I released a new Grails plugin today, app-info. This plugin exposes a lot of internal information for a Grails application. Most of the code for this plugin dates back a long time and was originally mostly JSPs that I would copy into whatever application I was working on to give myself a view into what's going on. Over time as I started using Spring and Hibernate I added more pages to display that information, and it now also shows information about Grails too.

Click any of the images to see the full-size version in a new window.

Configuration

This plugin uses the Dynamic Controller plugin to modularize the controller actions as mixins. There are several of them and if there are some you don't want or need, you can exclude them. None are configured by default - that has to be done in your application's grails-app/conf/Config.groovy file. Here's the configuration from the sample application (download link at the end):

With this configuration all of the URLs will start with http://localhost:8080/appname/adminManage. My preference is to re-map these in grails-app/conf/UrlMappings.groovy to http://localhost:8080/appname/admin/manage since I want the administration parts of the application under /admin/**. This is optional but if you want to do this see the configuration in the sample app.

Note: This plugin exposes a lot of information about your application so you're strongly recommended to use a security plugin and guard these URLs. The sample application uses the Spring Security Core plugin but you're free to restrict access however you like, and optionally not even include this in your production war.

Usage

The Attributes menu has three entries:

Application

Displays all application-scope attributes from the ServletContext

Request

Displays all request-scope attributes from the current HttpServletRequest. Since this is for the current request, it's mostly useful to see what's available in a typical request.

Session

Displays all session-scope attributes from the current HttpSession. Since this is for the current request, it's mostly useful to see what's available in a typical session.

The Properties menu has three entries:

Data Source

A read/write view of the DataSource bean. Depending on the DataSource implementation, changing an attribute will take effect immediately and reset the connection pool

Grails Properties

Read-only view of the Grails Configuration.

System Properties

Read/write view of system properties. You can alter current properties or add new ones.

The Info menu has five entries:

Controllers

All controllers, plus links to all actions

Logging

Has comboboxes for all loggers to change the log level at runtime. Also has a text field to register a new Logger and its level.

Also includes a reverse-engineered log4j.xml based on the in-memory Log4j configuration. This is an estimate, so it may not be 100% accurate. But if you're having logging configuration issues and are familiar with the log4j.xml format, this can be convenient for diagnosing how things are misconfigured.

Memory

Graphs describing memory usage. Also has an action to trigger explicit garbage collection.

Sessions

Displays all current sessions and session-scope variables with a link to invalidate the session. This is enabled by default; to disable set grails.plugins.appinfo.useContextListener = false in grails-app/conf/Config.groovy