Thanks! The docs currently say this about the arch:

The tag format used by the images from this repository is mcr.microsoft.com/dotnet-buildtools/prereqs:<os-name>-<os-version>-<variant>-<architecture>
...
<architecture> - Architecture of the OS (amd64 shall be implied if not specified).

The folder structure used in src aligns with the tagging convention

If a Dockerfile is shared across multiple architectures, then the folder should be omitted.

Personally I like the policy of allowing -amd64 to be omitted from the tag format where it's implied, and keeping the simpler tags like azurelinux-3.0-net8.0-crossdeps-builder.

I propose we:

• Allow omitting amd64 from the tag names and folder structure, and undo Move all Dockerfiles to arch-specific dir #1047 for images where we take advantage of this option.
• Update docs to recommend the current pattern (-<target>) that we use for the cross-compilation images.

cc @richlander

Thanks! The docs currently say this about the arch:

The tag format used by the images from this repository is mcr.microsoft.com/dotnet-buildtools/prereqs:---
...
- Architecture of the OS (amd64 shall be implied if not specified).

The folder structure used in src aligns with the tagging convention

If a Dockerfile is shared across multiple architectures, then the folder should be omitted.

Personally I like the policy of allowing -amd64 to be omitted from the tag format where it's implied, and keeping the simpler tags like azurelinux-3.0-net8.0-crossdeps-builder.

I propose we:

• Allow omitting amd64 from the tag names and folder structure, and undo Move all Dockerfiles to arch-specific dir #1047 for images where we take advantage of this option.
• Update docs to recommend the current pattern (-<target>) that we use for the cross-compilation images.

cc @richlander

I don't like removing it from the directory name. Because there are some Dockerfiles which are truly multi-arch and so they have no architecture directory. Saying that an amd64 Dockerfile can get by without being contained in an amd64 directory causes confusion and ambiguity compared to the multi-arch ones.

For tags, I initially was ambivalent. But thinking more about it, I kind of feel it needs to be explicit because of the ambiguity that arises from it. One could imagine have multi-arch tags for our multi-arch Dockerfiles. And that would most definitely not have an arch in the tag name.

So I think the documented pattern should be changed to say that all architectures should be explicit both in tags and directories.

Thanks! Updated the readme to reflect this guidance and also mention the different pattern used for cross-arch images. I updated some of the alpine tags because the docs used alpine as an example.