refactor osbuild manifests to reduce definition duplication

[dustymabe]

Previously we had a bunch of duplications in the manifests for two reasons:

1. For vimdiff, since I thought we needed duplicated definitions due to minute differences between the architectures because...
2. I didn't understand the mpp-if conditional could be used at lower levels rather than just the stage/node level.

AI helped me come to this realization:

mpp-if already works at a lower level than stage/node level. Looking at the implementation, there's nothing restricting it to stages. The _process_format method (line 1317) recursively
walks the entire YAML tree — dicts and lists alike — and evaluates mpp-if anywhere it encounters it as a dict value. Specifically:

1. In a dict value (lines 1403-1418): For every key in a dict, if the value is an mpp-if node, it evaluates it and either replaces the value with the then/else result, or deletes the
   key entirely if the chosen branch doesn't exist (remove=True on line 1358 when neither then nor else matches).
2. In a list element (lines 1420-1432): For every element in a list, if it's an mpp-if node, it evaluates it and either replaces the element or removes it from the list (lines 1431-1432)
   .

So you can use mpp-if at the individual key level inside a dict.

The commits in this PR each march towards sharing definitions across architectures. With this we end up with:

 8 files changed, 778 insertions(+), 3137 deletions(-)

The important thing here is that we can be comfortable with such a large change because the changes can be 100% verified by using osbuild-mpp to generate the osbuild json and verify it's exactly the same as before the commits in this PR.

I've done this already for x86_64 and will do so for the other architectures if people think this PR looks good.

[gemini-code-assist]

Code Review

This pull request refactors the osbuild manifests by consolidating redundant pipeline definitions into shared include files: build.common.ipp.yaml, build.raw-image.ipp.yaml, and build.raw-4k-image.ipp.yaml. Architecture-specific manifests for aarch64, ppc64le, riscv64, s390x, and x86_64 have been updated to import these common pipelines, using conditional logic to handle platform-specific configurations such as bootloaders, kernel options, and mount points. I have no feedback to provide as the changes correctly centralize the build logic.

[jbtrystram]

Neat. But why spend time on this when we'll move to image builder and get rid of all of these?

[dustymabe]

Neat. But why spend time on this when we'll move to image builder and get rid of all of these?

A few reasons.

• AI made this easy.
• It should make osbuild: use bootc install to deploy the container #4224 easier to review (i.e. diffing raw-image and raw-4k-image definitions should be easier)
• I think now with the insight about mpp-if capability we can get by without duplicating entire manifests like your PR does osbuild: use bootc install to deploy the container #4224. To be fair I told you to do this originally because I thought it was the best way.
• I know image builder is the end goal but it's not clear to me if that will happen in 12 weeks or 12 months.

[dustymabe]

I've done this already for x86_64 and will do so for the other architectures if people think this PR looks good.

verified that for all architectures the generated JSON is the same before/after these changes.

This patch helped:

Details

diff --git a/src/runvm-osbuild b/src/runvm-osbuild
index 2688248d8..d4d105ee6 100755
--- a/src/runvm-osbuild
+++ b/src/runvm-osbuild
@@ -103,11 +103,16 @@ orig_outdir=$outdir
 outdir=cache/osbuild/out
 
 processed_json=$(mktemp -t osbuild-XXXX.json)
+myarch=
+
+for myarch in x86_64 aarch64 riscv64 ppc64le s390x; do
+processed_json="./osbuild-mpp-out-${myarch}.json"
+mppyaml="/usr/lib/coreos-assembler/osbuild-manifests/coreos.osbuild.${myarch}.mpp.yaml"
 
 # Run through the preprocessor
 # Note: don't quote the size arguements since they are numbers, not strings
 set -x; osbuild-mpp                                       \
-    -D arch=\""$(arch)"\"                                 \
+    -D arch=\""${myarch}"\"                                 \
     -D artifact_name_prefix=\""${artifact_name_prefix}"\" \
     -D build_version=\""${build_version}"\"               \
     -D ociarchive=\""${ostree_container}"\"               \
@@ -121,6 +126,9 @@ set -x; osbuild-mpp                                       \
     -D rootfs_size_mb="${rootfs_size_mb}"                 \
     "${mppyaml}" "${processed_json}"
 set +x
+done
+
+exit 1
 
 log_disk_usage
 

[jbtrystram]

LGTM