If you are using Azure DevOps to deploy resources to Azure then you probably know the pain of using service principles for your service connection. Using a service principle involves storing the credentials for this in Azure DevOps. Assuming you’re following good security principles and having an expiry on the service principle secret you’re probably going to forget to renew it at least once, and your deployments will grind to a halt.
We’ve looked previously at using the open source tool https://www.packer.io/intro/ from Hashicorp to automate the process of building Azure VM images, which can then be consumed using either single VMs or VM scale sets. By using this tool and some PowerShell DSC scripts, we have been able to automate the process of spinning up a VM in Azure, installing the required software and configuration, running Sysprep and capturing an image. So far we have done this by running our Packer script manually from the command line.
