nmcli-cli-ipv4

#!/bin/bash
#
# nmcli-cli-ipv4
#
# Copyright (c) 2019 Jun Futagawa (jfut)
#
# This software is released under the MIT License.
# http://opensource.org/licenses/mit-license.php

ECHO_OR_EXECUTE="echo"

echo_or_execute() {
    if [[ -z "${ECHO_OR_EXECUTE}" ]]; then
        echo "Applying: ${@}"
        eval ${@}
    else
        ${ECHO_OR_EXECUTE} ${@}
    fi
}

usage() {
    cat << _EOF_
Usage:

    $0 [-n] [-x] NAME dhcp|static|disable IP_SUBNET [GATEWAY] [DNS]

    Options:
        -n No interface check (Default: check interface)
        -x Run command (Default: echo only)

    Examples:
        $0 eno1 dhcp
        $0 eno1 static 192.168.1.101/24 192.168.1.1 "192.168.1.1,10.0.0.2"
        $0 eno1 static 192.168.1.101/24
        $0 eno1 disable

_EOF_
}

check() {
    local IF_NAME=${1:-}

    # Check interface
    nmcli connection show "${IF_NAME}" > /dev/null 2>&1
    RET=$?
    if [[ ${RET} -ne 0 ]]; then
        echo "Error: Target interface \"${IF_NAME}\" not found."
        exit 1
    fi
}

ipv4_set_dhcp() {
    local IF_NAME=${1:-}

    # DNS
    echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.dns \"\"

    # Gateway
    echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.gateway \"\"

    # IP
    echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.addresses \"\" ipv4.method auto
}

ipv4_set_static() {
    local IF_NAME=${1:-}
    local IF_IP_SUBNET=${2:-}
    local IF_GATEWAY=${3:-}
    local IF_DNS=${4:-}

    # IP
    echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.addresses \"${IF_IP_SUBNET}\" ipv4.method manual

    # Option: Gateway
    if [[ ! -z "${IF_GATEWAY}" ]]; then
        echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.gateway \"${IF_GATEWAY}\"
    fi

    # Option: DNS
    if [[ ! -z "${IF_DNS}" ]]; then
        echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.dns \"${IF_DNS}\"
    fi
}

ipv4_set_disable() {
    local IF_NAME=${1:-}

    # DNS
    echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.dns \"\"

    # Gateway
    echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.gateway \"\"

    # IP
    echo_or_execute nmcli connection modify \"${IF_NAME}\" ipv4.addresses \"${IF_IP_SUBNET}\" ipv4.method disabled ipv6.method ignore
}

ipv4_set() {
    IF_NAME=${1:-}
    IF_METHOD=${2:-}
    IF_IP_SUBNET=${3:-}
    IF_GATEWAY=${4:-}
    IF_DNS=${5:-}

    if [[ "${IF_METHOD}" = "dhcp" ]]; then
        ipv4_set_dhcp "${IF_NAME}"
    elif [[ "${IF_METHOD}" = "static" ]]; then
        ipv4_set_static "${IF_NAME}" "${IF_IP_SUBNET}" "${IF_GATEWAY}" "${IF_DNS}"
    elif [[ "${IF_METHOD}" = "disable" ]]; then
        ipv4_set_disable "${IF_NAME}"
    else
        echo "Error: method \"${IF_METHOD}\" is invalid. (dhcp|static|disable) are supported."
        exit 1
    fi

    cat << _EOF_

# Next steps:
# -> Restart the interface:
#    nmcli-cli-restart "${IF_NAME}"
#
# -> Create a bond interface:
#    nmcli-cli-bond-add bond1 mode=... "${IF_NAME}" "ens2f0"
# -> Create a vlan interface:
#    nmcli-cli-vlan-add "${IF_NAME}.100" 100 "${IF_NAME}"
# -> Create a bridge interface:
#    nmcli-cli-bridge-add br1 "${IF_NAME}"
_EOF_
}

# Main
main() {
    local NO_CHECK="no"
    while getopts nxh OPT; do
        case "${OPT}" in
            "n" )
                NO_CHECK="yes" ;;
            "x" )
                ECHO_OR_EXECUTE="" ;;
            "h" )
                usage
                exit 0
                ;;
            * )
                usage
                exit 1
                ;;
        esac
    done
    shift $((OPTIND - 1))

    [[ $# -lt 1 ]] && usage && exit 1

    if [[ "${NO_CHECK}" = "no" ]]; then
        check "${@}"
    fi

    if [[ "${ECHO_OR_EXECUTE}" = "echo" ]]; then
        echo "# ${ECHO_OR_EXECUTE} only."
    fi

    ipv4_set "${@}"
}

[[ ${#BASH_SOURCE[@]} = 1 ]] && main "${@}"