feat: restructure nova understack

components/images-openstack.yaml

@@ -48,19 +48,19 @@ images:
     neutron_netns_cleanup_cron: "ghcr.io/rackerlabs/understack/neutron:2026.1"
 
     # nova
-    nova_api: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_cell_setup: "ghcr.io/rackerlabs/understack/nova:2026.1"
+    nova_api: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_cell_setup: "ghcr.io/rackerlabs/understack/nova:pr-2173"
     nova_cell_setup_init: "ghcr.io/rackerlabs/understack/openstack-client:2025.2"
-    nova_compute: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_compute_ironic: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_compute_ssh: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_conductor: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_db_sync: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_novncproxy: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_novncproxy_assets: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_scheduler: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_spiceproxy: "ghcr.io/rackerlabs/understack/nova:2026.1"
-    nova_spiceproxy_assets: "ghcr.io/rackerlabs/understack/nova:2026.1"
+    nova_compute: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_compute_ironic: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_compute_ssh: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_conductor: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_db_sync: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_novncproxy: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_novncproxy_assets: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_scheduler: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_spiceproxy: "ghcr.io/rackerlabs/understack/nova:pr-2173"
+    nova_spiceproxy_assets: "ghcr.io/rackerlabs/understack/nova:pr-2173"
     nova_service_cleaner: "docker.io/openstackhelm/ceph-config-helper:latest-ubuntu_jammy"
 
     # placement

containers/nova/Dockerfile

@@ -1,15 +1,31 @@
 # syntax=docker/dockerfile:1
 
 ARG OPENSTACK_VERSION="required_argument"
-FROM quay.io/airshipit/nova:${OPENSTACK_VERSION}-ubuntu_noble
-
-RUN apt-get update && \
-    apt-get install -y --no-install-recommends \
-        patch \
-        quilt \
-    && apt-get clean && rm -rf /var/lib/apt/lists/*
-
-COPY containers/nova/patches /tmp/patches/
-RUN cd /var/lib/openstack/lib/python3.12/site-packages && \
-    QUILT_PATCHES=/tmp/patches quilt push -a
-COPY python/nova-understack/ironic_understack  /var/lib/openstack/lib/python3.12/site-packages/nova/virt/ironic_understack
+FROM quay.io/airshipit/nova:${OPENSTACK_VERSION}-ubuntu_noble AS build
+
+COPY --from=ghcr.io/astral-sh/uv:latest /uv /uvx /bin/
+
+# renovate: name=openstack/nova repo=https://github.com/rackerlabs/nova.git branch=understack/2026.1
+ARG NOVA_GIT_REF=1602d7db7a3fe4930668f8a6534782adf4fbe572
+ADD --keep-git-dir=true https://github.com/rackerlabs/nova.git#${NOVA_GIT_REF} /src/nova
+RUN git -C /src/nova fetch --unshallow --tags
+
+ARG OPENSTACK_VERSION="required_argument"
+ADD https://releases.openstack.org/constraints/upper/${OPENSTACK_VERSION} /upper-constraints.txt
+
+RUN --mount=type=cache,target=/root/.cache/uv \
+    uv pip install \
+      --upgrade \
+      --constraint /upper-constraints.txt \
+        /src/nova
+
+ARG OPENSTACK_VERSION="required_argument"
+FROM quay.io/airshipit/nova:${OPENSTACK_VERSION}-ubuntu_noble AS final
+
+RUN rm -rf /var/lib/openstack
+COPY --from=build --link /var/lib/openstack /var/lib/openstack
+
+# Copy ironic_understack into Nova virt drivers
+# This copies the directory as-is; no explicit dependencies are installed.
+# Dependencies (requests, oslo_config) are already provided by Nova's installation.
+COPY python/nova-understack/ironic_understack /var/lib/openstack/lib/python3.12/site-packages/nova/virt/ironic_understack

containers/nova/README.md

@@ -0,0 +1,106 @@
+# Nova Patches
+
+Patches are derived from cherry-picking patches to the stable series we follow.
+
+[https://github.com/rackerlabs/nova](https://github.com/rackerlabs/nova)
+
+The branch for these are `understack/$OPENSTACK_VERSION`
+
+## Initial Setup - Creating understack/2026.1 Branch
+
+If the `understack/2026.1` branch doesn't exist yet, create it:
+
+```bash
+git clone https://github.com/openstack/nova
+cd nova
+git checkout --track origin/stable/2026.1
+git remote add rackerlabs https://github.com/rackerlabs/nova
+git checkout -b understack/2026.1
+git push -u rackerlabs understack/2026.1
+```
+
+## To clone everything down (after branch is created)
+
+```bash
+git clone https://github.com/openstack/nova
+git checkout --track origin/stable/2026.1
+git remote add rackerlabs https://github.com/rackerlabs/nova
+git fetch rackerlabs
+git checkout --track rackerlabs/understack/2026.1
+```
+
+## Adding patches is done via `git cherry-pick`
+
+```bash
+git checkout understack/2026.1
+git cherry-pick GITISH_TO_PORT
+git push rackerlabs understack/2026.1
+```
+
+## Creating the next stable series
+
+```bash
+git checkout --track origin/stable/2026.2
+git checkout -b understack/2026.2
+```
+
+## Rebasing to keep things clean
+
+```bash
+git checkout stable/2026.1
+git pull -p
+git checkout understack/2026.1
+git rebase stable/2026.1
+git push rackerlabs understack/2026.1
+```
+
+## Updating the container
+
+```bash
+git checkout understack/2026.1
+git show
+# ensure the git-ish in the Dockerfile matches
+```
+
+## Backporting patches from upstream master
+
+To backport a patch from upstream master (or another branch) to understack/2026.1:
+
+```bash
+# Fetch all branches from upstream (openstack/nova)
+# This fetches master, stable branches, and all other refs
+git fetch origin
+
+# Fetch all branches from rackerlabs fork
+git fetch rackerlabs
+
+# Checkout the understack branch
+git checkout understack/2026.1
+
+# Cherry-pick the commit from master
+# You can get the commit hash from the PR or upstream repository
+git cherry-pick <UPSTREAM_COMMIT_HASH>
+
+# If there are conflicts, resolve them:
+git add <conflicted-files>
+git cherry-pick --continue
+
+# Push to rackerlabs fork
+git push rackerlabs understack/2026.1
+```
+
+### Example workflow for a specific PR
+
+Following the backporting workflow above results in a PR like https://github.com/rackerlabs/nova/pull/XXX:
+
+1. Find the commit hash from upstream master
+2. Cherry-pick it to the branch: `git cherry-pick <COMMIT_HASH>`
+3. Resolve any conflicts if needed
+4. Test the changes locally
+5. Push to the rackerlabs understack branch
+
+### Note on patch sources
+
+Patches can come from:
+- OpenStack upstream master branch (`openstack/nova` - origin/master)
+- Other branches or forks that have fixes needed