Retrive Docker container network veth pair device on host machine

docker-veth.sh

#!/bin/bash

set -o errexit
set -o nounset
set -o pipefail
# set -o noclobber
# set -o xtrace

cd -- "$(dirname "$0")"

container_id=$1
net_ns=$(docker inspect --format='{{.NetworkSettings.SandboxKey}}' "$container_id")
peer_ifindex=$(nsenter --net="$net_ns" -- ethtool -S eth0 | grep -Po '(?<=peer_ifindex:\s)\d+')
ip link | grep -A1 "^$peer_ifindex:"