[llvm] [libc++] Add Docker images to support incoming pre-merge CI transition (PR #144597)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-github-workflow

Author: Louis Dionne (ldionne)

<details>
<summary>Changes</summary>

As described in [1], we are transitioning to the LLVM-wide pre-merge CI infrastructure. As part of this change, we need a way to specify which Docker image to use from the sources, and we can't do that from the workflow files directly due to a Kubernetes bug. Instead, the runner groups are going to pick up the Docker image specified in this json file as it appears on the `main` branch of the official LLVM Github repository.

[1]: https://discourse.llvm.org/t/rfc-migrating-libc-premerge-testing-to-new-llvm-premerge-testing-infrastructure

---
Full diff: https://github.com/llvm/llvm-project/pull/144597.diff


1 Files Affected:

- (added) .github/workflows/libcxx-docker-images.yml (+12) 


``````````diff
diff --git a/.github/workflows/libcxx-docker-images.yml b/.github/workflows/libcxx-docker-images.yml
new file mode 100644
index 0000000000000..9366d825ba415
--- /dev/null
+++ b/.github/workflows/libcxx-docker-images.yml
@@ -0,0 +1,12 @@
+# This file defines the Docker images used by various self-hosted runner groups used
+# in the libc++ pre-merge testing pipeline.
+#
+# The images are specified this way instead of being in the workflow file due to a
+# Kubernetes bug, as described in https://discourse.llvm.org/t/rfc-migrating-libc-premerge-testing-to-new-llvm-premerge-testing-infrastructure.
+#
+# When updating this file, the self-hosted runner sets are going to pick up the
+# specified image after a short delay. The Docker images used are always the
+# ones on the 'main' branch of the official LLVM GitHub repository.
+libcxx-runner-set-current: ghcr.io/llvm/libcxx-linux-builder:b060022103f551d8ca1dad84122ef73927c86512
+libcxx-runner-set-next: none
+libcxx-runner-set-release: ghcr.io/llvm/libcxx-linux-builder:d8a0709b1090350a7fe3604d8ab78c7d62f10698

``````````

</details>


https://github.com/llvm/llvm-project/pull/144597