#!/bin/sh
# 60-hostname.sh — Set system hostname
# If cloud-init (stage 45) already set the hostname, skip this stage.

# Cloud-init writes /etc/hostname and saves to data partition
if [ "$CLOUDINIT_APPLIED" = "1" ] && [ -f /etc/hostname ]; then
    HOSTNAME="$(cat /etc/hostname)"
    if [ -n "$HOSTNAME" ]; then
        log "Hostname already set by cloud-init: $HOSTNAME"
        return 0
    fi
fi

if [ -f "$DATA_MOUNT/etc-kubesolo/hostname" ]; then
    HOSTNAME="$(cat "$DATA_MOUNT/etc-kubesolo/hostname")"
elif [ -f /etc/kubesolo/hostname ]; then
    HOSTNAME="$(cat /etc/kubesolo/hostname)"
else
    # Generate hostname from MAC address of primary interface
    MAC_SUFFIX=""
    for iface in /sys/class/net/*; do
        iface="$(basename "$iface")"
        case "$iface" in lo|docker*|veth*|br*|cni*) continue ;; esac
        MAC_SUFFIX="$(cat "/sys/class/net/$iface/address" 2>/dev/null | tr -d ':' | tail -c 7)"
        break
    done
    HOSTNAME="kubesolo-${MAC_SUFFIX:-unknown}"
fi

hostname "$HOSTNAME"
echo "$HOSTNAME" > /etc/hostname
echo "127.0.0.1 $HOSTNAME" >> /etc/hosts

# Generate /etc/machine-id if missing (kubelet requires it)
if [ ! -f /etc/machine-id ]; then
    if [ -f "$DATA_MOUNT/etc-kubesolo/machine-id" ]; then
        cp "$DATA_MOUNT/etc-kubesolo/machine-id" /etc/machine-id
    else
        # Generate from hostname hash (deterministic across reboots)
        printf '%s' "$HOSTNAME" | md5sum 2>/dev/null | cut -d' ' -f1 > /etc/machine-id || \
            cat /proc/sys/kernel/random/uuid 2>/dev/null | tr -d '-' > /etc/machine-id || true
        # Persist for next boot
        cp /etc/machine-id "$DATA_MOUNT/etc-kubesolo/machine-id" 2>/dev/null || true
    fi
fi

log_ok "Hostname set to: $HOSTNAME"