matiasma / avdsessionhostreplacer

Welcome to Azure Virtual Desktop (AVD) Session Host Replacer

Overview

This tool automates the deployment and replacement of session hosts in an Azure Virtual Desktop host pool.

The best practice for AVD recommends replacing the session hosts instead of maintaining them, the AVD Session Host Replacer helps you manage the task of replacing old session hosts with new ones automatically.

Getting started

Deployment Type	Link
Azure Portal UI
Command line (Bicep/ARM)

How it works?

There are two criteria for replacing a session host,

1. Image Version: Is there a new image version available? If so, we create a new session host with the new image version. This can be from Marketplace or Gallery Image Definition.
2. Session Host VM Age: If the session host is older than a certain age, default is 45 days, we create a new session host and drain the old one.

The core of an AVD Session Host Replacer is an Azure Function App built using PowerShell, the function is triggered every hour to check each session host against the above criteria.

To deploy new session hosts, the function uses an ARM Template that is stored as a Template Spec at deployment time.

When deleting an old session host, the function will check if it has existing sessions and,

1. Place the session host drain mode.
2. Send a notification to all sessions.
3. Add a tag to the session host with a timestamp
4. Delete the session host once there are no sessions or the grace period has passed.
   • Delete VM
   • Remove from Host Pool
   • (If Entra Joined) Delete device from Entra ID

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.