feat: add mios-overlay.sh and wire into Justfile targets

Author: mios-dev

Justfile

@@ -26,18 +26,18 @@ flight-status:
 
 # Unified initialization (Mode 2: User-space)
 init:
-    @chmod +x tools/mios-init.sh
-    @./tools/mios-init.sh user
+    @chmod +x tools/mios-overlay.sh
+    sudo ./tools/mios-overlay.sh
 
 # System-wide deployment (Mode 1: FHS system install)
 deploy:
-    @chmod +x tools/mios-init.sh
-    @./tools/mios-init.sh deploy
+    @chmod +x tools/mios-overlay.sh
+    sudo ./tools/mios-overlay.sh
 
 # Live ISO Initiation (Mode 0: Overlay onto root)
 live-init:
-    @chmod +x tools/mios-init.sh
-    @./tools/mios-init.sh live-init
+    @chmod +x tools/mios-overlay.sh
+    sudo ./tools/mios-overlay.sh
 
 # Build OCI image locally
 build: artifact preflight flight-status

tools/mios-overlay.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+# ============================================================================
+# mios-overlay.sh - System-wide FHS Overlay
+# ----------------------------------------------------------------------------
+# Overlays the local repository (usr/, etc/, var/) onto the system root.
+# This "MiOS-ifies" a running host or build-root.
+# ============================================================================
+set -euo pipefail
+
+# Colors for high-signal output
+BLUE="\033[1;34m"
+GREEN="\033[1;32m"
+YELLOW="\033[1;33m"
+RED="\033[1;31m"
+NC="\033[0m"
+
+log() { echo -e "${BLUE}[mios-overlay]${NC} $1"; }
+warn() { echo -e "${YELLOW}[warn]${NC} $1"; }
+error() { echo -e "${RED}[error]${NC} $1"; exit 1; }
+
+# --- Pre-flight ---
+[[ "$EUID" -eq 0 ]] || error "Must run as root/sudo"
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
+
+log "Starting overlay from: $REPO_ROOT"
+
+# --- 1. /usr (Infrastructure & Binaries) ---
+if [[ -d "usr" ]]; then
+    log "Overlaying /usr (excluding /usr/local)..."
+    tar -C "usr" -cf - --exclude="./local" . | tar -C /usr --no-overwrite-dir -xf -
+fi
+
+# --- 2. /usr/local (Custom Binaries / persistent write-through) ---
+if [[ -d "usr/local" ]]; then
+    log "Overlaying /usr/local..."
+    if [[ -L /usr/local ]]; then
+        TARGET="$(readlink -f /usr/local)"
+        log "  /usr/local is symlink -> $TARGET; writing through"
+        mkdir -p "$TARGET"
+        tar -C "usr/local" -cf - . | tar -C "$TARGET" --no-overwrite-dir -xf -
+    else
+        tar -C "usr/local" -cf - . | tar -C /usr/local --no-overwrite-dir -xf -
+    fi
+fi
+
+# --- 3. /etc (System Configuration) ---
+if [[ -d "etc" ]]; then
+    log "Overlaying /etc..."
+    tar -C "etc" -cf - . | tar -C /etc --no-overwrite-dir -xf -
+fi
+
+# --- 4. /var (System State & tmpfiles initialization) ---
+# Note: var in repo is usually empty or template-only. 
+# We rely on systemd-tmpfiles for actual directory creation.
+if [[ -d "var" ]] && [[ "$(ls -A var)" ]]; then
+    log "Overlaying /var..."
+    tar -C "var" -cf - . | tar -C /var --no-overwrite-dir -xf -
+fi
+
+# --- 5. /home -> /var/home (bootc-style alignment) ---
+if [[ -d "home" ]]; then
+    log "Overlaying /home templates to /var/home..."
+    mkdir -p /var/home
+    tar -C "home" -cf - . | tar -C /var/home --no-overwrite-dir -xf -
+    
+    if [[ ! -L /home ]]; then
+        warn "/home is not a symlink; expected /var/home for bootc parity."
+    fi
+fi
+
+# --- 6. Post-process ---
+log "Normalizing systemd unit permissions..."
+find /usr/lib/systemd -type f \( -name "*.service" -o -name "*.socket" -o -name "*.timer" \) -exec chmod 644 {} + 2>/dev/null || true
+
+log "Triggering systemd-tmpfiles to initialize /var..."
+systemd-tmpfiles --create --prefix=/var 2>/dev/null || true
+
+if command -v restorecon &>/dev/null; then
+    log "Relabeling SELinux contexts..."
+    restorecon -RF /usr /etc /var 2>/dev/null || true
+fi
+
+echo -e "\n${GREEN}━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}"
+echo -e "${GREEN}  ✅ MiOS Overlay Applied Successfully${NC}"
+echo -e "${GREEN}━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}\n"