Linux Repo Sync

Repo Sync — safe git updates on a server

Distro support

Fully portable. This skill is git-only and identical on both families (Debian/Ubuntu and the RHEL family: Fedora, RHEL, CentOS Stream, Rocky, Alma, Oracle). The doctrine below — pull --rebase --autostash, porcelain dirty-checks, never reset --hard/clean -fd — is distro-neutral. The only difference is installing git itself.

In sk-* scripts use pkg_install git from common.sh if you must ensure git is present. See docs/multi-distro/plan.md.

Use when

• Writing, reviewing, or running any script that pulls git repos on a server (a repo-update menu, a deploy hook, a cron sync).
• Updating one or many repos on a managed host as part of deployment or routine maintenance.
• Deciding how an automated update should treat local, uncommitted, or untracked changes in a server-side working tree.

Do not use when

• The task is a one-off git pull a developer runs by hand in their own checkout and watches the output of.
• The task is authoring the generic script scaffold rather than the git behaviour; for the script contract load linux-bash-scripting first, then apply this doctrine to the git steps.

Required Inputs

Capability Contract

Read/search status and fetch inspection may be read-only. Pull/rebase changes the working tree and needs explicit authority. Never delete, reset, auto-resolve, force-push, expose credentials, or run an unapproved post-pull command.

Degraded Mode

If network, credentials, Git, upstream tracking, or a clean conflict state is unavailable, preserve the tree and report branch, status, and the failed step. Do not call a fetched or conflicted repository updated.

Decision Rules

Workflow

1. Confirm the path is a git working tree (<path>/.git exists).
2. Check the working tree state with git status --porcelain before touching it.
3. Pull with git pull --rebase --autostash so local work is stashed, the rebase runs, and the work is re-applied on top.
4. On conflict, stop and tell the operator how to recover — never discard.
5. Leave untracked files in place, always.
6. Run any post-pull build only after a clean, successful update.

Quality standards

• An update must never destroy uncommitted or untracked work.
• A dirty working tree is reported to the operator, never silently wiped.
• A failed rebase or stash re-apply leaves the operator a clear recovery path.
• The same script is safe to run twice (idempotent) and safe to run on a repo someone edited five minutes ago.

Anti-patterns

• git reset --hard HEAD in automation. Fix: preserve local work with rebase/autostash and stop on conflict.
• git clean -fd or -fdx. Fix: leave untracked files untouched and report collisions.
• Resetting local changes as a routine pre-pull step. Fix: inventory and preserve the dirty state.
• Auto-resolving or auto-aborting a rebase/stash conflict. Fix: leave state intact for the owner.
• Removing uploads, .env, or generated config to avoid conflicts. Fix: stop and report the conflicting path.

Outputs

Evidence Produced

Capability Recovery

On conflict, leave Git's state intact and show git status, git rebase --continue, git rebase --abort, and git stash list. Never choose the recovery path for the owner.

Worked Example

A production checkout has a modified tracked config and an untracked upload. Report both, run the authorised git pull --rebase --autostash, leave the upload untouched, and record commit IDs. If the autostash conflicts, stop before the build and hand the exact recovery state to the owner.

References

• ../../docs/continuous-improvement/safe-reversible-operations-standard.md

• ../../docs/continuous-improvement/value-stream-5s-qc-story.md

• references/safe-update-pattern.md

The doctrine (binding on every repo-update script)

This is a STANDARD, not a suggestion. It exists because a repo-update menu script once ran git reset --hard HEAD + git clean -fd before pulling and silently wiped a developer's uncommitted edits. That must never be possible again on any server we manage.

1. NEVER use git reset --hard in an automated or menu repo-update script. It destroys uncommitted changes to tracked files with no undo.
2. NEVER use git clean -fd (or -fdx) in an automated or menu repo-update script. It deletes untracked files — uploads, .env, generated config — that git is not tracking precisely because they must survive.
3. Prefer git pull --rebase --autostash. --autostash stashes any local changes before the rebase and re-applies them afterwards, so local work is preserved through the update. This is the default pull command for every server-side update.
4. Detect a dirty working tree before pulling with git status --porcelain. If it is non-empty, warn the operator that local changes exist (and will be stashed and re-applied, not discarded). Never discard them.
5. On a rebase or stash-reapply conflict, STOP. Do not auto-resolve, do not auto-abort. Report the conflict and the recovery options to the operator:
   • git rebase --continue after resolving the conflicting files, or
   • git rebase --abort to return to the pre-pull state, and
   • git stash list — the autostash is preserved here; recover it with git stash pop once the tree is clean.
6. Untracked files are left in place, always. An update never removes a file git is not tracking.

The safe pattern (copy-paste)

update_repo_safely() {
    local path="$1"

    [[ -d "$path/.git" ]] || { echo "not a git repo: $path" >&2; return 1; }
    cd "$path" || return 1

    # 1. Detect a dirty working tree — warn, never wipe.
    if [[ -n "$(git status --porcelain)" ]]; then
        echo "WARNING: $path has local changes."
        echo "         They will be stashed and re-applied, not discarded."
    fi

    # 2. Pull with rebase + autostash: local work is preserved.
    if git pull --rebase --autostash; then
        echo "updated: $(git rev-parse --abbrev-ref HEAD) -> $(git log -1 --oneline)"
    else
        # 3. Conflict — stop and hand the operator a recovery path.
        echo "ERROR: pull/rebase hit a conflict in $path." >&2
        echo "  Resolve the files, then:  git rebase --continue" >&2
        echo "  Or roll back the pull:     git rebase --abort"   >&2
        echo "  Your stashed local work:   git stash list  (recover with: git stash pop)" >&2
        return 1
    fi
}

What this never does: no git reset --hard, no git clean, no removal of untracked files, no automatic conflict resolution.

Canonical script on this server

/usr/local/bin/update-all-repos is the menu-driven repo-update tool that must exist on every managed server (see notes/update-all-repos-setup.md). It must follow this doctrine: a porcelain dirty-check plus git pull --rebase --autostash, never git reset --hard + git clean -fd. The sk-update-all-repos script (linux-site-deployment) is the engine version of the same tool and is held to the same standard.

If you find any repo-update script on a server still doing git reset --hard or git clean -fd, that is a bug to fix, not a pattern to copy.

Scripts

This skill installs the following scripts to /usr/local/bin/. To install:

sudo install-skills-bin linux-repo-sync

Verify

# A repo-update script is safe iff this returns nothing:
grep -nE 'git[[:space:]]+reset[[:space:]]+--hard|git[[:space:]]+clean[[:space:]]+-fd' /usr/local/bin/update-all-repos

# And iff it pulls with autostash:
grep -n 'pull --rebase --autostash' /usr/local/bin/update-all-repos