Make the path that jenkins is accessible on configureable

README.adoc

@@ -163,6 +163,7 @@ Advanced arguments:
   This option is considered safe for the Vanilla package with the default plugin set.
 * `--httpPort` - Port for exposing the web server and Jenkins Web UI from Jenkinsfile Runner.
   Disabled by default.
+* `--httpPath` - The root path/prefix for expositng the web server and Jenkins Web UI from Jenkinsfile Runner.
 * `--agentPort` - Port for connecting inbound Jenkins agents (over JNLP or WebSockets).
   Disabled by default.
 

bootstrap/src/main/java/io/jenkins/jenkinsfile/runner/bootstrap/commands/JenkinsLauncherOptions.java

@@ -68,6 +68,11 @@ public class JenkinsLauncherOptions {
             description = "Port for exposing the web server and Jenkins Web UI from Jenkinsfile Runner. Disabled by default")
     public Integer httpPort;
 
+    @CheckForNull
+    @CommandLine.Option(names = "--httpPath",
+                        description = "Path (including leading / but no trailing /) for exposing the web server and Jenkins Web UI from Jenkinsfile Runner. Root path (/) by default")
+    public String httpPath;
+
     @CheckForNull
     @CommandLine.Option(names = "--agentPort",
             description = "Port for connecting inbound Jenkins agents (over JNLP or WebSockets). Disabled by default")

setup/src/main/java/io/jenkins/jenkinsfile/runner/JenkinsEmbedder.java

@@ -86,6 +86,7 @@
 import jenkins.model.Jenkins;
 import jenkins.model.JenkinsLocationConfiguration;
 import org.apache.commons.io.FileUtils;
+import org.apache.commons.lang.StringUtils;
 import org.eclipse.jetty.http.MimeTypes;
 import org.eclipse.jetty.security.LoginService;
 import org.eclipse.jetty.server.Server;
@@ -119,6 +120,14 @@ public abstract class JenkinsEmbedder implements RootAction {
     protected int localPort;
     protected Server server;
 
+    /**
+     * Where in the {@link Server} is Jenkins deployed?
+     * <p>
+     * Just like {@link javax.servlet.ServletContext#getContextPath()}, starts with '/' but doesn't end with '/'.
+     */
+    @CheckForNull
+    protected String contextPath;
+
     /**
      * {@link Runnable}s to be invoked at {@link #after()} .
      */
@@ -383,7 +392,7 @@ public Launcher.LocalLauncher createLocalLauncher() {
      * URL ends with '/'.
      */
     public URL getURL() throws IOException {
-        return new URL("http://localhost:" + localPort + "/");
+        return new URL("http://localhost:" + localPort + StringUtils.defaultString(contextPath) + "/");
     }
 
     /**

setup/src/main/java/io/jenkins/jenkinsfile/runner/JenkinsLauncher.java

@@ -17,6 +17,7 @@
 import jenkins.model.Jenkins;
 import jenkins.util.SystemProperties;
 import org.apache.commons.io.FileUtils;
+import org.apache.commons.lang.StringUtils;
 import org.eclipse.jetty.security.AbstractLoginService;
 import org.eclipse.jetty.security.LoginService;
 import org.eclipse.jetty.server.Server;
@@ -77,7 +78,8 @@ protected ServletContext createWebServer() throws Exception {
                 ? new Server(launcherOptions.httpPort)
                 : new Server(queuedThreadPool);
 
-        WebAppContext context = new WebAppContext(launcherOptions.warDir.getPath(), null);
+        contextPath = validateHttpPath(launcherOptions.httpPath);
+        WebAppContext context = new WebAppContext(launcherOptions.warDir.getPath(), contextPath);
         context.setClassLoader(getClass().getClassLoader());
         context.setConfigurations(new Configuration[]{new WebXmlConfiguration()});
         context.addBean(new NoListenerConfiguration(context));
@@ -107,6 +109,15 @@ protected ServletContext createWebServer() throws Exception {
         return context.getServletContext();
     }
 
+    private String validateHttpPath(String httpPath) throws IllegalArgumentException {
+        if (StringUtils.endsWith(httpPath, "/")) {
+            throw new IllegalArgumentException("httpPath must not end with a trailing /");
+        } else if ("".equals(httpPath)) {
+            throw new IllegalArgumentException("httpPath must not be empty. Omit this parameter to use the root path");
+        }
+        return httpPath;
+    }
+
     //TODO: add support of timeout
     /**
      * Launches the Jenkins instance, without any time out or output message.