4. 外掛程式

4.1. Installation

To install the HelloWorld example plugin for testing the servers, you firstly have to create a directory to hold server plugins. This will be specified in the virtual host configuration and passed on to the server through an environment variable:

mkdir -p /var/www/qgis-server/plugins
cd /var/www/qgis-server/plugins
wget https://github.com/elpaso/qgis-helloserver/archive/master.zip
unzip master.zip
mv qgis-helloserver-master HelloServer

4.2. HTTP Server configuration

4.2.1. Apache

To be able to use server plugins, FastCGI needs to know where to look. So, we have to modify the Apache configuration file to indicate the QGIS_PLUGINPATH environment variable to FastCGI:

FcgidInitialEnv QGIS_PLUGINPATH "/var/www/qgis-server/plugins"

Moreover, a basic HTTP authorization is necessary to play with the HelloWorld plugin previously introduced. So we have to update the Apache configuration file a last time:

# Needed for QGIS HelloServer plugin HTTP BASIC auth
<IfModule mod_fcgid.c>
    RewriteEngine on
    RewriteCond %{HTTP:Authorization} .
    RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
</IfModule>

Then, restart Apache:

systemctl restart apache2

4.3. How to use a plugin

Test the server with the HelloWorld plugin:

wget -q -O - "http://localhost/cgi-bin/qgis_mapserv.fcgi?SERVICE=HELLO"
 HelloServer!

You can have a look at the default GetCapabilities of the QGIS server at:

http://localhost/cgi-bin/qgis_mapserv.fcgi?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities