feat: add dedicated AMI build script

Replaces fragile 'head -n -12' line-stripping of the prerequisites
script with a self-contained build script that:
- Installs Docker, wireguard, lsof, iptables
- Sets up /etc/rc.local for first-boot DAppNode installation
- Skips network connectivity checks (not needed during AMI build)
- Handles Ubuntu 24 LTS properly

Author: 3alpha

scripts/dappnode_ami_build.sh

@@ -0,0 +1,118 @@
+#!/bin/bash
+# DAppNode AMI Build Script
+# Purpose: Install prerequisites and set up first-boot installer for EC2 Image Builder.
+# This script is self-contained and does NOT depend on line-counting hacks
+# against the upstream prerequisites script (which changes over time).
+
+set -euo pipefail
+
+DAPPNODE_DIR="/usr/src/dappnode"
+LOGS_DIR="$DAPPNODE_DIR/logs"
+LOG_FILE="$LOGS_DIR/ami_build.log"
+
+mkdir -p "$DAPPNODE_DIR/scripts" "$LOGS_DIR"
+touch "$LOG_FILE"
+
+log() { echo "[AMI-BUILD] $*" | tee -a "$LOG_FILE"; }
+
+lsb_dist="$(. /etc/os-release && echo "$ID")"
+log "Detected OS: $lsb_dist"
+
+# ─── Docker ───────────────────────────────────────────────────────────────────
+install_docker() {
+    log "Installing Docker..."
+    apt-get update -y
+    apt-get remove -y docker docker-engine docker.io containerd runc || true
+
+    apt-get install -y ca-certificates curl lsb-release
+    install -m 0755 -d /etc/apt/keyrings
+    curl -fsSL "https://download.docker.com/linux/${lsb_dist}/gpg" -o /etc/apt/keyrings/docker.asc
+    chmod a+r /etc/apt/keyrings/docker.asc
+
+    echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/$lsb_dist $(lsb_release -cs) stable" \
+        | tee /etc/apt/sources.list.d/docker.list >/dev/null
+
+    apt-get update -y
+    apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
+    [ -f "/usr/bin/xz" ] || apt-get install -y xz-utils
+    log "Docker installed successfully"
+}
+
+# ─── Docker Compose alias (legacy compatibility) ──────────────────────────────
+install_compose_alias() {
+    cat >/usr/local/bin/docker-compose <<'EOL'
+#!/bin/bash
+docker compose "$@"
+EOL
+    chmod +x /usr/local/bin/docker-compose
+}
+
+# ─── Wireguard ────────────────────────────────────────────────────────────────
+install_wireguard() {
+    log "Installing wireguard..."
+    apt-get update -y
+    apt-get install -y wireguard-dkms || apt-get install -y wireguard-tools || true
+    if modprobe wireguard >/dev/null 2>&1; then
+        log "Wireguard module loaded"
+    else
+        log "WARNING: wireguard kernel module not available (may be built-in on this kernel)"
+    fi
+}
+
+# ─── Lsof ─────────────────────────────────────────────────────────────────────
+install_lsof() {
+    log "Installing lsof..."
+    apt-get install -y lsof
+}
+
+# ─── Iptables ─────────────────────────────────────────────────────────────────
+install_iptables() {
+    log "Installing iptables..."
+    apt-get install -y iptables
+}
+
+# ─── Main prerequisites installation ─────────────────────────────────────────
+log "=== Starting DAppNode AMI prerequisites ==="
+
+apt-get update -y | tee -a "$LOG_FILE"
+
+if ! docker -v >/dev/null 2>&1; then
+    install_docker 2>&1 | tee -a "$LOG_FILE"
+else
+    log "Docker already installed"
+fi
+
+install_compose_alias
+
+if ! modprobe wireguard >/dev/null 2>&1; then
+    install_wireguard 2>&1 | tee -a "$LOG_FILE"
+else
+    log "Wireguard already available"
+fi
+
+if ! lsof -v >/dev/null 2>&1; then
+    install_lsof 2>&1 | tee -a "$LOG_FILE"
+else
+    log "lsof already installed"
+fi
+
+if ! iptables -V >/dev/null 2>&1; then
+    install_iptables 2>&1 | tee -a "$LOG_FILE"
+else
+    log "iptables already installed"
+fi
+
+# ─── Set up first-boot installer ─────────────────────────────────────────────
+log "=== Setting up first-boot installer ==="
+
+wget -O "$DAPPNODE_DIR/scripts/dappnode_install.sh" https://installer.dappnode.io
+chmod +x "$DAPPNODE_DIR/scripts/dappnode_install.sh"
+
+cat > /etc/rc.local << 'RC'
+#!/bin/sh -e
+/usr/src/dappnode/scripts/dappnode_install.sh
+exit 0
+RC
+chmod +x /etc/rc.local
+
+log "=== AMI build complete ==="