[Breaking change]: .NET SDK Containers default to use the latest tag instead of $(Version)

[baronfel]

Description

The default image tag used for .NET SDK-built Containers changed from the value of the Version of the Project to the value latest in .NET 8.0.100 preview 6 with #36404.

Version

.NET 8 Preview 6

Previous behavior

Previously, the image would be built with a tag value of $(Version), which enabled changing the tag based on the same value that the rest of the .NET ecosystem uses.

New behavior

Now, the generated image will have the latest tag in all cases.

Type of breaking change

• Binary incompatible: Existing binaries may encounter a breaking change in behavior, such as failure to load or execute, and if so, require recompilation.
• Source incompatible: When recompiled using the new SDK or component or to target the new runtime, existing source code may require source changes to compile successfully.
• Behavioral change: Existing binaries may behave differently at run time.

Reason for change

This change aligns the default containerization experience with the developer experiences for other container tooling like the Docker CLI, and makes the dev inner-loop of repeated container publishes in an iterative loop more easy to use with tools like Docker Compose, because the version remains stable.

Recommended action

Explicitly set the version if you need it. The easiest way would be to set the ContainerImageTag property on the command line to an explicit version, e.g. /p:ContainerImageTag=1.2.3, but you can also programmatically set the value the same as you would with any other MSBuild property. In a project file you can continue to use the $(Version) property by adding the following code:

<PropertyGroup>
  <ContainerImageTag>$(Version)</ContainerImageTag>
</PropertyGroup>

Feature area

SDK

Affected APIs

No response

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Associated WorkItem - 142258