Alpine floating tags have been temporarily rolled back to 3.21

[lbussell]

On 2025-07-08, the Alpine floating tags for .NET images were moved from 3.21 to 3.22 (announcement). Alpine 3.22 includes OpenSSL 3.5, the biggest OpenSSL release since OpenSSL 3.0. We have temporarily rolled those tags back to 3.21 because there is a significant incompatibility between Azure CosmosDB and OpenSSL 3.5. The team needs more time to investigate and respond.

The alpine floating tags are offered as a convenience for users. If we find significant compatibility issues with the new Alpine version, we will delay or revert changes to the floating tags. We offer fixed version tags for users that want more certainty.

Examples of both styles of Alpine tags:

• 8.0-alpine
• 8.0-alpine3.21
• 8.0-alpine3.22
• 9.0-alpine
• 9.0-alpine3.21
• 9.0-alpine3.22

Related issues:

• aspnet:8.0-alpine - OpenSSL 3.5.0 appears to cause frequent connection failures with Azure CosmosDB SDK running in Direct connection mode #6560
• Direct mode connections fail frequently when linked against OpenSSL >= 3.5.0 [Alpine Linux 3.22] Azure/azure-cosmos-dotnet-v3#5302