QGIS 3 server via Docker

General information

The Docker image is built using Ubuntu 20.04 (Focal) and official QGIS DEBs from https://qgis.org/. It includes Nginx and Xvfb and can be used as a standalone service (via HTTP TCP port 80) or as FCGI backend (via TCP port 9993).

Requisites

You need Docker >= 18.04 with seccomp. Support for the statx syscall, required by Qt 5.10+, may be made necessary in the future. This is generally included in libseccomp >= 2.3.3; a kernel with statx support is also required; any kernel newer than 4.11 should be ok. Please check with your vendor.

Known good configurations are:

• Ubuntu 18.04.2+
• CentOS 8
• Fedora 29+

See https://github.com/gem/oq-qgis-server/issues/1 for further details.

Containers are not tested on hosts running OSes other than Linux.

Services provided

This Docker container exposes HTTP on port 80 via Nginx and a direct FastCGI on port 9993 that can be used directly by an external HTTP proxy (like the provided docker-compose.yml does). A sample Nginx configuration for using it as a FastCGI backend is also provided.

Available tags

Image name: openquake/qgis-server

QGIS stable

• stable | stable-ubuntu

QGIS LTR

• ltr | ltr-ubuntu

Example:

$ docker pull openquake/qgis-server:ltr

Build the container

QGIS stable

$ docker build -t openquake/qgis-server:stable .

QGIS LTR

$ docker build --build-arg repo=ubuntu-ltr -t openquake/qgis-server:ltr .

You may skip this step. The container will be downloaded from the Docker Hub.

Run the docker and map host data

$ docker run -v $(pwd)/data:/io/data --name qgis-server -d -p 8010:80 openquake/qgis-server:ltr

WMS and WFS for a specific project will be published at http://localhost:8010/ogc/<project_name>. An /ows/ endpoint is also available for direct access to the fcgi (bypassing the map=<project_name> rewrite). Direct access to WFS3 is accessible via http://localhost:8010/wfs3/.

PostgreSQL connection service file (optional)

The connection service file allows connection parameters to be associated with a single service name and thus to be able to use the same QGIS projects in different environments. This could also be achieved with QGIS authentications. To use a pg_service file you need to bind mount it as shown in the docker-compose or on run:

-v $(pwd)/conf/pg_service.conf:/etc/postgresql-common/pg_service.conf:ro

Plugins, fonts and SVG symbols (optional)

Plugins, custom fonts and SVG can be optionally exposed from host to the containers:

Plugins

-v $(pwd)/plugins:/io/plugins

Fonts

-v $(pwd)/fonts:/usr/share/fonts

SVG symbols

-v $(pwd)/svg:/var/lib/qgis/.local/share/QGIS/QGIS3/profiles/default/svg

Example:

$ docker run -v $(pwd)/data:/io/data -v $(pwd)/plugins:/io/plugins -v $(pwd)/fonts:/usr/share/fonts --name qgis-server -d -p 8010:80 openquake/qgis-server:ltr

Access the container via bash

$ docker exec -ti qgis-server /bin/bash

where qgis-server is the name of the container.

Logs and debugging

QGIS server log can retreived via docker logs

$ docker logs [-f] qgis-server

where qgis-server is the name of the container.

Default log level is set to warning. Log level can be increased during container deployment passing the -e QGIS_SERVER_LOG_LEVEL=0 option:

$ docker run -e QGIS_SERVER_LOG_LEVEL=0 -v $(pwd)/data:/io/data -v $(pwd)/plugins:/io/plugins --name qgis-server -d -p 8010:80 openquake/qgis-server:ltr

Run the docker and map host data (via docker-compose)

Adjust first the configuration in conf/nginx.conf with the proper number of expected workers and docker-compose.yml with the path of data folder on the host.

Then:

$ docker-compose up -d --scale qgis-server=N

Where N is the number of expected QGIS server workers.

Data dir structure

$(pwd)/data must have the following structure:

data 
 |
 |-- <project_name>
      |-- <project_name>.qgs

oq-consolidate may helps you in exporting data suitable for QGIS server (consolidating project and layers).

$(pwd)/plugins must have the following structure:

plugins
 |
 |-- <plugin_name>
      |-- <plugin_code>.py
      |-- metadata.txt
      |-- __init__.py

Custom fonts are loaded into /usr/share/fonts. fc-cache is run when container is started.

Runtime customizations

The following variables can be customized during container deployment:

Nginx

When SKIP_NGINX is set to a different value than 0 or false the embedded copy of Nginx will not be started and an external reverse proxy is then required to access the FastCGI QGIS backend.

• SKIP_NGINX: default is unset (do not skip Nginx startup)

QGIS

• QGIS_SERVER_LOG_LEVEL: default is 1
• QGIS_SERVER_PARALLEL_RENDERING: default is true
• QGIS_SERVER_MAX_THREADS: default is 2
• QGIS_SERVER_WMS_MAX_WIDTH: not set by default
• QGIS_SERVER_WMS_MAX_WIDTH: not set by default

See QGIS server documentation for further details.

It is also possible to customized the ID of the user running QGIS server processes when it is required to write to host volumes (see notes):

• QGIS_USER: default is nginx, a numerical id must be proivided

Example: docker run -e QGIS_USER=1000 or docker run -e QGIS_USER=$(id -u qgis)

Notes

GeoPackages do not play well with multiple processes having gpkg files opened in rw mode. By default QGIS server processes lack write permission on /io/data. If it is required to let QGIS server write data to /io/data make sure that either you are using a process-safe datastore (i.e. a Postgres backend) or you are limiting horizontal scaling to one container only. QGIS server user can be customized via the QGIS_USER environment variable.