Add configuration to allow deferring the initial Deployment until after Server is started

jetty-deploy/pom.xml

@@ -59,5 +59,9 @@
       <artifactId>jetty-test-helper</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.awaitility</groupId>
+      <artifactId>awaitility</artifactId>
+    </dependency>
   </dependencies>
 </project>

jetty-deploy/src/main/config/etc/jetty-deploy.xml

@@ -53,6 +53,7 @@
                   </Default>
                 </Property>
               </Set>
+              <Set name="deferInitialScan"><Property name="jetty.deploy.deferInitialScan" default="false"/></Set>
               <Set name="scanInterval"><Property name="jetty.deploy.scanInterval" default="1"/></Set>
               <Set name="extractWars"><Property name="jetty.deploy.extractWars" default="true"/></Set>
               <Set name="configurationManager">

jetty-deploy/src/main/config/modules/deploy.mod

@@ -20,8 +20,15 @@ etc/jetty-deploy.xml
 # Defaults Descriptor for all deployed webapps
 # jetty.deploy.defaultsDescriptorPath=${jetty.base}/etc/webdefault.xml
 
+# Defer Initial Scan
+# true to have the initial scan deferred until the Server component is started.
+#      Note: deploy failures do not fail server startup in a deferred initial scan mode.
+# false (default) to have initial scan occur as normal.
+# jetty.deploy.deferInitialScan=false
+
 # Monitored directory scan period (seconds)
 # jetty.deploy.scanInterval=1
 
 # Whether to extract *.war files
 # jetty.deploy.extractWars=true
+

jetty-deploy/src/main/java/org/eclipse/jetty/deploy/providers/ScanningAppProvider.java

@@ -27,11 +27,13 @@
 import org.eclipse.jetty.deploy.App;
 import org.eclipse.jetty.deploy.AppProvider;
 import org.eclipse.jetty.deploy.DeploymentManager;
+import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.util.Scanner;
 import org.eclipse.jetty.util.annotation.ManagedAttribute;
 import org.eclipse.jetty.util.annotation.ManagedObject;
 import org.eclipse.jetty.util.annotation.ManagedOperation;
 import org.eclipse.jetty.util.component.ContainerLifeCycle;
+import org.eclipse.jetty.util.component.LifeCycle;
 import org.eclipse.jetty.util.resource.Resource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -49,6 +51,7 @@ public abstract class ScanningAppProvider extends ContainerLifeCycle implements
     private int _scanInterval = 10;
     private Scanner _scanner;
     private boolean _useRealPaths;
+    private boolean _deferInitialScan = false;
 
     private final Scanner.DiscreteListener _scannerListener = new Scanner.DiscreteListener()
     {
@@ -152,9 +155,30 @@ protected void doStart() throws Exception
         _scanner.setReportDirs(true);
         _scanner.setScanDepth(1); //consider direct dir children of monitored dir
         _scanner.addListener(_scannerListener);
-
+        _scanner.setReportExistingFilesOnStartup(true);
+        _scanner.setAutoStartScanning(!_deferInitialScan);
         addBean(_scanner);
 
+        if (_deferInitialScan)
+        {
+            // Setup listener to wait for Server in STARTED state, which
+            // triggers the first scan of the monitored directories
+            getDeploymentManager().getServer().addEventListener(
+                new LifeCycle.Listener()
+                {
+                    @Override
+                    public void lifeCycleStarted(LifeCycle event)
+                    {
+                        if (event instanceof Server)
+                        {
+                            if (LOG.isDebugEnabled())
+                                LOG.debug("Triggering Deferred Scan of {}", _monitored);
+                            _scanner.startScanning();
+                        }
+                    }
+                });
+        }
+
         super.doStart();
     }
 
@@ -296,6 +320,34 @@ public void setMonitoredDirectories(Collection<String> directories)
         }
     }
 
+    /**
+     * Test if initial scan should be deferred.
+     *
+     * @return true if initial scan is deferred, false to have initial scan occur on startup of ScanningAppProvider.
+     */
+    public boolean isDeferInitialScan()
+    {
+        return _deferInitialScan;
+    }
+
+    /**
+     * Flag to control initial scan behavior.
+     *
+     * <ul>
+     *     <li>{@code true} - to have initial scan deferred until the {@link Server} component
+     *     has reached it's STARTED state.<br>
+     *     Note: any failures in a deploy will not fail the Server startup in this mode.</li>
+     *     <li>{@code false} - (default value) to have initial scan occur as normal on
+     *     ScanningAppProvider startup.</li>
+     * </ul>
+     *
+     * @param defer true to defer initial scan, false to have initial scan occur on startup of ScanningAppProvider.
+     */
+    public void setDeferInitialScan(boolean defer)
+    {
+        _deferInitialScan = defer;
+    }
+
     public void setScanInterval(int scanInterval)
     {
         _scanInterval = scanInterval;

jetty-deploy/src/test/java/org/eclipse/jetty/deploy/providers/WebAppProviderTest.java

@@ -17,28 +17,31 @@
 import java.nio.file.FileSystemException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.time.Duration;
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.eclipse.jetty.deploy.AppProvider;
+import org.eclipse.jetty.deploy.DeploymentManager;
 import org.eclipse.jetty.deploy.test.XmlConfiguredJetty;
 import org.eclipse.jetty.server.Handler;
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.handler.ContextHandler;
-import org.eclipse.jetty.server.handler.HandlerCollection;
 import org.eclipse.jetty.toolchain.test.MavenTestingUtils;
 import org.eclipse.jetty.toolchain.test.jupiter.WorkDir;
 import org.eclipse.jetty.toolchain.test.jupiter.WorkDirExtension;
 import org.eclipse.jetty.util.IO;
 import org.eclipse.jetty.util.resource.Resource;
 import org.eclipse.jetty.webapp.WebAppContext;
 import org.junit.jupiter.api.AfterEach;
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.EnabledOnOs;
 import org.junit.jupiter.api.extension.ExtendWith;
 
+import static org.awaitility.Awaitility.await;
+import static org.hamcrest.Matchers.is;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -52,8 +55,7 @@ public class WebAppProviderTest
     private static XmlConfiguredJetty jetty;
     private boolean symlinkSupported = false;
 
-    @BeforeEach
-    public void setupEnvironment() throws Exception
+    private void startEnvironment() throws Exception
     {
         Path p = testdir.getEmptyPathDir();
         jetty = new XmlConfiguredJetty(p);
@@ -97,8 +99,9 @@ public void teardownEnvironment() throws Exception
     }
 
     @Test
-    public void testStartupContext()
+    public void testStartupContext() throws Exception
     {
+        startEnvironment();
         assumeTrue(symlinkSupported);
 
         // Check Server for Handlers
@@ -115,8 +118,9 @@ public void testStartupContext()
     }
 
     @Test
-    public void testStartupSymlinkContext()
+    public void testStartupSymlinkContext() throws Exception
     {
+        startEnvironment();
         assumeTrue(symlinkSupported);
 
         // Check for path
@@ -139,17 +143,11 @@ public void testStartupSymlinkContext()
     @EnabledOnOs({LINUX})
     public void testWebappSymlinkDir() throws Exception
     {
-        jetty.stop(); //reconfigure jetty
-
-        testdir.ensureEmpty();
-
         jetty = new XmlConfiguredJetty(testdir.getEmptyPathDir());
         jetty.addConfiguration("jetty.xml");
         jetty.addConfiguration("jetty-http.xml");
         jetty.addConfiguration("jetty-deploy-wars.xml");
 
-        assumeTrue(symlinkSupported);
-
         //delete the existing webapps directory
         File webapps = jetty.getJettyDir("webapps");
         assertTrue(IO.delete(webapps));
@@ -159,14 +157,25 @@ public void testWebappSymlinkDir() throws Exception
         Files.createDirectory(x.toPath());
 
         //Put a webapp into it
-        File srcDir = MavenTestingUtils.getTestResourceDir("webapps");
+        Path srcDir = MavenTestingUtils.getTestResourcePathDir("webapps");
         File fooWar = new File(x, "foo.war");
-        IO.copy(new File(srcDir, "foo-webapp-1.war"), fooWar);
+        IO.copy(srcDir.resolve("foo-webapp-1.war").toFile(), fooWar);
         assertTrue(Files.exists(fooWar.toPath()));
 
-        //make a link from x to webapps
-        Files.createSymbolicLink(jetty.getJettyDir("webapps").toPath(), x.toPath());
-        assertTrue(Files.exists(jetty.getJettyDir("webapps").toPath()));
+        try
+        {
+            //make a link from x to webapps
+            Files.createSymbolicLink(jetty.getJettyDir("webapps").toPath(), x.toPath());
+            assertTrue(Files.exists(jetty.getJettyDir("webapps").toPath()));
+            symlinkSupported = true;
+        }
+        catch (UnsupportedOperationException | FileSystemException e)
+        {
+            // if unable to create symlink, no point testing that feature
+            // this is the path that Microsoft Windows takes.
+            symlinkSupported = false;
+        }
+        assumeTrue(symlinkSupported);
 
         jetty.load();
         jetty.start();
@@ -179,10 +188,6 @@ public void testWebappSymlinkDir() throws Exception
     @EnabledOnOs({LINUX})
     public void testBaseDirSymlink() throws Exception
     {
-        jetty.stop(); //reconfigure jetty
-
-        testdir.ensureEmpty();
-
         Path realBase = testdir.getEmptyPathDir();
 
         //set jetty up on the real base 
@@ -202,8 +207,8 @@ public void testBaseDirSymlink() throws Exception
         jetty.stop();
 
         //Make a symbolic link to the real base
-        File testsDir = MavenTestingUtils.getTargetTestingDir();
-        Path symlinkBase = Files.createSymbolicLink(testsDir.toPath().resolve("basedirsymlink-" + System.currentTimeMillis()), jettyHome);
+        Path testsDir = MavenTestingUtils.getTargetTestingPath();
+        Files.createSymbolicLink(testsDir.resolve("basedirsymlink-" + System.currentTimeMillis()), jettyHome);
         Map<String, String> properties = new HashMap<>();
         properties.put("jetty.home", jettyHome.toString());
         //Start jetty, but this time running from the symlinked base 
@@ -215,7 +220,6 @@ public void testBaseDirSymlink() throws Exception
         try
         {
             server.start();
-            HandlerCollection handlers = (HandlerCollection)server.getHandler();
             Handler[] children = server.getChildHandlersByClass(WebAppContext.class);
             assertEquals(1, children.length);
             assertEquals("/foo", ((WebAppContext)children[0]).getContextPath());
@@ -225,12 +229,62 @@ public void testBaseDirSymlink() throws Exception
             server.stop();
         }
     }
-
-    private Map<String, String> setupJettyProperties(Path jettyHome)
+
+    @Test
+    public void testDelayedDeploy() throws Exception
     {
+        Path realBase = testdir.getEmptyPathDir();
+
+        //set jetty up on the real base
+        jetty = new XmlConfiguredJetty(realBase);
+        jetty.addConfiguration("jetty.xml");
+        jetty.addConfiguration("jetty-http.xml");
+        jetty.addConfiguration("jetty-deploy-wars.xml");
+
+        //Put a webapp into the base
+        jetty.copyWebapp("foo-webapp-1.war", "foo.war");
+
+        Path jettyHome = jetty.getJettyHome().toPath();
+
         Map<String, String> properties = new HashMap<>();
-        properties.put("jetty.home", jettyHome.toFile().getAbsolutePath());
-        return properties;
+        properties.put("jetty.home", jettyHome.toString());
+        properties.put("jetty.deploy.deferInitialScan", "true");
+        //Start jetty, but this time running from the symlinked base
+        System.setProperty("jetty.home", properties.get("jetty.home"));
+
+        List<Resource> configurations = jetty.getConfigurations();
+        Server server = XmlConfiguredJetty.loadConfigurations(configurations, properties);
+
+        try
+        {
+            server.start();
+
+            DeploymentManager deploymentManager = server.getBean(DeploymentManager.class);
+            for (AppProvider appProvider : deploymentManager.getAppProviders())
+            {
+                if (appProvider instanceof ScanningAppProvider)
+                {
+                    ScanningAppProvider scanningAppProvider = (ScanningAppProvider)appProvider;
+                    assertTrue(scanningAppProvider.isDeferInitialScan(), "The DeferInitialScan configuration should be true");
+                }
+            }
+
+            // Wait till the webapp is deployed and started
+            await().atMost(Duration.ofSeconds(5)).until(() ->
+            {
+                Handler[] children = server.getChildHandlersByClass(WebAppContext.class);
+                if (children == null || children.length == 0)
+                    return false;
+                WebAppContext webAppContext = (WebAppContext)children[0];
+                if (webAppContext.isStarted())
+                    return webAppContext.getContextPath();
+                return null;
+            }, is("/foo"));
+        }
+        finally
+        {
+            server.stop();
+        }
     }
 
     private static boolean hasJettyGeneratedPath(File basedir, String expectedWarFilename)