How to: "warm up" an environment using PowerShell and TeamCity

Prior to running some tests on a .NET web application, we wanted to send a request to the environment to “warm it up” – so that the initial start of the application pool would be completed before the tests started running.

Solution

• Select a URL that you can reasonably expect to hit as a smoke test
• Create a TeamCity build configuration
• Add a build step to the configuration of type “Powershell Script”
• Select an in-line script
• Add the following powershell:

Invoke-WebRequest -Uri http://theURLToHit -UseDefaultCredentials

Now the build step will hit the URI using the build agent’s credentials, and the command will return when the result does (with a 200 after the app pool has started up).

Happy deployments!