11.1. Lesson: Install QGIS Server

The goal for this lesson: To learn how to install QGIS Server on Debian Stretch. With negligible variations you can also follow it for any Debian based distribution like Ubuntu and its derivatives.

Megjegyzés

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.

11.1.1. moderate Follow Along: Install from packages

In this lesson we’re going to do only the install from packages as shown here .

Install QGIS Server with:

apt install qgis-server --no-install-recommends --no-install-suggests

# if you want to install server plugins, also:
apt install python-qgis

QGIS Server should be used in production without QGIS Desktop (with the accompanying X Server) installed on the same machine.

11.1.2. moderate Follow Along: QGIS Server Executable

The QGIS Server executable is qgis_mapserv.fcgi. You can check where it has been installed by running find / -name 'qgis_mapserv.fcgi' which should output something like /usr/lib/cgi-bin/qgis_mapserv.fcgi.

Optionally, if you want to do a command line test at this time you can run the /usr/lib/cgi-bin/qgis_mapserv.fcgi command which should output something like:

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>

This is a good thing, it tells you we’re on the right track as the server is saying that we haven’t asked for a supported service. We’ll see later on how to make WMS requests.

11.1.3. hard HTTP Server Configuration

In order to access on the installed QGIS server from an Internet Browser we need to use an HTTP server. The Apache HTTP Server installation process is detailed in Apache HTTP Server section.

Megjegyzés

If you installed QGIS Server without running an X Server (included in Linux Desktop) and if you also want to use the GetPrint command then you should install a fake X Server and tell QGIS Server to use it. You can do that by following the Xvfb installation process.

11.1.4. moderate Follow Along: Create another virtual host

Let’s create another Apache virtual host pointing to QGIS Server. You can choose whatever name you like (coco.bango, super.duper.training, example.com, etc.) but for simplicity sake we’re going to use myhost.

  • Let’s set up the myhost name to point to the localhost IP by adding 127.0.0.1 x to the /etc/hosts with the following command: sh -c "echo '127.0.0.1 myhost' >> /etc/hosts" or by manually editing the file with gedit /etc/hosts.

  • We can check that myhost points to the localhost by running in the terminal the ping myhost command which should output:

qgis@qgis:~$ ping myhost
PING myhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.024 ms
64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.029 ms

  • Let’s try if we can access QGIS Server from the myhost site by doing: curl http://myhost/cgi-bin/qgis_mapserv.fcgi or by accessing the url from your Debian box browser. You will probably get:

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p>The requested URL /cgi-bin/qgis_mapserv.fcgi was not found on this server.</p>
<hr>
<address>Apache/2.4.25 (Debian) Server at myhost Port 80</address>
</body></html>

  • Apache doesn’t know that he’s supposed to answer requests pointing to the server named myhost. In order to setup the virtual host the simplest way would be to make a myhost.conf file in the /etc/apache2/sites-available directory that has the same content as qgis.demo.conf except for the ServerName line that should be ServerName myhost. You could also change where the logs go as otherwise the logs for the two virtual hosts would be shared but this is optional.

  • Let’s now enable the virtual host with a2ensite myhost.conf and then reload the Apache service with service apache2 reload.

  • If you try again to access the http://myhost/cgi-bin/qgis_mapserv.fcgi url you’ll notice everything is working now!

11.1.5. In Conclusion

You learned how to install different QGIS Server versions from packages, how to configure Apache with QGIS Server, on Debian based Linux distros.

11.1.6. What’s Next?

Now that you’ve installed QGIS Server and it’s accessible through the HTTP protocol, we need to learn how to access some of the services it can offer. The topic of the next lesson is to learn how to access QGIS Server WMS services.