nmcli-cli-bridge-delete

#!/bin/bash
#
# nmcli-cli-bridge-delete
#
# Copyright (c) 2019-2026 Jun Futagawa (jfut)
#
# This software is released under the MIT License.
# http://opensource.org/licenses/mit-license.php

ECHO_OR_EXECUTE="echo"

print_command() {
    # Print the nmcli command in a reusable shell-quoted form.
    printf '%q' "$1"
    shift
    printf ' %q' "$@"
    printf '\n'
}

echo_or_execute() {
    local RET

    if [[ -z "${ECHO_OR_EXECUTE}" ]]; then
        printf 'Applying: '
        print_command "$@"
        "$@"
        RET=$?
        if [[ ${RET} -ne 0 ]]; then
            echo "Error: command failed (${RET})." >&2
            exit "${RET}"
        fi
    else
        print_command "$@"
    fi
}

usage() {
    cat << _EOF_
Usage:

    $0 [-n] [-x] BRIDGE_NAME

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

    Examples:
        $0 br1

_EOF_
}

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

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

bridge_delete() {
    local BRIDGE_NAME=${1:-}
    local CONNECTION_LIST
    local MASTER
    local RET
    local i

    # Find lower interface
    CONNECTION_LIST=$(nmcli -g NAME connection show)
    RET=$?
    if [[ ${RET} -ne 0 ]]; then
        echo "Error: failed to list connections (${RET})." >&2
        exit "${RET}"
    fi

    while IFS= read -r i
    do
        # Detach only slave profiles attached to the target bridge.
        [[ -z "${i}" ]] && continue
        MASTER=$(nmcli -g connection.master connection show "${i}")
        [[ "${MASTER}" != "${BRIDGE_NAME}" ]] && continue
        echo_or_execute nmcli connection modify "${i}" connection.master "" connection.slave-type ""
    done <<< "${CONNECTION_LIST}"

    # Delete bridge interface
    echo_or_execute nmcli connection delete "${BRIDGE_NAME}"
}

# 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

    bridge_delete "${@}"
}

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