2. Первые шаги

2.1. Installation on Debian-based systems

We will give a short and simple installation how-to for a minimal working configuration on Debian based systems (including Ubuntu and derivatives). However, many other distributions and OSs provide packages for QGIS Server.

Примечание

In Ubuntu you can use your regular user, prepending sudo to commands requiring admin permissions. In Debian you can work as admin (root), without using sudo.

Requirements and steps to add official QGIS repositories to install QGIS Server on a Debian based system are provided in QGIS installers page. You may want to install at least the latest Long Term Release.

Once the target version repository is configured and QGIS Server installed, you can test the installation with:

/usr/lib/cgi-bin/qgis_mapserv.fcgi

If you get the following output, the server is correctly installed.

Примечание

Depending on the version of QGIS, you might see slightly different output reported when you run qgis_mapserv.fcgi.

QFSFileEngine::open: No file name specified
Warning 1: Unable to find driver ECW to unload from GDAL_SKIP environment variable.
Warning 1: Unable to find driver ECW to unload from GDAL_SKIP environment variable.
Warning 1: Unable to find driver JP2ECW to unload from GDAL_SKIP environment variable.
Warning 1: Unable to find driver ECW to unload from GDAL_SKIP environment variable.
Warning 1: Unable to find driver JP2ECW to unload from GDAL_SKIP environment variable.
Content-Length: 206
Content-Type: text/xml; charset=utf-8

<ServiceExceptionReport version="1.3.0" xmlns="https://www.opengis.net/ogc">
 <ServiceException code="Service configuration error">Service unknown or unsupported</ServiceException>
</ServiceExceptionReport>

Примечание

As seen below, QGIS reports a Status 400 code, which correctly identifies the request has failed because there is no active http session. This is not a bug and indicates the server is functioning properly.

Application path not initialized
Application path not initialized
Warning 1: Unable to find driver ECW to unload from GDAL_SKIP environment variable.
Warning 1: Unable to find driver ECW to unload from GDAL_SKIP environment variable.
Warning 1: Unable to find driver JP2ECW to unload from GDAL_SKIP environment variable.
"Loading native module /usr/lib/qgis/server/libdummy.so"
"Loading native module /usr/lib/qgis/server/liblandingpage.so"
"Loading native module /usr/lib/qgis/server/libwcs.so"
"Loading native module /usr/lib/qgis/server/libwfs.so"
"Loading native module /usr/lib/qgis/server/libwfs3.so"
"Loading native module /usr/lib/qgis/server/libwms.so"
"Loading native module /usr/lib/qgis/server/libwmts.so"
QFSFileEngine::open: No file name specified
Content-Length: 102
Content-Type: application/json
Server:  QGIS FCGI server - QGIS version 3.16.6-Hannover
Status:  400
[{"code":"Bad request error","description":"Requested URI does not match any registered API handler"}]

Let’s add a sample project. You can use your own, or one from Training demo data:

mkdir /home/qgis/projects/
cd /home/qgis/projects/
wget https://github.com/qgis/QGIS-Training-Data/archive/release_3.16.zip
unzip release_3.16.zip
mv QGIS-Training-Data-release_3.16/exercise_data/qgis-server-tutorial-data/world.qgs .
mv QGIS-Training-Data-release_3.16/exercise_data/qgis-server-tutorial-data/naturalearth.sqlite .

Of course, you can use your favorite GIS software to open this file and take a look at the configuration and available layers.

To properly deploy QGIS server you need a HTTP server. Recommended choices are Apache or NGINX.

2.1.1. Apache HTTP Server

Примечание

In the following, please replace qgis.demo with the name or IP address of your server.

Install Apache and mod_fcgid:

apt install apache2 libapache2-mod-fcgid

You can run QGIS Server on your default website, or configure a virtualhost specifically for this, as follows.

In the /etc/apache2/sites-available directory let’s create a file called qgis.demo.conf, with this content:

<VirtualHost *:80>
  ServerAdmin webmaster@localhost
  ServerName qgis.demo

  DocumentRoot /var/www/html

  # Apache logs (different than QGIS Server log)
  ErrorLog ${APACHE_LOG_DIR}/qgis.demo.error.log
  CustomLog ${APACHE_LOG_DIR}/qgis.demo.access.log combined

  # Longer timeout for WPS... default = 40
  FcgidIOTimeout 120

  FcgidInitialEnv LC_ALL "en_US.UTF-8"
  FcgidInitialEnv PYTHONIOENCODING UTF-8
  FcgidInitialEnv LANG "en_US.UTF-8"

  # QGIS log
  FcgidInitialEnv QGIS_SERVER_LOG_STDERR 1
  FcgidInitialEnv QGIS_SERVER_LOG_LEVEL 0

  # default QGIS project
  SetEnv QGIS_PROJECT_FILE /home/qgis/projects/world.qgs

  # QGIS_AUTH_DB_DIR_PATH must lead to a directory writeable by the Server's FCGI process user
  FcgidInitialEnv QGIS_AUTH_DB_DIR_PATH "/home/qgis/qgisserverdb/"
  FcgidInitialEnv QGIS_AUTH_PASSWORD_FILE "/home/qgis/qgisserverdb/qgis-auth.db"

  # Set pg access via pg_service file
  SetEnv PGSERVICEFILE /home/qgis/.pg_service.conf
  FcgidInitialEnv PGPASSFILE "/home/qgis/.pgpass"

  # if qgis-server is installed from packages in debian based distros this is usually /usr/lib/cgi-bin/
  # run "locate qgis_mapserv.fcgi" if you don't know where qgis_mapserv.fcgi is
  ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
  <Directory "/usr/lib/cgi-bin/">
    AllowOverride None
    Options +ExecCGI -MultiViews -SymLinksIfOwnerMatch
    Order allow,deny
    Allow from all
    Require all granted
  </Directory>

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

</VirtualHost>

Further readings:

You can do the above in a linux Desktop system by pasting and saving the above configuration after doing:

nano /etc/apache2/sites-available/qgis.demo.conf

Примечание

Some of the configuration options are explained in the Server environment variables section.

Let’s now create the directories that will store the QGIS Server logs and the authentication database:

mkdir -p /var/log/qgis/
chown www-data:www-data /var/log/qgis
mkdir -p /home/qgis/qgisserverdb
chown www-data:www-data /home/qgis/qgisserverdb

Примечание

www-data is the Apache user on Debian based systems and we need Apache to have access to those locations or files. The chown www-data... commands change the owner of the respective directories and files to www-data.

We can now enable the virtual host, enable the fcgid mod if it’s not already enabled:

a2enmod fcgid
a2ensite qgis.demo

Now restart Apache for the new configuration to be taken into account:

systemctl restart apache2

Now that Apache knows that he should answer requests to http://qgis.demo we also need to setup the client system so that it knows who qgis.demo is. We do that by adding 127.0.0.1 qgis.demo in the hosts file. We can do it with sh -c "echo '127.0.0.1 qgis.demo' >> /etc/hosts". Replace 127.0.0.1 with the IP of your server.

Примечание

Remember that both the qgis.demo.conf and /etc/hosts files should be configured for your setup to work. You can also test the access to your QGIS Server from other clients on the network (e.g. Windows or macOS machines) by going to their /etc/hosts file and point the myhost name to whatever IP the server machine has on the network (not 127.0.0.1 as it is the local IP, only accessible from the local machine). On *nix machines the hosts file is located in /etc, while on Windows it’s under the C:\Windows\System32\drivers\etc directory. Under Windows you need to start your text editor with administrator privileges before opening the hosts file.

QGIS Server is now available at http://qgis.demo. To check, type in a browser, as in the simple case:

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

2.1.2. NGINX HTTP Server

Примечание

In the following, please replace qgis.demo with the name or IP address of your server.

You can also use QGIS Server with NGINX. Unlike Apache, NGINX does not automatically spawn FastCGI processes. The FastCGI processes are to be started by something else.

Install NGINX:

apt install nginx
  • As a first option, you can use spawn-fcgi or fcgiwrap to start and manage the QGIS Server processes. Official Debian packages exist for both. When you have no X server running and you need, for example, printing, you can use xvfb.

  • Another option is to rely on Systemd, the init system for GNU/Linux that most Linux distributions use today. One of the advantages of this method is that it requires no other components or processes. It’s meant to be simple, yet robust and efficient for production deployments.

NGINX Configuration

The include fastcgi_params; used in the previous configuration is important, as it adds the parameters from /etc/nginx/fastcgi_params:

fastcgi_param  QUERY_STRING       $query_string;
fastcgi_param  REQUEST_METHOD     $request_method;
fastcgi_param  CONTENT_TYPE       $content_type;
fastcgi_param  CONTENT_LENGTH     $content_length;

fastcgi_param  SCRIPT_NAME        $fastcgi_script_name;
fastcgi_param  REQUEST_URI        $request_uri;
fastcgi_param  DOCUMENT_URI       $document_uri;
fastcgi_param  DOCUMENT_ROOT      $document_root;
fastcgi_param  SERVER_PROTOCOL    $server_protocol;
fastcgi_param  REQUEST_SCHEME     $scheme;
fastcgi_param  HTTPS              $https if_not_empty;

fastcgi_param  GATEWAY_INTERFACE  CGI/1.1;
fastcgi_param  SERVER_SOFTWARE    nginx/$nginx_version;

fastcgi_param  REMOTE_ADDR        $remote_addr;
fastcgi_param  REMOTE_PORT        $remote_port;
fastcgi_param  SERVER_ADDR        $server_addr;
fastcgi_param  SERVER_PORT        $server_port;
fastcgi_param  SERVER_NAME        $server_name;

# PHP only, required if PHP was built with --enable-force-cgi-redirect
fastcgi_param  REDIRECT_STATUS    200;

Moreover, you can use some Переменные среды to configure QGIS Server. In the NGINX configuration file, /etc/nginx/nginx.conf, you have to use fastcgi_param instruction to define these variables as shown below:

location /qgisserver {
     gzip           off;
     include        fastcgi_params;
     fastcgi_param  QGIS_SERVER_LOG_STDERR  1;
     fastcgi_param  QGIS_SERVER_LOG_LEVEL   0;
     fastcgi_pass   unix:/var/run/qgisserver.socket;
 }

FastCGI wrappers

Предупреждение

fcgiwrap is easier to set up than spawn-fcgi, because it’s already wrapped in a Systemd service. But it also leads to a solution that is much slower than using spawn-fcgi. With fcgiwrap, a new QGIS Server process is created on each request, meaning that the QGIS Server initialization process, which includes reading and parsing the QGIS project file, is done on each request. With spawn-fcgi, the QGIS Server process remains alive between requests, resulting in much better performance. For that reason, spawn-fcgi is recommended for production use.

spawn-fcgi

If you want to use spawn-fcgi, the first step is to install the package:

apt install spawn-fcgi

Then, introduce the following block in your NGINX server configuration:

location /qgisserver {
    gzip           off;
    include        fastcgi_params;
    fastcgi_pass   unix:/var/run/qgisserver.socket;
}

And restart NGINX to take into account the new configuration:

systemctl restart nginx

Finally, considering that there is no default service file for spawn-fcgi, you have to manually start QGIS Server in your terminal:

spawn-fcgi -s /var/run/qgisserver.socket \
                -U www-data -G www-data -n \
                /usr/lib/cgi-bin/qgis_mapserv.fcgi

QGIS Server is now available at http://qgis.demo/qgisserver.

Примечание

When using spawn-fcgi, you may directly define environment variables before running the server. For example: export QGIS_SERVER_LOG_STDERR=1

Of course, you can add an init script to start QGIS Server at boot time or whenever you want. For example with systemd, edit the file /etc/systemd/system/qgis-server.service with this content:

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

[Service]
;; set env var as needed
;Environment="LANG=en_EN.UTF-8"
;Environment="QGIS_SERVER_PARALLEL_RENDERING=1"
;Environment="QGIS_SERVER_MAX_THREADS=12"
;Environment="QGIS_SERVER_LOG_LEVEL=0"
;Environment="QGIS_SERVER_LOG_STDERR=1"
;; or use a file:
;EnvironmentFile=/etc/qgis-server/env

ExecStart=spawn-fcgi -s /var/run/qgisserver.socket -U www-data -G www-data -n /usr/lib/cgi-bin/qgis_mapserv.fcgi

[Install]
WantedBy=multi-user.target

Then enable and start the service:

systemctl enable --now qgis-server

Предупреждение

With the above commands spawn-fcgi spawns only one QGIS Server process.

fcgiwrap

Using fcgiwrap is much easier to setup than spawn-fcgi but it’s much slower. You first have to install the corresponding package:

apt install fcgiwrap

Then, introduce the following block in your NGINX server configuration:

1
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  location /qgisserver {
      gzip           off;
      include        fastcgi_params;
      fastcgi_pass   unix:/var/run/fcgiwrap.socket;
      fastcgi_param  SCRIPT_FILENAME /usr/lib/cgi-bin/qgis_mapserv.fcgi;
  }

Finally, restart NGINX and fcgiwrap to take into account the new configuration:

systemctl restart nginx
systemctl restart fcgiwrap

QGIS Server is now available at http://qgis.demo/qgisserver.

Systemd

QGIS Server needs a running X Server to be fully usable, in particular for printing. In the case you already have a running X Server, you can use systemd services.

This method, to deploy QGIS Server, relies on two Systemd units:

The QGIS Server Socket unit defines and creates a file system socket, used by NGINX to start and communicate with QGIS Server. The Socket unit has to be configured with Accept=false, meaning that the calls to the accept() system call are delegated to the process created by the Service unit. It is located in /etc/systemd/system/qgis-server@.socket, which is actually a template:

[Unit]
Description=QGIS Server Listen Socket (instance %i)

[Socket]
Accept=false
ListenStream=/var/run/qgis-server-%i.sock
SocketUser=www-data
SocketGroup=www-data
SocketMode=0600

[Install]
WantedBy=sockets.target

Now enable and start sockets:

for i in 1 2 3 4; do systemctl enable --now qgis-server@$i.socket; done

The QGIS Server Service unit defines and starts the QGIS Server process. The important part is that the Service process’ standard input is connected to the socket defined by the Socket unit. This has to be configured using StandardInput=socket in the Service unit configuration located in /etc/systemd/system/qgis-server@.service:

[Unit]
Description=QGIS Server Service (instance %i)

[Service]
User=www-data
Group=www-data
StandardOutput=null
StandardError=journal
StandardInput=socket
ExecStart=/usr/lib/cgi-bin/qgis_mapserv.fcgi
EnvironmentFile=/etc/qgis-server/env

[Install]
WantedBy=multi-user.target

Примечание

The QGIS Server environment variables are defined in a separate file, /etc/qgis-server/env. It could look like this:

QGIS_PROJECT_FILE=/etc/qgis/myproject.qgs
QGIS_SERVER_LOG_STDERR=1
QGIS_SERVER_LOG_LEVEL=3

Now start socket service:

for i in 1 2 3 4; do systemctl enable --now qgis-server@$i.service; done

Finally, for the NGINX HTTP server, lets introduce the configuration for this setup:

upstream qgis-server_backend {
   server unix:/var/run/qgis-server-1.sock;
   server unix:/var/run/qgis-server-2.sock;
   server unix:/var/run/qgis-server-3.sock;
   server unix:/var/run/qgis-server-4.sock;
}

server {
   

   location /qgis-server {
       gzip off;
       include fastcgi_params;
       fastcgi_pass qgis-server_backend;
   }
}

Now restart NGINX for the new configuration to be taken into account:

systemctl restart nginx

Thanks to Oslandia for sharing their tutorial.

2.1.3. Xvfb

QGIS Server needs a running X Server to be fully usable, in particular for printing. On servers it is usually recommended not to install it, so you may use xvfb to have a virtual X environment.

If you’re running the Server in graphic/X11 environment then there is no need to install xvfb. More info at https://www.itopen.it/qgis-server-setup-notes/.

To install the package:

apt install xvfb

Create the service file, /etc/systemd/system/xvfb.service, with this content:

[Unit]
Description=X Virtual Frame Buffer Service
After=network.target

[Service]
ExecStart=/usr/bin/Xvfb :99 -screen 0 1024x768x24 -ac +extension GLX +render -noreset

[Install]
WantedBy=multi-user.target

Enable, start and check the status of the xvfb.service:

systemctl enable --now xvfb.service
systemctl status xvfb.service

Then, according to your HTTP server, you should configure the DISPLAY parameter or directly use xvfb-run.

With Apache

Then you can configure the DISPLAY parameter.

With Apache you just add to your FastCGI configuration (see above):

FcgidInitialEnv DISPLAY       ":99"

Now restart Apache for the new configuration to be taken into account:

systemctl restart apache2

With NGINX

Then you can directly use xvfb-run or configure the DISPLAY parameter.

  • With spawn-fcgi using xvfb-run:

    xvfb-run /usr/bin/spawn-fcgi -f /usr/lib/cgi-bin/qgis_mapserv.fcgi \
                                 -s /tmp/qgisserver.socket \
                                 -G www-data -U www-data -n
    
  • With the DISPLAY environment variable in the HTTP server configuration.

    fastcgi_param  DISPLAY       ":99";
    

2.2. Installation on Windows

QGIS Server can also be installed on Windows systems. While the QGIS Server package is available in the 64 bit version of the OSGeo4W network installer (https://qgis.org/en/site/forusers/download.html) there is no Apache (or other web server) package available, so this must be installed by other means.

A simple procedure is the following:

  1. Download the XAMPP installer (https://www.apachefriends.org/download.html) for Windows and install Apache

    ../../_images/qgis_server_windows1.png
  2. Download the OSGeo4W installer, follow the «Advanced Install» and install both the QGIS Desktop and QGIS Server packages

    ../../_images/qgis_server_windows2.png
  3. Edit the httpd.conf file (C:\xampp\apache\conf\httpd.conf if the default installation paths have been used) and make the following changes:

    From:

    ScriptAlias /cgi-bin/ "C:/xampp/cgi-bin/"
    

    To:

    ScriptAlias /cgi-bin/ "C:/OSGeo4W64/apps/qgis/bin/"
    

    From:

    <Directory "C:/xampp/cgi-bin">
        AllowOverride None
        Options None
        Require all granted
    </Directory>
    

    To:

    <Directory "C:/OSGeo4W64/apps/qgis/bin">
        SetHandler cgi-script
        AllowOverride None
        Options ExecCGI
        Order allow,deny
        Allow from all
        Require all granted
    </Directory>
    

    From:

    AddHandler cgi-script .cgi .pl .asp
    

    To:

    AddHandler cgi-script .cgi .pl .asp .exe
    
  4. Then at the bottom of httpd.conf add:

    SetEnv GDAL_DATA "C:\OSGeo4W64\share\gdal"
    SetEnv QGIS_AUTH_DB_DIR_PATH "C:\OSGeo4W64\apps\qgis\resources"
    SetEnv PYTHONHOME "C:\OSGeo4W64\apps\Python37"
    SetEnv PATH "C:\OSGeo4W64\bin;C:\OSGeo4W64\apps\qgis\bin;C:\OSGeo4W64\apps\Qt5\bin;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem"
    SetEnv QGIS_PREFIX_PATH "C:\OSGeo4W64\apps\qgis"
    SetEnv QT_PLUGIN_PATH "C:\OSGeo4W64\apps\qgis\qtplugins;C:\OSGeo4W64\apps\Qt5\plugins"
    
  5. Restart the Apache web server from the XAMPP Control Panel and open browser window to testing a GetCapabilities request to QGIS Server

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

2.3. Serve a project

Now that QGIS Server is installed and running, we just have to use it.

Obviously, we need a QGIS project to work on. Of course, you can fully customize your project by defining contact information, precise some restrictions on CRS or even exclude some layers. Everything you need to know about that is described later in Configure your project.

But for now, we are going to use a simple project already configured and previously downloaded in /home/qgis/projects/world.qgs, as described above.

By opening the project and taking a quick look on layers, we know that 4 layers are currently available:

  • airports

  • places

  • countries

  • countries_shapeburst

You don’t have to understand the full request for now but you may retrieve a map with some of the previous layers thanks to QGIS Server by doing something like this in your web browser to retrieve the countries layer:

http://qgis.demo/qgisserver?
  MAP=/home/qgis/projects/world.qgs&
  LAYERS=countries&
  SERVICE=WMS&
  VERSION=1.3.0&
  REQUEST=GetMap&
  CRS=EPSG:4326&
  WIDTH=400&
  HEIGHT=200&
  BBOX=-90,-180,90,180

If you obtain the next image, then QGIS Server is running correctly:

../../_images/server_basic_getmap.png

Рис. 2.1 Server response to a basic GetMap request

Note that you may define QGIS_PROJECT_FILE environment variable to use a project by default instead of giving a MAP parameter (see Переменные среды).

For example with spawn-fcgi:

export QGIS_PROJECT_FILE=/home/qgis/projects/world.qgs
spawn-fcgi -f /usr/lib/bin/cgi-bin/qgis_mapserv.fcgi \
           -s /var/run/qgisserver.socket \
           -U www-data -G www-data -n

2.4. Configure your project

To provide a new QGIS Server WMS, WFS or WCS, you have to create a QGIS project file with some data or use one of your current project. Define the colors and styles of the layers in QGIS and the project CRS, if not already defined.

../../_images/ows_server_definition.png

Рис. 2.2 Definitions for a QGIS Server WMS/WFS/WCS project

Then, go to the QGIS Server menu of the Project ► Properties… dialog and provide some information about the OWS in the fields under Service Capabilities. This will appear in the GetCapabilities response of the WMS, WFS or WCS. If you don’t check checkbox Service capabilities, QGIS Server will use the information given in the wms_metadata.xml file located in the cgi-bin folder.

2.4.1. WMS capabilities

In the WMS capabilities section, you can define the extent advertised in the WMS GetCapabilities response by entering the minimum and maximum X and Y values in the fields under Advertised extent. Clicking Use Current Canvas Extent sets these values to the extent currently displayed in the QGIS map canvas. By checking checkbox CRS restrictions, you can restrict in which coordinate reference systems (CRS) QGIS Server will offer to render maps. It is recommended that you restrict the offered CRS as this reduces the size of the WMS GetCapabilities response. Use the signPlus button below to select those CRSs from the Coordinate Reference System Selector, or click Used to add the CRSs used in the QGIS project to the list.

If you have print layouts defined in your project, they will be listed in the GetProjectSettings response, and they can be used by the GetPrint request to create prints, using one of the print layouts as a template. This is a QGIS-specific extension to the WMS 1.3.0 specification. If you want to exclude any print layout from being published by the WMS, check checkbox Exclude layouts and click the signPlus button below. Then, select a print layout from the Select print layout dialog in order to add it to the excluded layouts list.

If you want to exclude any layer or layer group from being published by the WMS, check checkbox Exclude Layers and click the signPlus button below. This opens the Select restricted layers and groups dialog, which allows you to choose the layers and groups that you don’t want to be published. Use the Shift or Ctrl key if you want to select multiple entries. It is recommended that you exclude from publishing the layers that you don’t need as this reduces the size of the WMS GetCapabilities response which leads to faster loading times on the client side.

If you check checkbox Use layer ids as name, layer ids will be used to reference layers in the GetCapabilities response or GetMap LAYERS parameter. If not, layer name or short name if defined (see QGIS Server Properties) is used.

You can receive requested GetFeatureInfo as plain text, XML and GML. The default is XML.

If you wish, you can check checkbox Add geometry to feature response. This will include the bounding box for each feature in the GetFeatureInfo response. See also the WITH_GEOMETRY parameter.

As many web clients can’t display circular arcs in geometries you have the option to segmentize the geometry before sending it to the client in a GetFeatureInfo response. This allows such clients to still display a feature’s geometry (e.g. for highlighting the feature). You need to check the checkbox Segmentize feature info geometry to activate the option.

You can also use the GetFeatureInfo geometry precision option to set the precision of the GetFeatureInfo geometry. This enables you to save bandwidth when you don’t need the full precision.

If you want QGIS Server to advertise specific request URLs in the WMS GetCapabilities response, enter the corresponding URL in the Advertised URL field.

Furthermore, you can restrict the maximum size of the maps returned by the GetMap request by entering the maximum width and height into the respective fields under Maximums for GetMap request.

You can change the Quality for JPEG images factor. The quality factor must be in the range 0 to 100. Specify 0 for maximum compression, 100 for no compression.

You can change the limit for atlas features to be printed in one request by setting the Maximum features for Atlas print requests field.

When QGIS Server is used in tiled mode (see TILED parameter), you can set the Tile buffer in pixels. The recommended value is the size of the largest symbol or line width in your QGIS project.

If one of your layers uses the Map Tip display (i.e. to show text using expressions) this will be listed inside the GetFeatureInfo output. If the layer uses a Value Map for one of its attributes, this information will also be shown in the GetFeatureInfo output.

2.4.2. WFS capabilities

In the WFS capabilities area you can select the layers you want to publish as WFS, and specify if they will allow update, insert and delete operations. If you enter a URL in the Advertised URL field of the WFS capabilities section, QGIS Server will advertise this specific URL in the WFS GetCapabilities response.

2.4.3. WCS capabilities

In the WCS capabilities area, you can select the layers that you want to publish as WCS. If you enter a URL in the Advertised URL field of the WCS capabilities section, QGIS Server will advertise this specific URL in the WCS GetCapabilities response.

2.4.4. Fine tuning your OWS

For vector layers, the Fields menu of the Layer ► Layer Properties dialog allows you to define for each attribute if it will be published or not. By default, all the attributes are published by your WMS and WFS. If you don’t want a specific attribute to be published, uncheck the corresponding checkbox in the WMS or WFS column.

You can overlay watermarks over the maps produced by your WMS by adding text annotations or SVG annotations to the project file. See the Инструменты аннотации section for instructions on creating annotations. For annotations to be displayed as watermarks on the WMS output, the Fixed map position checkbox in the Annotation text dialog must be unchecked. This can be accessed by double clicking the annotation while one of the annotation tools is active. For SVG annotations, you will need either to set the project to save absolute paths (in the General menu of the Project ► Properties… dialog) or to manually modify the path to the SVG image so that it represents a valid relative path.

2.5. Integration with third parties

QGIS Server provides standard OGC web services like WMS, WFS, etc. thus it can be used by a wide variety of end user tools.

2.5.1. Integration with QGIS Desktop

QGIS Desktop is the map designer where QGIS Server is the map server. The maps or QGIS projects will be served by the QGIS Server to provide OGC standards. These QGIS projects can either be files or entries in a database (by using Project ► Save to ► PostgreSQL in QGIS Desktop).

Furthermore, dedicated update workflow must be established to refresh a project used by a QGIS Server (ie. copy project files into server location and restart QGIS Server). For now, automated processes (as server reloading over message queue service) are not implemented yet.

2.5.2. Integration with MapProxy

MapProxy is a tile cache server and as it can read and serve any WMS/WMTS map server, it can be directly connected to QGIS server web services and improve end user experience.

2.5.3. Integration with QWC2

QWC2 is a responsive web application dedicated to QGIS Server. It helps you to build a highly customized map viewer with layer selection, feature info, etc.. Also many plugins are available like authentication or print service, the full list is available is this repository.