Plugins

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:

sudo mkdir -p /opt/qgis-server/plugins
cd /opt/qgis-server/plugins
sudo wget https://github.com/elpaso/qgis-helloserver/archive/master.zip
In case unzip was not installed before:
sudo apt install unzip
sudo unzip master.zip
sudo mv qgis-helloserver-master HelloServer

HTTP Server configuration

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_SERVER_LOG_FILE /tmp/qgis-000.log
FcgidInitialEnv QGIS_SERVER_LOG_LEVEL 0
FcgidInitialEnv QGIS_PLUGINPATH "/opt/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:

sudo a2ensite 001-qgis-server
sudo service apache2 restart

小技巧

If you work with a feature that has many nodes then modifying and adding a new feature will fail. In this case it is possible to insert the following code into the 001-qgis-server.conf file:

<IfModule mod_fcgid.c>
FcgidMaxRequestLen 26214400
FcgidConnectTimeout 60
</IfModule>

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