GSIP 143

GSIP 143 - Extension Status

Overview

Plugins should be able to easily report basic status information: the status page would benefit from this information, and the same information could be reported via rest api.

Proposed By

• Morgan Thompson
• Kevin Smith
• Jody Garnett

Assigned to Release

This is for GeoServer 2.10. (or 2.9 if available)

State

• Under Discussion
• In Progress
• Completed
• Rejected
• Deferred

Motivation

It's tricky/tedious to tell which extensions are configured/installed. As per GEOS-6068 we would like an extension point to report configuration and installation details.

Proposal

Proposed ExtensionStatus interface:

interface ExtensionStatus {
   String getName();
   String getVersion();
   boolean isAvailable();
   boolean isEnabled();

   /** Optional status message */
   String getMessage();

   /** Relative documentation link link to user manual */
   String getDocumentation();

   // as requested by kevin
   boolean canUserEnable();
   boolean getUserEnabled();
   void setUserEnabled( boolean enabled );
}

Kevin has requested canUserDisable(), getUserEnabled() and setUserEnabled(boolean) to control services such as WFS, WFS and WCS in a single location.

marlin extension

Environment based extensions can be reported by gs-main, which would register several ExtensionStatus beans in applicationContext.xml:

<bean id="extensionStatus" class="org.geoserver.web.ExtensionStatus">
  <property name="id" value="server.admin.extensionStatus" />
  <property name="nameKey" value="ExtensionStatus.name" />
  <property name="componenetClass" value="org.geoserver.web.admin.ExtensionStatusPage" />
</bean>

Here is an example of reporting Java Rasterizer:

  private String checkRenderer() {
        try {
            String renderer = sun.java2d.pipe.RenderingEngine.getInstance().getClass().getName();
            return renderer;
        } catch(Throwable e) {
            return "Unknown";
        }
    }

This can also be used to report webapp.xml settings such as speed strategy.

libjpegturbo extension

An extension such as libjpegturbo that requires native libraries would use:

Main would register several ExtensionStatus beans in applicationContext.xml:

<extension>
</extension>

gs-oracle extension

Many extensions, such as gs-oracle, just provide a maven dependency. To make use of ExtensionStatus an applicationContext.xml would be added configuring a prebuild DataStoreExtension bean.

<extension>
</extension>

The DataStoreExtension bean references the GeoTools DataStoreFactorySPI (to check the isAvaialble) method, and lists several additional classes to check using Class.forName (to verify oracle driver is available).

Status Page

Open to suggestions, recommend adding an "extensions" tab to the existing status page, with extensions listed on the right alphabetically and a table on the right showing the details.

REST API

Similar to about/manifest we propose an about/extension.xml (or json) endpoint:

<about>
   <extension>
     <name>gs-main/rasterizer</name>
     <version>0.7.3</version>
     <enabled>true</enabled>
     <status>available</status>
     <message>
         Java 2D configured with org.marlin.pisces.PicesRenderingEngine.
         System property: -Dsun.java2d.renderer=org.marlin.pisces.PiscesRenderingEngine.
         Boot classpath contains marlin-0.7.3.jar
     </message>
   </extension>
   <extension>
     <name>gs-libjpeg-turbo</name>
     <version>2.9.0</version>
     <status>available</status>
     <enabled>true</enabled>
     <message>
         Using lib-jepg-turbo 1.4.2.
         System property -Ddisable.turbojpeg=(unset)
     <message>
     <documentation>
         http://docs.geoserver.org/latest/en/user/extensions/libjpeg-turbo/index.html
     </documentation>
   </extension>
   <extension>
     <name>gs-oracle</name>
     <version>2.9.0</version>
     <status>unavailable</status>
     <enabled>true</enabled>
     <message>
         JDBC Driver not installed (add ojdbc7 to WEB-INF/lib directory).
     <message>
     <documentation>
        http://docs.geoserver.org/stable/en/user/data/database/oracle.html
     </documentation>
   </extension>
</about>

Backwards Compatibility

Feedback

Jody wonders if we should consider MBeans (or is that overkill).

Voting

Project Steering Committee:

• Alessio Fabiani:
• Andrea Aime:
• Ben Caradoc-Davies:
• Brad Hards:
• Christian Mueller:
• Ian Turton:
• Jody Garnett:
• Jukka Rahkonen:
• Kevin Smith:
• Simone Giannecchini:

Links

• [Bug Report] https://osgeo-org.atlassian.net/browse/GEOS-6068
• [Email Discussion]