Py-QGIS-Server

Py-QGIS-Server has been designed to manage QGIS Server map processes.

Pre-requirements

We supposed, you already have installed QGIS Server packages, as explain in the QGIS Server documentation.

Poznámka

You do not need to read the web server configuration about Nginx/Apache in the documentation from QGIS. Because Py-QGIS-Server has its own web server.

Install in a Python venv

We add needed packages not provided with QGIS Server :

apt install python3-venv python3-psutil

Then, we create the Py-QGIS-Server virtual environment and install py-qgis-server with pip :

set -e
python3 -m venv /opt/local/py-qgis-server --system-site-packages
/opt/local/py-qgis-server/bin/pip install -U pip setuptools wheel pysocks typing py-qgis-server

Py-QGIS-Server is installed.

Configuration and associated files

Folders used below

mkdir -p /srv/qgis/plugins /srv/qgis/config /var/log/qgis /var/lib/py-qgis-server /var/data

The file to watch for restarting workers

We create an empty file that will be watch by Py-QGIS-Server to check when to restart QGIS Server map workers.

touch /var/lib/py-qgis-server/py-qgis-restartmon
chmod 664 /var/lib/py-qgis-server/py-qgis-restartmon

The bash file to restart workers

We create the executable file /usr/bin/qgis-reload to restart QGIS Server map workers. It will contain:

#!/bin/bash

touch /var/lib/py-qgis-server/py-qgis-restartmon

Then we when change its mod :

chmod 750 /usr/bin/qgis-reload

The configuration file

We create the Py-QGIS-Server configuration file /srv/qgis/server.conf. It will contain:

#
# Py-QGIS-Server configuration
# https://docs.3liz.org/py-qgis-server/
#

[server]
port = 7200
interfaces = 127.0.0.1
workers = 4
pluginpath = /srv/qgis/plugins
timeout = 200
restartmon = /var/lib/py-qgis-server/py-qgis-restartmon

[logging]
level = info

[projects.cache]
strict_check = false
rootdir = /srv/data
size = 50
advanced_report = no

[monitor:amqp]
routing_key =
default_routing_key=
host =

[api.endpoints]
lizmap_api=/lizmap

[api.enabled]
lizmap_api=yes

In this example:

QGIS Server will be available at http://127.0.0.1:7200/ows/
the plugins are installed in :file`/srv/qgis/plugins` (pluginpath). See Zásuvné moduly QGIS Server.
the file to watch for restarting workers is /var/lib/py-qgis-server/py-qgis-restartmon (restartmon).
the directory containing the projects to be published /srv/data (rootdir). The projects must be in sub-folders.
Lizmap QGIS Server API is enabled

Manage it with systemd

First of all, we create an environment file /srv/qgis/config/qgis-service.env with

LC_ALL=en_US.UTF-8
LANG=en_US.UTF-8
DISPLAY=:99
QGIS_OPTIONS_PATH=/srv/qgis/
QGIS_AUTH_DB_DIR_PATH=/srv/qgis/
GDAL_CACHEMAX=2048
QGIS_SERVER_CACHE_SIZE=2048
QGIS_SERVER_LIZMAP_REVEAL_SETTINGS=TRUE
QGIS_SERVER_FORCE_READONLY_LAYERS=TRUE
QGIS_SERVER_TRUST_LAYER_METADATA=TRUE
QGIS_SERVER_APPLICATION_NAME=qgis-server

In this file, we defined:

The lang
The Xvfb display port, needed to print PDF
The QGIS options and authDB path (needed for HTTPS, when used in remote layers such as OSM tiles)
Lizmap environment variable to reveal settings
Other QGIS Server variables, from the documentation.

Then we can create the QGIS service systemd file /etc/systemd/system/qgis.service with

[Unit]
Description=QGIS server
After=network.target

[Service]
Type=simple

ExecStart=/opt/local/py-qgis-server/bin/qgisserver -c /srv/qgis/server.conf

# FIXME it is recommended to have a script *synchronous*, which is not the case here
ExecReload=/usr/bin/qgis-reload

KillMode=control-group
KillSignal=SIGTERM
TimeoutStopSec=10

Restart=always

StandardOutput=append:/var/log/qgis/qgis-server.log
StandardError=inherit
SyslogIdentifier=qgis

EnvironmentFile=/srv/qgis/config/qgis-service.env
User=root

LimitNOFILE=4096

[Install]
WantedBy=multi-user.target

Finally, we enable the QGIS Server service to start it and to be sure it is started at system launch :

systemctl enable qgis
service qgis start

Debug and check

Tip

1. We can check that QGIS Server with Py-QGIS-Server is working with : curl http://127.0.0.1:7200/ows/

2. After the installation of Lizmap Server QGIS plugin, we can check with : curl http://127.0.0.1:7200/lizmap/server.json | jq '.' Read Zásuvné moduly QGIS Server with the use of QGIS-Plugin-Manager.

Adapt the Lizmap Web Client configuration

Either by editing manually the file lizmap/var/config/lizmapConfig.ini.php or by changing in Lizmap Web Client GUI :

[services]
;URL to QGIS Server for OGC web services
wmsServerURL="http://127.0.0.1:7200/ows/"
;URL to the API exposed by the Lizmap plugin for QGIS Server
lizmapPluginAPIURL="http://127.0.0.1:7200/lizmap/"

; path to find repositories
rootRepositories="/var/data"

Your Server information panel must show you the QGIS Server version and installed plugins.