Architecture

Project Layout

src/
  config/   models.rs, uci_key.rs, validation.rs
  compile/  generator.rs, pipeline.rs, secrets.rs
  target/   deploy.rs, diff.rs
  utils/    error.rs, helpers.rs

Single compilation seam: compile::pipeline::compile_config.

UCI Idempotency Strategy

Named Section (network.lan): Wiped via uci delete, rebuilt via uci set. Removed Nix options are deleted on target.
Anonymous List (wireless.@wifi-iface[0]): Wiped via while uci -q delete config.@type[0]; do :; done, re-added sequentially.
Array Diff: Joined via \u{1f} (Unit Separator) control character, making element reordering diff-neutral.
Libuci Protection: Automatically emits touch /etc/config/<cfg> before uci batch to avoid silent file creation failures.

Anti-Brick Rollback System

Layer	Trigger	Action
Layer A (In-Session)	Network loss / SSH timeout	Background watchdog (`trap '' HUP; sleep 60`). Killed on SSH handshake success.
Layer B (Boot-Time)	Power loss / Reboot mid-deploy	Init script `S15nuci_rollback` restores `/etc/config` from `/etc/.uci-rollback-backup` on boot, then self-deletes.

Async Detached Reload

Avoids SSH exit status 255 (TCP Reset on interface/sshd restart) by running reloads in a background subshell:

( sleep 1; <reload_commands> ) >/dev/null 2>&1 &

The script exits 0 immediately, closing SSH cleanly before services restart.

Target Execution Requirements

Text Files: POSIX cat > path <<'NUCI_FILE_{i}_EOF' (quoted delimiter prevents shell expansion, zero base64 dependency).
Binary Files: Base64 decoded via echo '<b64>' | base64 -d > path.
Root Password: chpasswd <<'CHPWD' or passwd fallback (POSIX heredoc).
Local Packages: Streamed via pure Rust tar::Builder into target /tmp/ without host disk files.