Azure DevTest Labs: Introducing formulas to create VMs productively
Posted on 05 April 2016
In addition to custom images and Azure Marketplace images, Azure DevTest Labs enables a new way to create VMs: through formulas. A formula is a template in DevTest Labs that captures all the settings that you specify when you create a lab VM. It provides all the following benefits to make VM provisioning even more productive and flexible:
- Unlike a static VM image, changes in the environment can be captured on the fly through formulas, thanks to the lab artifacts. It basically means no more extra cost for you to generate or maintain new custom image files. For example, if you want a VM installed with the latest bits from your release pipeline, you can simply specify an artifact in the formula that deploys the latest bits (together with other settings such as a target base image). Whenever you use this formula to create VMs, you always get the latest bits deployed to the VM. You don't need to create new custom images every time when new bits are available from your pipeline.
- Formulas can define default/recommended settings that custom images cannot provide, including VM sizes and the virtual network.
- Because all the settings saved in a formula are shown as default values, the values can be updated when you use them to create a VM. This gives you more flexibility to feed different needs. For example, you can simply change the base image between different versions of Windows (or Linux) for compatibility testing, but keep all the other VM creation settings (artifacts, virtual networks, etc.) the same.