How to get Sikuli working in headless mode

Question

If we have a headless test server running sikuli (both ubuntu and windows configurations needed), how to get it work without a physical monitor and preferably for as many sc

Answer 1

I got SikuliX working in a true headless mode in GCE with a Windows 2016 client system. It takes some duct tape and other Rube Goldberg contraptions to work, but it can be done.

The issue is that, for GCE (and probably AWS and other cloud environment Windows clients), you don't have a virtual video adapter and display, so, unless there's an open RDP connection to the client, it doesn't have a screen, and SikuliX/OpenCV will get a 1024x768 black desktop, and fail.

So, the question is, how to create an RDP connection without having an actual screen anywhere. I did this using Xvfb (X Windows virtual frame buffer). This does require a second VM, though. Xvfb runs on Linux. The other piece of the puzzle is xfreerdp 2.0. The 2.x version is required for compatibility with recent versions of Windows. 1.x is included with some Linux distros; 2.x may need to be built from sources, depending on what flavor Linux you're using. I'm using CentOS, which did require me to build my own.

The commands to establish the headless RDP session, once the pieces are in place, look something like this:

/usr/bin/Xvfb :0 -screen 0 1920x1080x24 &
export DISPLAY=:0.0
/usr/local/bin/xfreerdp /size:1920x1080 /u:[WindowsUser] /p:"[WindowsPassword]" /v:[WindowsTarget]

In our environment we automated this as part of the build job kicked off by Jenkins. For this to work under the Jenkins slave, it was also necessary to run the Jenkins slave as a user process, rather than a service... this can be accomplished by enabling auto admin login and setting the slave launch script as a run (on logon) command.