Adding the reload job functionality

changelog.html

@@ -58,6 +58,8 @@ Upcoming changes</a>
   <li class=rfe>
     Access through API token and SSH key login now fully retains group memberships.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-20064">issue 20064</a>)
+  <li class=rfe>
+    Job can be reloaded individually from disk with "job/FOO/reload" URL or "reload-job" CLI command
 </ul>
 </div><!--=TRUNK-END=-->
 

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

@@ -586,6 +586,7 @@ public abstract class AbstractItem extends Actionable implements Item, HttpDelet
             }
 
             // try to reflect the changes by reloading
+            doReload();
             new XmlFile(Items.XSTREAM, out.getTemporaryFile()).unmarshal(this);
             Items.whileUpdatingByXml(new Callable<Void,IOException>() {
                 @Override public Void call() throws IOException {
@@ -603,6 +604,34 @@ public abstract class AbstractItem extends Actionable implements Item, HttpDelet
         }
     }
 
+    /**
+     * Reloads this job from the disk.
+     *
+     * Exposed through CLI as well.
+     *
+     * TODO: think about exposing this to UI
+     *
+     * @since 1.556
+     */
+    @CLIMethod(name="reload-job")
+    @RequirePOST
+    public void doReload() throws IOException {
+        checkPermission(CONFIGURE);
+
+        // try to reflect the changes by reloading
+        getConfigFile().unmarshal(this);
+        Items.whileUpdatingByXml(new Callable<Void, IOException>() {
+            @Override
+            public Void call() throws IOException {
+                onLoad(getParent(), getRootDir().getName());
+                return null;
+            }
+        });
+        Jenkins.getInstance().rebuildDependencyGraphAsync();
+
+        SaveableListener.fireOnChange(this, getConfigFile());
+    }
+
 
     /* (non-Javadoc)
      * @see hudson.model.AbstractModelObject#getSearchName()

core/src/main/resources/hudson/model/Messages.properties

@@ -91,6 +91,7 @@ BallColor.Unstable=Unstable
 
 CLI.clear-queue.shortDescription=Clears the build queue.
 CLI.delete-job.shortDescription=Deletes a job.
+CLI.reload-job.shortDescription=Reloads this job from disk.
 CLI.disable-job.shortDescription=Disables a job.
 CLI.enable-job.shortDescription=Enables a job.
 CLI.delete-node.shortDescription=Deletes a node.

test/src/test/groovy/hudson/model/AbstractItemTest.groovy

+package hudson.model
+
+import org.junit.Rule
+import org.junit.Test
+import org.jvnet.hudson.test.JenkinsRule
+
+/**
+ *
+ *
+ * @author Kohsuke Kawaguchi
+ */
+class AbstractItemTest {
+    @Rule
+    public JenkinsRule j = new JenkinsRule()
+
+    /**
+     * Tests the reload functionality
+     */
+    @Test
+    void reload() {
+        def jenkins = j.jenkins;
+        def p = jenkins.createProject(FreeStyleProject.class,"foo");
+        p.description = "Hello World";
+
+        def b = j.assertBuildStatusSuccess(p.scheduleBuild2(0))
+        b.description = "This is my build"
+
+        // update on disk representation
+        def f = p.configFile.file
+        f.text = f.text.replaceAll("Hello World","Good Evening");
+
+        // reload away
+        p.doReload()
+
+        assert p.description == "Good Evening";
+
+        def b2 = p.getBuildByNumber(1)
+
+        assert !b.is(b2);   // should be different object
+        assert b.description == b2.description   // but should have the same properties
+    }
+}