Configuration and ZOO-Kernel use

ZOO-Project Installation

To be able to follow the current material, you will have to download and uncompress an archive containing the dataset, ZOO-Kernel and required services. It was made available specifically for this workshop and is available at :

You should use the following commands to download then uncompress the archive and get it extracted with correct privileges:

sudo tar -xvjpf ws2013-1.tar.bz2 -C /
psql -f /var/www/temp/ws2013.sql pgrouting

ZOO-Kernel Configuration

As already said in introduction, an OSGeoLive has been booted on your computer, allowing you to use ZOO-Kernel in a development environment directly.


we will use ZOO-Kernel or zoo_loader.cgi script without any distinction in this document.

General ZOO-Kernel settings are set in the main.cfg file located in the same directory as the ZOO-Kernel, so in /usr/lib/cgi-bin/. You can see a typical main.cfg content in the following:

14title=The ZOO-Project WPS Server FOSS4G 2013 Nottingham Workshop
16abstract=ZOO-Project platform 2013 .See for more informations
24addressDeliveryPoint=1280 Av. des Platanes
33individualName=Gérald FENOY

The main.cfg file contains metadata informations about the identification and provider but also some important settings. The file is composed of various sections, namely [main], [identification] and [provider] per default.

From the [main] section settings are as follow:
  • lang: the supported languages separated by a coma (the first is the default one),

  • version: the supported WPS version,

  • encoding: the default encoding of WPS Responses,

  • serverAddress: the url to access your ZOO-Kernel instance,

  • dataPath: the path to store data files (when MapServer support was activated, this directory is used to store mapfiles and data).

  • tmpPath: the path to store temporary files (such as ExecuteResponse when storeExecuteResponse was set to true),

  • tmpUrl: a url relative to serverAddress to access the temporary file,

  • cacheDir: the path to store cached request files [1] (optional),

  • mapservAddress: your local MapServer address (optional),

  • msOgcVersion: the version for all supported OGC Web Services output [2] (optional).

The [identification] and [provider] section are specific to OGC metadata and should be set [3].

Obviously, you are free to add new sections to this file if you need more. Nevertheless, you have to know that there is some specific names you should use only for specific needs: [headers], [mapserver], [env], [lenv] and [senv].


[senv] and [lenv] are used / produced on runtime internaly by the ZOO-Kernel and should be defined only from the Service code.

The headers section is used to define your own HTTP Response headers. You may take a look at headers returned by web site such as by using curl command line tool for instance and notice the specific heder X-Powered-By: Zoo-Project@Trac.


There is no reason to define basic headers such as Content-Type or encoding as they will be overwritten at runtime by the ZOO-Kernel.

The mapserver section is used to store specific mapserver configuration parameter such as PROJ_LIB and GDAL_DATA or any other you want to be set to make your MapServer working.


the mapserver section is mainly used on WIN32 platform

The env section is used to store specific environment variables you want to be set prior to load your Services Provider and run your Service. A typical example, is when your Service requires to access to a X server running on framebuffer, then you will have to set the DISPLAY environnement variable, in this case you would add DISPLAY=:1 line in your [env] section.

The lenv is used to store runtime informations automatically set by the ZOO-Kernel before running your service and can be accesses / updated from it:

  • sid: the service unique identifier,

  • status: the current progress value (value between 0 and 100, percent),

  • cwd: the current working directory of the ZOO-Kernel,

  • message: an error message when returning SERVICE_FAILED (optional),

  • cookie: the cookie your service want to return to the client (for authentication purpose or tracking).

The senv is used to store session informations on the server side. You can then access them automatically from service if the server is requested using a valid cookie (as defined in lenv > cookie). The ZOO-Kernel will store on disk the values set in the senv maps, then load it and dynamically add its content to the one available in the main.cfg. The senv section should contain at least:

  • XXX: the session unique identifier where XXX is the name included in the

    returned cookie.

conf["lenv"]["cookie"]="XXX=XXX1000000; path=/"
conf["senv"]={"XXX": "XXX1000000","login": "demoUser"}

That means that the ZOO-Kernel will create a file sess_XXX1000000.cfg in the cacheDir and return the specified cookie to the client. Each time the client will request the ZOO-Kernel using the Cookie, it will automatically load the value stored before running your service. You can then easilly access this informations from your service source code. This functionality won’t be used in the following presentation.

Testing the ZOO installation with GetCapabilities

You can request ZOO-Kernel using the following link from your Internet browser:


You should get a valid Capabilities XML document, looking like the following :


Please note that some Process node are returned in the ProcessOfferings section, as somes are available already on OSGeoLive DVD. You can also run a GetCapabilities request from the command line, using the following command:

cd /usr/lib/cgi-bin
./zoo_loader.cgi “request=GetCapabilities&service=WPS”

The same result as in your browser will be returned, as shown in the following screenshot:


Invoking ZOO Kernel from command line can be helpful during development process of new Services.