# vigil

## Philosophy

- Never drop into an emergency shell for non-critical failures (e.g. non-root filesystem mount failure).
- Failures should be logged, not fatal.
- Configuration via declarative TOML unit files. _(just like in systemd, but without the extra bloatware. Objectively, it is convenient to write services for systemd)_

## Non-goals (explicitly out of scope)

- Socket or bus activation (also like systemd).
- Built-in cgroups, namespaces, or resource control.
- D-Bus integration.
- Dynamic dependency resolution beyond static unit deps.

## Implementation Roadmap

### Early system setup

- [x] Mount essential filesystems (`/proc`, `/sys`, `/dev` via `devtmpfs`).
- [ ] Spawn `udev` (or compatible device manager) as child process.
- [x] Mount user-defined filesystems from `/etc/fstab` (non-fatal on failure = log & continue).
- [ ] Activate `swap` (non-fatal on failure).
- [ ] Set hostname, timezone, and locale from config.
- [ ] Load kernel modules (via `modprobe` or direct `init_module` syscall).

### Core runtime responsibilities

- [ ] **Service management**
  - Parse TOML unit files (`/etc/vigil/units/*.toml`)
  - Start/stop/restart/status via `vigilctl`
  - Handle `Wants=`, `After=`, `Before=` dependencies
  - Auto-restart failed services (configurable: `restart = always|on-failure|never`)
- [ ] **Child process reaping**
  - Install `SIGCHLD` handler
  - Call `waitpid(-1, ...)` in loop to reap zombies
  - Log exit status, signal, and runtime duration per service
- [ ] **TTY & login**
  - Launch `getty` on configured TTYs (e.g. `tty1`–`tty6`)
  - Support custom `getty` paths/args per TTY in config

### System lifecycle control

- [ ] Handle `reboot`, `halt`, `poweroff` via `vigilctl`
- [ ] Properly terminate all services in reverse dependency order
- [ ] Sync filesystems and unmount (best-effort)
- [ ] Invoke `reboot(2)` / `halt(2)` syscalls directly

### Signal handling

- [ ] `SIGINT` / `SIGTERM` = graceful shutdown
- [ ] `SIGUSR1` / `SIGUSR2` = reload config or trigger debug dump
- [ ] Block all non-fatal signals during critical sections (e.g. mount)