cloud_aws_ebs_nvme_id

#!/usr/bin/env bash

# Copyright (c) 2018 The CoreOS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

usage() {
    echo "Usage: $0 [-d|-n|-h] <device>" 1>&2
}

# Get partition ID from device name, e.g. '/dev/nvme0n1p2' -> '1'
namespace_id() {
    check_udev_aws
    NSID=$(echo -n "$1" | cut -f 3 -d 'n' | cut -f 1 -d 'p')
    echo "_NS_ID=${NSID}"
}

# Get device name from raw metadata,
# see https://github.com/coreos/bugs/issues/2399.
devname() {
    check_udev_aws
    RAWVOL=$(nvme id-ctrl --raw-binary "$1" | cut -c3073-3104 | tr -s ' ' | sed 's/ $//g')
    VOL="${RAWVOL#/dev/}"
    if [[ -n "$VOL" ]]; then
        echo "${VOL}"
    else
        exit 1
    fi
}

# Ensure this is run with proper environment populated by udev,
# and acting on an AWS EBS device.
check_udev_aws() {
    if [ "${ID_MODEL}" != "Amazon Elastic Block Store" ]; then
        if [ "$(cut -d"_" -f1 <<<"${ID_SERIAL}")" != "Amazon Elastic Block Store" ]; then
            echo 'Stopping due to non-matching ID_MODEL or ID_SERIAL env variable'
            exit 1
        fi
    fi
}

while getopts "hd:n:" o; do
    case "${o}" in
        d)
            devname "${OPTARG}"
            exit 0
            ;;
        n)
            namespace_id "${OPTARG}"
            exit 0
            ;;
        h)
            usage
            exit 0
            ;;
        *)
            usage
            exit 1
            ;;
    esac
done