#!/usr/bin/env bash
# 在 Linux 容器内执行：对指定网卡注入丢包。用法：apply-loss.sh <iface> <loss_percent>
set -euo pipefail

IFACE="${1:-eth0}"
LOSS="${2:-20}"

if ! command -v tc >/dev/null 2>&1; then
  echo "tc not found; use an image with iproute2 (e.g. nicolaka/netshoot)" >&2
  exit 1
fi

tc qdisc replace dev "$IFACE" root netem loss "${LOSS}%"
echo "netem: iface=${IFACE} loss=${LOSS}%"
tc qdisc show dev "$IFACE"