install: Add --preserve-var and --merge-etc to to-existing-root - #2384
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install: Add --preserve-var and --merge-etc to to-existing-root#2384ckyrouac wants to merge 2 commits into
ckyrouac wants to merge 2 commits into
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Two robustness fixes surfaced while exercising the 3-way merge against real package-mode `/etc` trees (see the upcoming `--merge-etc` install flag): - In merge_leaf(), when copying a modified file into the new /etc, skip (with a warning) rather than fail when the cap-std copy hits "a path led outside of the filesystem". This happens when a path component in the current /etc leads through an absolute symlink that escapes the cap-std root (e.g. /etc/alternatives symlinks); the image's existing content wins for that path instead of aborting the whole merge. Clarify the comment on the analogous lstat-based removed-path check for consistency. - Warn and skip, instead of bailing, when a modified host file/symlink newly defaults to a directory in the target image (e.g. /etc/ssl/certs is a symlink in Fedora package mode but a directory in the bootc base image). The image's directory wins and the host's customization is dropped for that path. Update the file-to-directory unit test to match the new behavior. Assisted-by: AI
Add two flags to `bootc install to-existing-root` that are most useful
when migrating a package-mode system to a bootc image built externally:
--preserve-var Copy the running system's /var data into the new
deployment, and write a package-mode GRUB rollback
boot entry.
--merge-etc Apply the running system's /etc customisations onto
the new deployment via a 3-way merge.
Typical usage:
podman run --rm --privileged --pid=host --user=root:root \
-v /dev:/dev --security-opt label=type:unconfined_t \
-v /:/target -v /var/lib/containers:/var/lib/containers \
<fleet-image> \
bootc install to-existing-root \
--preserve-var \
--merge-etc \
--acknowledge-destructive
The implementation lives in the new `install/migrate` module; see its
module-level docs for the on-disk layout and the /var and /etc
migration strategies (reflink copy vs. plain copy, the pkgmode-rollback
BLS entry, and the etc-merge 3-way merge). install_to_existing_root()
extracts the two flags before opts is consumed, stashes the running
kernel/initramfs ahead of install_to_filesystem() when --preserve-var
is set (since that wipes /boot), and runs the post-install migration
steps afterward.
migrate.rs includes unit tests covering the pkgmode-rollback path
layout and the new /var path derivation from the deployment dir.
Assisted-by: AI
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This is AI generated with lots of guidance.
Add two flags to
bootc install to-existing-rootthat are most usefulwhen migrating a package-mode system to a bootc image built externally:
--preserve-var Copy the running system's /var data into the new
deployment, and write a package-mode GRUB rollback
boot entry.
--merge-etc Apply the running system's /etc customisations onto
the new deployment via a 3-way merge.
Typical usage:
podman run --rm --privileged --pid=host --user=root:root
-v /dev:/dev --security-opt label=type:unconfined_t
-v /:/target -v /var/lib/containers:/var/lib/containers
bootc install to-existing-root
--preserve-var
--merge-etc
--acknowledge-destructive