Where possible, you shouldn’t log in to a server manually and make changes. Software doesn’t need to be installed by clicking buttons in a GUI, and updates don’t need to be made to configuration files in a text editor. These manual actions introduce an opportunity for errors to occur, which can result in misconfigurations and application failures. If you want to replicate the configuration of a server, can you remember all the steps that were required to get the existing server up and running? What if you need to do it again in six months?
In chapter 16, we touched on a way to automatically check for and apply updates to servers. This magic happened with the use of Azure Automation. In this chapter, we’ll examine how you can create, run, and edit runbooks, and use PowerShell Desired State Configuration to install applications and configure servers automatically.