsp, " all builds", getBuilds(), Run.FEED_ADAPTER);
+        RSS.rss(req, rsp, getDisplayName() + " all builds", getUrl(), getBuilds().newBuilds());
     }
 
     public void doRssFailed(StaplerRequest req, StaplerResponse rsp) throws IOException, ServletException {
-        rss(req, rsp, " regression builds", getBuilds().regressionOnly(), Run.FEED_ADAPTER);
+        RSS.rss(req, rsp, getDisplayName() + " regression builds", getUrl(), getBuilds().regressionOnly());
     }
 
     public void doRssLatest(StaplerRequest req, StaplerResponse rsp) throws IOException, ServletException {
@@ -892,12 +892,7 @@ public class User extends AbstractModelObject implements AccessControlled, Descr
         // historically these have been reported sorted by project name, we switched to the lazy iteration
         // so we only have to sort the sublist of runs rather than the full list of irrelevant projects
         lastBuilds.sort((o1, o2) -> Items.BY_FULL_NAME.compare(o1.getParent(), o2.getParent()));
-        rss(req, rsp, " latest build", RunList.fromRuns(lastBuilds), Run.FEED_ADAPTER_LATEST);
-    }
-
-    private void rss(StaplerRequest req, StaplerResponse rsp, String suffix, RunList runs, FeedAdapter adapter)
-            throws IOException, ServletException {
-        RSS.forwardToRss(getDisplayName() + suffix, getUrl(), runs.newBuilds(), adapter, req, rsp);
+        RSS.rss(req, rsp, getDisplayName() + " latest build", getUrl(), RunList.fromRuns(lastBuilds), Run.FEED_ADAPTER_LATEST);
     }
 
     @Override

core/src/main/java/hudson/model/View.java

@@ -1144,11 +1144,11 @@ public abstract class View extends AbstractModelObject implements AccessControll
     }
 
     public void doRssAll( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
-        rss(req, rsp, " all builds", getBuilds());
+        RSS.rss(req, rsp, getDisplayName() + " all builds", getUrl(), getBuilds().newBuilds());
     }
 
     public void doRssFailed( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
-        rss(req, rsp, " failed builds", getBuilds().failureOnly());
+        RSS.rss(req, rsp, getDisplayName() + " failed builds", getUrl(), getBuilds().failureOnly().newBuilds());
     }
     
     public RunList getBuilds() {
@@ -1159,11 +1159,6 @@ public abstract class View extends AbstractModelObject implements AccessControll
         return new BuildTimelineWidget(getBuilds());
     }
 
-    private void rss(StaplerRequest req, StaplerResponse rsp, String suffix, RunList runs) throws IOException, ServletException {
-        RSS.forwardToRss(getDisplayName()+ suffix, getUrl(),
-            runs.newBuilds(), Run.FEED_ADAPTER, req, rsp );
-    }
-
     public void doRssLatest( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
         List<Run> lastBuilds = new ArrayList<>();
         for (TopLevelItem item : getItems()) {
@@ -1173,8 +1168,7 @@ public abstract class View extends AbstractModelObject implements AccessControll
                 if(lb!=null)    lastBuilds.add(lb);
             }
         }
-        RSS.forwardToRss(getDisplayName()+" last builds only", getUrl(),
-            lastBuilds, Run.FEED_ADAPTER_LATEST, req, rsp );
+        RSS.rss(req, rsp, getDisplayName() + " last builds only", getUrl(), RunList.fromRuns(lastBuilds), Run.FEED_ADAPTER_LATEST);
     }
 
     /**

test/src/test/java/hudson/model/RSSTest.java

@@ -31,6 +31,10 @@ import org.jvnet.hudson.test.JenkinsRule;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.containsString;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
@@ -43,7 +47,7 @@ public class RSSTest {
     @Test
     @Issue("JENKINS-59167")
     public void absoluteURLsPresentInRSS_evenWithoutRootUrlSetup() throws Exception {
-        XmlPage page = getRssPage();
+        XmlPage page = getRssAllPage();
         NodeList allLinks = page.getXmlDocument().getElementsByTagName("link");
 
         assertEquals(1, allLinks.getLength());
@@ -52,14 +56,14 @@ public class RSSTest {
         FreeStyleProject p = j.createFreeStyleProject();
         j.assertBuildStatusSuccess(p.scheduleBuild2(0));
 
-        page = getRssPage();
+        page = getRssAllPage();
         allLinks = page.getXmlDocument().getElementsByTagName("link");
 
         assertEquals(2, allLinks.getLength());
         assertAllRSSLinksContainRootUrl(allLinks);
     }
 
-    private XmlPage getRssPage() throws Exception {
+    private XmlPage getRssAllPage() throws Exception {
         return (XmlPage) j.createWebClient().goTo("rssAll?flavor=rss20", "text/xml");
     }
 
@@ -74,7 +78,7 @@ public class RSSTest {
     @Test
     @Issue("JENKINS-59167")
     public void absoluteURLsPresentInAtom_evenWithoutRootUrlSetup() throws Exception {
-        XmlPage page = getAtomPage();
+        XmlPage page = getRssAllAtomPage();
         NodeList allLinks = page.getXmlDocument().getElementsByTagName("link");
 
         assertEquals(1, allLinks.getLength());
@@ -83,14 +87,14 @@ public class RSSTest {
         FreeStyleProject p = j.createFreeStyleProject();
         j.assertBuildStatusSuccess(p.scheduleBuild2(0));
 
-        page = getAtomPage();
+        page = getRssAllAtomPage();
         allLinks = page.getXmlDocument().getElementsByTagName("link");
 
         assertEquals(2, allLinks.getLength());
         assertAllAtomLinksContainRootUrl(allLinks);
     }
 
-    private XmlPage getAtomPage() throws Exception {
+    private XmlPage getRssAllAtomPage() throws Exception {
         return (XmlPage) j.createWebClient().goTo("rssAll", "application/atom+xml");
     }
 
@@ -102,4 +106,51 @@ public class RSSTest {
             assertThat(url, containsString(j.getURL().toString()));
         }
     }
+
+    @Issue("JENKINS-60577")
+    @Test
+    public void latestBuilds() throws Exception {
+        XmlPage page = getRssLatestPage();
+        NodeList allLinks = page.getXmlDocument().getElementsByTagName("link");
+
+        assertEquals(1, allLinks.getLength());
+
+        FreeStyleProject p = j.createFreeStyleProject("test1");
+        j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+        j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+
+        p = j.createFreeStyleProject("test2");
+        j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+        j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+        j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+
+        page = getRssLatestPage();
+        allLinks = page.getXmlDocument().getElementsByTagName("link");
+
+        assertEquals(3, allLinks.getLength());
+        assertLatestRSSLinks(allLinks);
+
+        page = getRssAllPage();
+        allLinks = page.getXmlDocument().getElementsByTagName("link");
+        assertEquals(6, allLinks.getLength());
+    }
+
+    private XmlPage getRssLatestPage() throws Exception {
+        return (XmlPage) j.createWebClient().goTo("rssLatest?flavor=rss20", "text/xml");
+    }
+
+    private void assertLatestRSSLinks(NodeList allLinks) throws Exception {
+        List<String> urls = new ArrayList<>(allLinks.getLength());
+        for (int i = 0; i < allLinks.getLength(); i++) {
+            Node item = allLinks.item(i);
+            String url = item.getTextContent();
+            urls.add(url);
+        }
+
+        assertThat(urls, containsInAnyOrder(
+                j.getURL().toString(),
+                j.getURL().toString() + "job/test1/2/",
+                j.getURL().toString() + "job/test2/3/"
+        ));
+    }
 }