Introduction

Microsoft has issued an urgent call to action for .NET developers to swiftly revise their applications and developer workflows, as two critical domains utilized for installing .NET components—*dotnetcli.azureedge.net* and *dotnetbuilds.azureedge.net*—are slated for shutdown in the coming months. This is a direct result of the bankruptcy of Edgio, the content delivery network (CDN) provider responsible for hosting these domains.

Risk to Projects

The impending unavailability of these domains poses a significant risk to projects that depend on them, including those leveraging .NET installers, utilizing custom pipelines in GitHub Actions or Azure DevOps, and even Docker users with scripts referencing the now-retiring domains.

Microsoft's Statement

"Multiple CDN instances are in place for delivering .NET builds, many of which conclude with azureedge.net. These domains are operated by Edgio, which will soon halt operations due to bankruptcy. This necessitates our transition to new CDN solutions," stated Microsoft. The tech giant anticipates downtime for these domains in the near future, with a complete shutdown expected by early 2025.

Action Needed

To mitigate the potential disruptions, Microsoft strongly advises developers to comb through their code, scripts, and configurations for any references to *azureedge.net* and *dotnetcli.blob.core.windows.net*, urging them to replace these with *builds.dotnet.microsoft.com*.

Collaboration for Transition

During this transition phase, Microsoft's new CDN infrastructure will be supported by a collaboration of Edgio, Akamai, and Azure Front Door, as they work to finalize their distribution strategy with additional CDN providers. Teams involved in Continuous Integration/Continuous Deployment (CI/CD) must ensure that their implementations of GitHub Actions (actions/setup-dotnet) and Azure DevOps tasks are updated to versions compatible with the new domains. Notably, updates for Azure DevOps Server are anticipated in early 2025.

Firewall Configurations

It's also crucial to note that organizations need to reassess their firewall configurations to permit traffic from the new domains, particularly since even automatically updated configurations will require these adjustments.

Timing and Development Impact

Adding to the urgency of the situation, Microsoft has acknowledged the timing of this announcement, which unfortunately coincides with the holiday season—a period when many IT teams are operating with reduced personnel.

Domain Transfer Concerns

While some developers have expressed confusion over why Microsoft cannot simply transfer the domains and continue their use, Rich Lander, .NET Program Manager at Microsoft, clarified that this option was not made available to them. Interestingly, this contradicts statements made by Scott Hanselman of Microsoft, who confirmed that Microsoft currently owns the domains, ensuring no external party will access them. This ownership minimizes the risk of supply chain vulnerabilities for developers failing to migrate their applications; however, the lack of clarity regarding the urgency of the migration creates additional concerns.

Conclusion and Resources

For those who find themselves affected by this impending domain shift, updates and further discussions are available on a dedicated GitHub page, providing developers with resources to stay informed.

Call to Action

As the clock ticks down to potentially major disruptions in the .NET ecosystem, now is the time for developers to act swiftly and ensure their applications are future-proof against the looming changes. Don't wait until it's too late!