LifeRequest

1. User types http://localhost:8080.
2. Browser sends HTTP GET http://localhost:8080.
3. Tomcat receives the request.
4. Resolves the application (ROOT).
5. R - Dispatches a request to Liferay.
6. Calls the Invoker Filter REQUEST.
7. Calls the VirtualHost filter that figures out the Group (Site).
8. R - Generates a new request to the site's friendly URL (/web/guest) that follows the same path.
9. This new request is handled by the Friendly URL Servlet:

   <servlet-mapping>
     <servlet-name>Friendly URL Servlet - Public</servlet-name>
     <url-pattern>/web/*</url-pattern>    
   </servlet-mapping>

   web.xml#L330-L333
10. R - It redirects to the main layout and triggers another request: /c/portal/layout?p_l_id=4&p_v_l_s_g_id=0.
11. This new request is handled by the Main Servlet:

    <servlet-mapping>
      <servlet-name>Main Servlet</servlet-name>
      <url-pattern>/c/*</url-pattern>    
    </servlet-mapping>

    web.xml#L302-L305
12. And it is delegated to the PortalRequestProcessor MainServlet.java#L204.
13. The request is mapped to a LayoutAction PortalRequestProcessor.java#L414.
14. The action calls layout.includeLayoutContent LayoutAction.java#L413.
15. The layout is a content layout therefore the ContentLayoutTypeController handles the rendering modules/apps/layout/layout-type-controller/layout-type-controller-content/src/main/resources/META-INF/resources/layout/edit_layout/content.jsp.
16. The rendered result is stored in request[LAYOUT_CONTENT] ContentLayoutTypeController.java#L207.
17. The request is forwarded to portal-web/docroot/html/common/themes/portal.jsp.
18. This jsp uses the theme taglib that retrieves the theme and calls the portal_normal.jsp template.
19. This ends up being rendered by the theme's portal_normal.ftl.
20. That calls portal-web/docroot/html/portal/layout.jsp which renders our layout inside the portal (tilesContent).