This plugin adds a new request to QGIS Server getprintatlas which allows to export a print composer with an atlas configured, but passing an expression parameter to choose which feature is the current atlas feature.
We assume you have a fully functionnal QGIS Server. See https://docs.qgis.org/2.18/en/docs/user_manual/working_with_ogc/server/index.html
We need to download the plugin, and tell QGIS Server where the plugins are stored, the reload the web server. For example on Debian:
# Create needed directory to store plugins
mkdir -p /srv/qgis/plugins
# Get last version
cd /srv/qgis/plugins
wget "https://github.com/3liz/qgis-atlasprint/archive/master.zip"
unzip master.zip
mv qgis-atlasprint-master atlastprint
# Make sure correct environment variables are set in your web server configuration
# for example in Apache2 with mod_fcgid
nano /etc/apache2/mods-available/fcgid.conf
FcgidInitialEnv QGIS_PLUGINPATH "/srv/qgis/plugins/"
# Reload server, for example with Apache2
service apache2 reload
You can now test your installation