QGIS ca și Server de Date OGC¶

Exemplu de instalare pe Debian Squeeze¶

At this point, we will give a short and simple sample installation how-to for a minimal working configuration using Apache2 on Debian Squeeze. Many other OSs provide packages for QGIS Server, too. If you have to build it all from source, please refer to the URLs above.

În primul rând, se adaugă următorul depozit GIS pentru debian astfel:

$ cat /etc/apt/sources.list.d/debian-gis.list
deb http://qgis.org/debian trusty main
deb-src http://qgis.org/debian trusty main

$ # Add keys
$ sudo gpg --recv-key DD45F6C3
$ sudo gpg --export --armor DD45F6C3 | sudo apt-key add -

$ # Update package list
$ sudo apt-get update && sudo apt-get upgrade

Acum, instalați QGIS-Server:

$ sudo apt-get install qgis-server python-qgis

Installation of a HelloWorld example plugin for testing the servers. You 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-get install unzip
$ sudo unzip master.zip
$ sudo mv qgis-helloserver-master HelloServer

Instalați serverul Apache într-o gazdă virtuală separată, care monitorizează portul 80. Activați modulul de rescriere pentru a permite autentificarea antetelor HTTP BASIC:

$ sudo a2enmod rewrite
$ cat /etc/apache2/conf-available/qgis-server-port.conf
Listen 80
$ sudo a2enconf qgis-server-port

Aceasta este configurația gazdei virtuale, stocate în /etc/apache2/sites-available/001-qgis-server.conf :

<VirtualHost *:80>
  ServerAdmin webmaster@localhost
  DocumentRoot /var/www/html

  ErrorLog ${APACHE_LOG_DIR}/qgis-server-error.log
  CustomLog ${APACHE_LOG_DIR}/qgis-server-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"
  FcgidInitialEnv QGIS_DEBUG 1
  FcgidInitialEnv QGIS_SERVER_LOG_FILE /tmp/qgis-000.log
  FcgidInitialEnv QGIS_SERVER_LOG_LEVEL 0
  FcgidInitialEnv QGIS_PLUGINPATH "/opt/qgis-server/plugins"

  # ABP: needed for QGIS HelloServer plugin HTTP BASIC auth
  <IfModule mod_fcgid.c>
      RewriteEngine on
      RewriteCond %{HTTP:Authorization} .
      RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
  </IfModule>

  ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
  <Directory "/usr/lib/cgi-bin">
      AllowOverride All
      Options +ExecCGI -MultiViews +FollowSymLinks
      # for apache2 > 2.4
      Require all granted
      #Allow from all
  </Directory>
 </VirtualHost>

Acum activați gazda virtuală și reporniți Apache:

$ sudo a2ensite 001-qgis-server
$ sudo service apache2 restart

Testați serverul cu plugin-ul HelloWorld:

$ wget -q -O - "http://localhost/cgi-bin/qgis_mapserv.fcgi?SERVICE=HELLO"
HelloServer!

Puteți arunca o privire la comanda GetCpabilities a serverului QGIS la: http://localhost/cgi-bin/qgis_mapserv.fcgi?SERVICE=WMS&VERSION=1.3.0&REQUEST=GetCapabilities

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

Crearea unui WMS/WFS/WCS dintr-un proiect QGIS¶

Pentru a crea un nou Server WMS, WFS or sau WCS QGIS, trebuie să creăm un fișier de proiect QGIS, în care să existe câteva date. În continuare, vom folosi fișierul shape ‘Alaska’, al setului de date eșantion din QGIS. În QGIS definiți culorile și stilurile straturilor, precum și CRS-ul proiectului, dacă nu ați făcut deja acest lucru.

Figure Server 2:

Definițiile unui proiect de Server WMS/WFS/WCS QGIS (KDE)

Then, go to the OWS Server menu of the Project ‣ 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 Service capabilities, QGIS Server will use the information given in the wms_metadata.xml file located in the cgi-bin folder.

Capabilităţi WMS

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 CRS restrictions, you can restrict in which coordinate reference systems (CRS) QGIS Server will offer to render maps. Use the button below to select those CRS from the Coordinate Reference System Selector, or click Used to add the CRS used in the QGIS project to the list.

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

If you want to exclude any layer or layer group from being published by the WMS, check Exclude Layers and click the 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 at once.

Puteți primi rezultatul solicitării GetFeatureInfo sub formă de text simplu, XML și GML. XML este implicit, textul sau formatul GML depinzând de formatul de ieșire ales pentru cererea GetFeatureInfo.

If you wish, you can check Add geometry to feature response. This will include in the GetFeatureInfo response the geometries of the features in a text format. 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.

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 his attributes, also this information will be shown in the GetFeatureInfo output.

QGIS support the following request for WMS service:

• GetCapabilities
• GetMap
• GetFeatureInfo

• GetLegendGraphic (profilul SLD)

• DescribeLayer (profilul SLD)

• GetStyles (profilul QGIS personalizat)

Capabilități WFS

In the WFS capabilities area, you can select the layers that you want to publish as WFS, and specify if they will allow the 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.

QGIS support the following request for WFS service:

• GetCapabilities
• DescribeFeatureType
• GetFeature
• Transaction

Capabilități WCS

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.

Now, save the session in a project file alaska.qgs. To provide the project as a WMS/WFS, we create a new folder /usr/lib/cgi-bin/project with admin privileges and add the project file alaska.qgs and a copy of the qgis_mapserv.fcgi file - that’s all.

Acum vom testa proiectul nostru WMS, WFS și WCS. Adăugați în QGIS WMS, WFS și WCS așa cum este descris în Încărcarea Straturilor WMS/WMTS, Client WFS și WFS-T și Client WCS, apoi încărcați datele. URL-ul este:

http://localhost/cgi-bin/project/qgis_mapserv.fcgi

QGIS support the following request for WCS service:

• GetCapabilities
• DescribeCoverage
• GetCoverage