OpenSUSE Hackweek VIII - New WebYaST Demo Appliance

I decided to work on WebYaST home page and finish the WebYaST demo appliance.

Some time ago we had a workshop where we decided to create cool web pages for our projects. We started with WebYaST. The goal is to create a nice looking web presentation.

And we want to have some WebYaST demo so users could easily try it without any setup or installation. So we decided to create a WebYaST demo appliance in SUSE Studio which can be used as a LiveCD or USB stick or even directly in Studio testdrive in a web browser (no need to download anything!).

Including WebYaST in an openSUSE-12.1 SUSE Studio Appliance

This is really easy as Studio has WebYaST support built-in, just go into Configuration -> Appliance tab and check Enable WebYaST check box at the very bottom of the page. And that's it!

Studio will add all needed WebYaST packages, opens port at firewall (54984) and autostarts WebYaST at boot.

But if we want to have a really nice demo we still need to do some improvements...

Appliance Fine-tuning

Originally I started with KDE desktop but WebYaST basically does not depend on any desktop environment so I switched to LXDE which takes less space and should run faster than KDE (especially on slower machines).

SUSE Studio supports autologin configuration (Configuration -> Desktop) so users do not have to enter any password to start graphical session, that's nice.

Another nice feature is automatic application start,  so we can easily start Firefox. The only problem was that in testdrive WebYaST was sometimes started later than Firefox which obviously displayed error page. This is solved by 5 second delay before starting Firefox.

Importing WebYaST Certificate into Firefox

This was the hard part and it's quite tricky. When you first time connect to a running WebYaST instance in Firefox you'll see a certificate warning. The problem is that WebYaST generates a self-signed certificate (when there is no existing certificate yet) which is not trusted so Firefox displays that warning. And this might be scary for beginner users, we want our users to try WebYaST without any doubts...

Then I found certutil tool available in mozilla-nss-tools package in openSUSE. This can be used to import a certificate to Firefox from command line. So for WebYaST this means running this command for the default user:

# certutil -A -n "Webyast certificate" -t "C,," -d /home/tux/.mozilla/firefox/*.default \
-i /etc/lighttpd/certs/webyast.pem

(See certutil --help for more details.)

The only problem is that Firefox uses profiles (named configurations) stored at random generated directory which is created at first start. And that directory must exist before executing the certutil command.

This is solved by overlay files in Studio, there is a prepared directory with the default Firefox profile.

Server Name in the Generated certificate

During tests I found out that there is a problem with certificate server name and the URL. Firefox displayed a certificate error when opening https://localhost:54984 with message saying that the certificate is valid for linux-foobar server only (with foobar replaced by some random characters).

The problem is that the random hostname is automatically generated and we cannot easily change that in the URL for Firefox.

The trick is to use IP address directly instead of a host name. The WebYaST certificate in the demo appliance is generated for host 127.0.0.1 and URL for Firefox is set to https://127.0.0.1:54984.

See yastwc overlay file for all certificate related changes.

The Final WebYaST Demo Appliance

The final WebYaST demo appliance is available in SUSE Studio Gallery. You can easily try WebYaST as a LiveCD/LiveUSB stick or directly in your browser in Studio testdrive.

And how to use it? That's really simple! Just boot the image, wait until Firefox with WebYaST login dialog opens. Then use root user name with linux password to log into WebYaST.

Have a lot of fun!