install: Add --preserve-var and --merge-etc to to-existing-root

.packit.yaml

@@ -102,6 +102,27 @@ jobs:
             context:
               running_env: "packit"
 
+  # This plan uses an image-mode harness plus a separate package-mode target.
+  - job: tests
+    trigger: pull_request
+    identifier: package-mode-tier-1
+    require:
+      label:
+        present:
+          - ci/tier-1
+    targets:
+      - centos-stream-10-x86_64
+      - centos-stream-10-aarch64
+      - fedora-latest-stable-x86_64
+      - fedora-latest-stable-aarch64
+    tmt_plan: /tmt/plans/package-mode
+    tf_extra_params:
+      environments:
+        - tmt:
+            context:
+              running_env: "packit"
+              package_source: "artifacts"
+
   # ci/merge: full target set
   - job: tests
     trigger: pull_request
@@ -124,6 +145,28 @@ jobs:
             context:
               running_env: "packit"
 
+  - job: tests
+    trigger: pull_request
+    identifier: package-mode-full
+    require:
+      label:
+        present:
+          - ci/merge
+    targets:
+      - centos-stream-9-x86_64
+      - centos-stream-9-aarch64
+      - centos-stream-10-x86_64
+      - centos-stream-10-aarch64
+      - fedora-all-x86_64
+      - fedora-all-aarch64
+    tmt_plan: /tmt/plans/package-mode
+    tf_extra_params:
+      environments:
+        - tmt:
+            context:
+              running_env: "packit"
+              package_source: "artifacts"
+
   - job: propose_downstream
     trigger: release
     dist_git_branches:

CONTRIBUTING.md

@@ -88,6 +88,73 @@ To run a specific test:
 just test-tmt readonly
 ```
 
+The package-mode tests use a separate TMT plan with two disposable VMs. By
+default, `just test-tmt-package-mode` builds `localhost/bootc` from the latest
+Fedora bootc base and uses TMT's `fedora` image alias (the latest released
+Fedora image). This performs a full local image build, so it takes longer and
+uses more disk/network than simply launching the VM test. The build archive is
+stored under the ignored `target/` directory and copied to the harness VM.
+For local Just runs, TMT uses a temporary metadata root containing only
+`.fmf/` and `tmt/`, so ignored build output is not synchronized to either VM;
+the OCI archive stays in `target/` and is synchronized separately.
+TMT's run workdir defaults to
+`${XDG_CACHE_HOME:-$HOME/.cache}/bootc/tmt-package-mode-runs`. It must be outside
+the checkout and temporary metadata root, and visible at the same absolute path
+to both the TMT container and the host session-libvirt process so libvirt can
+access seed images created by TMT. Set `TMT_WORKDIR_ROOT` to use a different
+shared directory that meets these requirements:
+
+```bash
+TMT_WORKDIR_ROOT=/shared/tmt-package-mode-runs just test-tmt-package-mode
+```
+
+The target creates the directory if needed and passes its absolute path to TMT.
+To use a different guest image, set `test_disk_image`:
+
+```bash
+# Uses the latest released Fedora image.
+just test-tmt-package-mode
+
+# Optional: use another TMT-compatible image.
+test_disk_image=/path/to/package-mode-test-image.qcow2 just test-tmt-package-mode
+```
+
+The local build base can be overridden with `BOOTC_base`; when changing the
+guest image, choose a matching bootc base (for example, Fedora guests should use
+the corresponding `quay.io/fedora/fedora-bootc` release). The package-mode test
+performs a destructive migration inside its target VM, so use only a disposable
+image/environment. TMT and its virtual provisioning backend must be installed
+and configured locally.
+
+Packit runs the same plan with `package_source=artifacts`: the TMT controller
+must provide `/var/share/test-artifacts/` with exactly one top-level `.src.rpm`
+and `/etc/yum.repos.d/test-artifacts.repo`. `/var/ARTIFACTS/` is forwarded to
+the harness when present, but is an optional Testing Farm pass-through, not a
+test prerequisite. Local `just test-tmt-package-mode` runs use
+`package_source=local` and need none of those controller artifact paths; they
+skip Packit provisioning and the harness reboot while retaining the shared
+migration test and archive transfer. Local mode tests migration behavior using
+the image built from the checkout; it does not validate the SRPM, repository, or
+Packit provisioning path.
+
+In both package-source modes, the target preloads the test's bound container
+images because the installer resolves those references from target-side storage.
+
+Package-mode OCI archives and artifact directories are transferred from the
+harness with `ansible.posix.synchronize` (rsync over TMT's forwarded SSH
+connection). This avoids Ansible `fetch`/`copy` falling back to a piped SSH
+transfer that can buffer a 1 GB+ archive in controller memory; the original
+SFTP/SCP errors were not recorded. The TMT controller must have `rsync` and the
+`ansible.posix` collection installed. TMT 1.79 or newer is required on both the
+local and Testing Farm controllers. The plan installs `rsync` on both guests
+from their configured base repositories before synchronizing any payloads.
+The verified archive and its SHA256 sidecar are staged under the run-specific
+controller `TMT_PLAN_DATA/package-mode-transfer` directory. TMT 1.79 pushes
+controller plan data to the selected test guest before execute, where the test
+checks the sidecar and loads the archive. A finish playbook removes controller
+staging after test success or failure; the fetch playbook still cleans up if
+staging or checksum verification fails during prepare.
+
 ### Faster iteration cycles
 
 The test cycle currently builds a disk image and creates a new ephemeral

Justfile

@@ -48,7 +48,17 @@ erofs_version := env("BOOTC_erofs_version", "v1")
 # Baseconfigs to inject into the image for testing (e.g. "etc-transient" or "root-transient")
 baseconfigs := env("BOOTC_baseconfigs", "")
 # Base container image to build from
-base := env("BOOTC_base", "quay.io/centos-bootc/centos-bootc:stream10")
+default_base := "quay.io/centos-bootc/centos-bootc:stream10"
+base := env("BOOTC_base", default_base)
+# Package-mode tests default to Fedora to match test_disk_image=fedora.
+# Honor BOOTC_base or a Justfile `base=` override when explicitly provided.
+package_mode_base := if base != default_base {
+    base
+} else if env("BOOTC_base", "") != "" {
+    base
+} else {
+    "quay.io/fedora/fedora-bootc:latest"
+}
 # Buildroot base image
 buildroot_base := env("BOOTC_buildroot_base", "quay.io/centos/centos:stream10")
 # Optional: path to extra source (e.g. composefs-rs) for local development
@@ -192,6 +202,42 @@ test-tmt *ARGS: build
     @just _build-upgrade-image
     @just test-tmt-nobuild {{ARGS}}
 
+# Run the package-mode TMT plan using its two TMT-provisioned guests.
+[group('core')]
+test-tmt-package-mode:
+    #!/bin/bash
+    set -euo pipefail
+    repo_root="$(git rev-parse --show-toplevel)"
+    repo_root="$(realpath -- "$repo_root")"
+    metadata_root="$(realpath -- "$(mktemp -d "${TMPDIR:-/tmp}/bootc-tmt-package-mode.XXXXXXXX")")"
+    trap 'rm -rf -- "$metadata_root"' EXIT
+    cp -a -- "$repo_root/.fmf" "$metadata_root/"
+    cp -a -- "$repo_root/tmt" "$metadata_root/"
+    workdir_root="${TMT_WORKDIR_ROOT:-${XDG_CACHE_HOME:-$HOME/.cache}/bootc/tmt-package-mode-runs}"
+    workdir_root="$(realpath -m -- "$workdir_root")"
+    if [[ "$workdir_root" == "$repo_root" || "$workdir_root" == "$repo_root/"* ]]; then
+        echo "TMT workdir root must be outside the checkout (fmf root): $workdir_root" >&2
+        exit 1
+    fi
+    if [[ "$workdir_root" == "$metadata_root" || "$workdir_root" == "$metadata_root/"* ]]; then
+        echo "TMT workdir root must be outside the temporary metadata root: $workdir_root" >&2
+        exit 1
+    fi
+    mkdir -p -- "$workdir_root"
+    just base={{package_mode_base}} build
+    if [[ "{{base_img}}" != localhost/bootc ]]; then
+        podman tag {{base_img}} localhost/bootc
+    fi
+    podman save --format oci-archive \
+        --output target/package-mode-local.oci localhost/bootc
+    archive_path="$(realpath -- target/package-mode-local.oci)"
+    PACKAGE_MODE_IMAGE_ARCHIVE="$archive_path" tmt \
+        --root "$metadata_root" \
+        --context=running_env=packit \
+        --context=package_source=local \
+        --context="test_disk_image=${test_disk_image:-fedora}" \
+        run --workdir-root "$workdir_root" plans --name '^/tmt/plans/package-mode$'
+
 # Split out from `test-container` because, unlike the container integration tests,
 # unit tests don't depend on variant/filesystem/bootloader/boot_type/seal_state, so
 # CI runs this once per OS (in the `package` job) instead of once per test-integration