Remote Execution Guide¶
Desktop GUI tests usually require active desktop to move mouse cursor and type some keys into a focused window. That completely blocks local machine from normal usage.
But running tests on a remote machine is a challenge. This guide collected known issues and solutions to control a remote machine with GUI tests.
Windows Remote Desktop features¶
Remote Desktop (RDP) provides virtual active desktop to remote machine with Windows OS. There are 2 potential issues:
- If RDP window is minimized, there is no active desktop on remote PC by default.
- If RDP is disconnected, the desktop is locked out.
In both cases any GUI automation jobs will fail (if you don’t use some tricks described below). The workarounds are well described in TestComplete documetation:
Running a GUI program in a Docker image is not an option since
mcr.microsoft.com/windows/servercore:1709 so currently the test machine needs to be either
physical or virtual.
VNC Server software¶
There is more simple way to avoid above issues: using VNC server software (for example, Tight VNC). It works as a pair of client and server. VNC server also provides active desktop on a remote machine.
- This is a non-virtual desktop so working with native screen resolution on a remote PC may require updating video drivers.
- Minimizing or disconnecting VNC client doesn’t destroy active desktop (by default!).
- This is a cross-platform solution (VNC server is a native part of macOS and available on Linux).
The only problem you may face with:
- Using Remote Desktop (RDP) may break VNC server benefits and you have to restart remote PC or apply RDP workarounds described above.
Other remote access software¶
If anyone tried to run GUI tests/automation remotely using Team Viewer, PowerBI desktop or any other virtual desktop software, feel free to add more details into this guide.
Tricks to run automation on a locked machine¶
For some applications it’s possible to run GUI automation on a locked machine, but it requires using special methods. First it’s worth listing methods that don’t work on a locked machine:
- click_input and all other mouse click and press methods ending with
- set_focus as it uses
- type_keys for native keyboard input.
- Direct usage of modules mouse and keyboard.
Some other methods may not work also, but it depends on application.
There are few methods for silent text input in
- send_chars (symbols only; special key combinations do not work)
- send_keystrokes (some special key combinations may work)
There is another useful method to enter string at once (available for both backends, usually for edit box only):
- “uia”: set_edit_text (enter text as is, no modifiers supported)
- “win32”: set_edit_text
Start remote script using agent based CI¶
When your script is ready and you can run it on a remote machine manually, it’s time to automate the last step: trigger running the script from local machine or from CI server.
If you have internal hosted CI (for example, Jenkins), probably target machine is already connected to Jenkins master using an agent. There are three ways to connect agent:
- Run agent as a service: GUI tests won’t work in this case because GUI can’t be even created when running as a service. Even if the service is allowed to interact with the desktop the interactive Station and Desktop objects availability is not guaranteed.
- Run agent through SSH: GUI tests won’t work.
- Run agent as a normal application. This is the only working case!
Integration with Jenkins¶
Jenkins is an open source automation server. Application testing with pywinauto can be embedded in a Jenkins Pipeline running on a Windows node.
Jenkins master and nodes configuration is beyond the scope of this document so we assume that a Jenkins master is running on some OS and drives a Jenkins node running whatever Windows flavour you want to test on.
To run GUI tests the application under test needs to be connected to a Desktop; thìs in turn means that an interactive Station must be available.
The simplest solution is to setup a dedicated machine and configure windows to autologin and create a scheduled task to run the Jenkins slave agent upon login.
More details can be found i.e. on stackoverflow.
The scheduled task should be a batch file like the following example
java -jar slave.jar -jnlpUrl https://<JENKINS_HOST>/computer/<NODE_NAME>/slave-agent.jnlp -workDir <WORKDIR> -secret <SECRET>
<JENKINS_HOST>is Jenkins master host:port
<WORKDIR>is the Jenkins slave root on filesystem
<SECRET>is the node secret that can be found in
slave-agent.jnlp. Note that the file can be downloaded only from the node itself. If Jenkins is configured without security this option won’t be required
Once the Jenkins slave is online GUI programs can be run and tested with pywinauto. RDP connections create and destroy desktops so they might interfere with the test process and should be avoided, see Windows Remote Desktop features.
Start remote script directly¶
This chapter is inspired by issue #401 (special thanks to yangliang003).
First option is PsExec (does not work with Jenkins) or PAExec (fully compatible opensource). Thanks to this post on StackExchange.
Ansible has PsExec plugin that simplifies it. Playbook example:
--- - name: test ra module hosts: ***** tasks: - name: run GUI automation win_psexec: command: python pywinauto_example.py executable: C:\Windows\PSTools\psexec.exe interactive: yes username: admin password: ****** hostnames: ******
Windows Scheduler is also capable to start jobs with GUI interaction support.
There is easy way to schedule the task from
Schtasks /Create /tn my_task /tr c:\temp\my_task.bat /sc ONCE /st hh:mi:ss /sd yyyy/mm/dd