New upstream version 0.17.0+dfsg1

1 files changed, 1519 insertions, 0 deletions

diff --git a/utils/lib.sh b/utils/lib.sh
new file mode 100755
index 0000000..922227a
--- /dev/null
+++ b/utils/lib.sh
@@ -0,0 +1,1519 @@
+#!/usr/bin/env bash
+# -*- coding: utf-8; mode: sh indent-tabs-mode: nil -*-
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# shellcheck disable=SC2059,SC1117
+
+# ubuntu, debian, arch, fedora ...
+DIST_ID=$(source /etc/os-release; echo "$ID");
+# shellcheck disable=SC2034
+DIST_VERS=$(source /etc/os-release; echo "$VERSION_ID");
+
+ADMIN_NAME="${ADMIN_NAME:-$(git config user.name)}"
+ADMIN_NAME="${ADMIN_NAME:-$USER}"
+
+ADMIN_EMAIL="${ADMIN_EMAIL:-$(git config user.email)}"
+ADMIN_EMAIL="${ADMIN_EMAIL:-$USER@$(hostname)}"
+
+if [[ -z "${REPO_ROOT}" ]]; then
+    REPO_ROOT=$(dirname "${BASH_SOURCE[0]}")
+    while [ -h "${REPO_ROOT}" ] ; do
+        REPO_ROOT=$(readlink "${REPO_ROOT}")
+    done
+    REPO_ROOT=$(cd "${REPO_ROOT}/.." && pwd -P )
+fi
+
+if [[ -z ${TEMPLATES} ]]; then
+    TEMPLATES="${REPO_ROOT}/utils/templates"
+fi
+
+if [[ -z "$CACHE" ]]; then
+    CACHE="${REPO_ROOT}/cache"
+fi
+
+if [[ -z ${DIFF_CMD} ]]; then
+    DIFF_CMD="diff -u"
+    if command -v colordiff >/dev/null;  then
+        DIFF_CMD="colordiff -u"
+    fi
+fi
+
+DOT_CONFIG="${DOT_CONFIG:-${REPO_ROOT}/.config.sh}"
+
+source_dot_config() {
+    if [[ ! -e "${DOT_CONFIG}" ]]; then
+        err_msg "configuration does not extsts at: ${DOT_CONFIG}"
+        return 42
+    fi
+    # shellcheck disable=SC1090
+    source "${DOT_CONFIG}"
+}
+
+sudo_or_exit() {
+    # usage: sudo_or_exit
+
+    if [ ! "$(id -u)" -eq 0 ];  then
+        err_msg "this command requires root (sudo) privilege!" >&2
+        exit 42
+    fi
+}
+
+required_commands() {
+
+    # usage:  required_commands [cmd1 ...]
+
+    local exit_val=0
+    while [ -n "$1" ]; do
+
+        if ! command -v "$1" &>/dev/null; then
+            err_msg "missing command $1"
+            exit_val=42
+        fi
+        shift
+    done
+    return $exit_val
+}
+
+# colors
+# ------
+
+# shellcheck disable=SC2034
+set_terminal_colors() {
+    _colors=8
+    _creset='\e[0m'  # reset all attributes
+
+    _Black='\e[0;30m'
+    _White='\e[1;37m'
+    _Red='\e[0;31m'
+    _Green='\e[0;32m'
+    _Yellow='\e[0;33m'
+    _Blue='\e[0;34m'
+    _Violet='\e[0;35m'
+    _Cyan='\e[0;36m'
+
+    _BBlack='\e[1;30m'
+    _BWhite='\e[1;37m'
+    _BRed='\e[1;31m'
+    _BGreen='\e[1;32m'
+    _BYellow='\e[1;33m'
+    _BBlue='\e[1;34m'
+    _BPurple='\e[1;35m'
+    _BCyan='\e[1;36m'
+}
+
+if [ ! -p /dev/stdout ]; then
+    set_terminal_colors
+fi
+
+# reST
+# ----
+
+if command -v fmt >/dev/null; then
+    export FMT="fmt -u"
+else
+    export FMT="cat"
+fi
+
+rst_title() {
+    # usage: rst_title <header-text> [part|chapter|section]
+
+    case ${2-chapter} in
+        part)     printf "\n${_BGreen}${1//?/=}${_creset}\n${_BCyan}${1}${_creset}\n${_BGreen}${1//?/=}${_creset}\n";;
+        chapter)  printf "\n${_BCyan}${1}${_creset}\n${_BGreen}${1//?/=}${_creset}\n";;
+        section)  printf "\n${_BCyan}${1}${_creset}\n${_BGreen}${1//?/-}${_creset}\n";;
+        *)
+            err_msg "invalid argument '${2}' in line $(caller)"
+            return 42
+            ;;
+    esac
+}
+
+rst_para() {
+    # usage:  RST_INDENT=1 rst_para "lorem ipsum ..."
+    local prefix=''
+    if [[ -n $RST_INDENT ]] && [[ $RST_INDENT -gt 0 ]]; then
+        prefix="$(for i in $(seq 1 "$RST_INDENT"); do printf "  "; done)"
+        echo -en "\n$*\n" | $FMT | prefix_stdout "$prefix"
+    else
+        echo -en "\n$*\n" | $FMT
+    fi
+}
+
+die() {
+    echo -e "${_BRed}ERROR:${_creset} ${BASH_SOURCE[1]}: line ${BASH_LINENO[0]}: ${2-died ${1-1}}" >&2;
+    exit "${1-1}"
+}
+
+die_caller() {
+    echo -e "${_BRed}ERROR:${_creset} ${BASH_SOURCE[2]}: line ${BASH_LINENO[1]}: ${FUNCNAME[1]}(): ${2-died ${1-1}}" >&2;
+    exit "${1-1}"
+}
+
+err_msg()  { echo -e "${_BRed}ERROR:${_creset} $*" >&2; }
+warn_msg() { echo -e "${_BBlue}WARN:${_creset}  $*" >&2; }
+info_msg() { echo -e "${_BYellow}INFO:${_creset}  $*" >&2; }
+
+clean_stdin() {
+    if [[ $(uname -s) != 'Darwin' ]]; then
+        while read -r -n1 -t 0.1; do : ; done
+    fi
+}
+
+wait_key(){
+    # usage: waitKEY [<timeout in sec>]
+
+    clean_stdin
+    local _t=$1
+    local msg="${MSG}"
+    [[ -z "$msg" ]] && msg="${_Green}** press any [${_BCyan}KEY${_Green}] to continue **${_creset}"
+
+    [[ -n $FORCE_TIMEOUT ]] && _t=$FORCE_TIMEOUT
+    [[ -n $_t ]] && _t="-t $_t"
+    printf "$msg"
+    # shellcheck disable=SC2086
+    read -r -s -n1 $_t
+    echo
+    clean_stdin
+}
+
+ask_yn() {
+    # usage: ask_yn <prompt-text> [Ny|Yn] [<timeout in sec>]
+
+    local EXIT_YES=0 # exit status 0 --> successful
+    local EXIT_NO=1  # exit status 1 --> error code
+
+    local _t=$3
+    [[ -n $FORCE_TIMEOUT ]] && _t=$FORCE_TIMEOUT
+    [[ -n $_t ]] && _t="-t $_t"
+    case "${FORCE_SELECTION:-${2}}" in
+        Y) return ${EXIT_YES} ;;
+        N) return ${EXIT_NO} ;;
+        Yn)
+            local exit_val=${EXIT_YES}
+            local choice="[${_BGreen}YES${_creset}/no]"
+            local default="Yes"
+            ;;
+        *)
+            local exit_val=${EXIT_NO}
+            local choice="[${_BGreen}NO${_creset}/yes]"
+            local default="No"
+            ;;
+    esac
+    echo
+    while true; do
+        clean_stdin
+        printf "$1 ${choice} "
+        # shellcheck disable=SC2086
+        read -r -n1 $_t
+        if [[ -z $REPLY ]]; then
+            printf "$default\n"; break
+        elif [[ $REPLY =~ ^[Yy]$ ]]; then
+            exit_val=${EXIT_YES}
+            printf "\n"
+            break
+        elif [[ $REPLY =~ ^[Nn]$ ]]; then
+            exit_val=${EXIT_NO}
+            printf "\n"
+            break
+        fi
+        _t=""
+        err_msg "invalid choice"
+    done
+    clean_stdin
+    return $exit_val
+}
+
+tee_stderr () {
+
+    # usage::
+    #   tee_stderr 1 <<EOF | python -i
+    #   print("hello")
+    #   EOF
+    #   ...
+    #   >>> print("hello")
+    #    hello
+
+    local _t="0";
+    if [[ -n $1 ]] ; then _t="$1"; fi
+
+    (while read -r line; do
+         # shellcheck disable=SC2086
+         sleep $_t
+         echo -e "$line" >&2
+         echo "$line"
+    done)
+}
+
+prefix_stdout () {
+    # usage: <cmd> | prefix_stdout [prefix]
+
+    local prefix="${_BYellow}-->|${_creset}"
+
+    if [[ -n $1 ]] ; then prefix="$1"; fi
+
+    # shellcheck disable=SC2162
+    (while IFS= read line; do
+        echo -e "${prefix}$line"
+    done)
+}
+
+append_line() {
+
+    # usage: append_line <line> <file>
+    #
+    # Append line if not exists, create file if not exists. E.g::
+    #
+    #     append_line 'source ~/.foo' ~/bashrc
+
+    local LINE=$1
+    local FILE=$2
+    grep -qFs -- "$LINE" "$FILE" || echo "$LINE" >> "$FILE"
+}
+
+cache_download() {
+
+    # usage: cache_download <url> <local-filename>
+
+    local exit_value=0
+
+    if [[ -n ${SUDO_USER} ]]; then
+        sudo -u "${SUDO_USER}" mkdir -p "${CACHE}"
+    else
+        mkdir -p "${CACHE}"
+    fi
+
+    if [[ -f "${CACHE}/$2" ]] ; then
+        info_msg "already cached: $1"
+        info_msg "  --> ${CACHE}/$2"
+    fi
+
+    if [[ ! -f "${CACHE}/$2" ]]; then
+        info_msg "caching: $1"
+        info_msg "  --> ${CACHE}/$2"
+        if [[ -n ${SUDO_USER} ]]; then
+            sudo -u "${SUDO_USER}" wget --progress=bar -O "${CACHE}/$2" "$1" ; exit_value=$?
+        else
+            wget --progress=bar -O "${CACHE}/$2" "$1" ; exit_value=$?
+        fi
+        if [[ ! $exit_value = 0 ]]; then
+            err_msg "failed to download: $1"
+        fi
+    fi
+}
+
+backup_file() {
+
+    # usage: backup_file /path/to/file.foo
+
+    local stamp
+    stamp=$(date +"_%Y%m%d_%H%M%S")
+    info_msg "create backup: ${1}${stamp}"
+    cp -a "${1}" "${1}${stamp}"
+}
+
+choose_one() {
+
+    # usage:
+    #
+    #   DEFAULT_SELECT= 2 \
+    #     choose_one <name> "your selection?" "Coffee" "Coffee with milk"
+
+    local default=${DEFAULT_SELECT-1}
+    local REPLY
+    local env_name=$1 && shift
+    local choice=$1;
+    local max="${#@}"
+    local _t
+    [[ -n $FORCE_TIMEOUT ]] && _t=$FORCE_TIMEOUT
+    [[ -n $_t ]] && _t="-t $_t"
+
+    list=("$@")
+    echo -e "${_BGreen}Menu::${_creset}"
+    for ((i=1; i<= $((max -1)); i++)); do
+        if [[ "$i" == "$default" ]]; then
+            echo -e "  ${_BGreen}$i.${_creset}) ${list[$i]} [default]"
+        else
+            echo -e "  $i.) ${list[$i]}"
+        fi
+    done
+    while true; do
+        clean_stdin
+        printf "$1 [${_BGreen}$default${_creset}] "
+
+        if (( 10 > max )); then
+            # shellcheck disable=SC2086
+            read -r -n1 $_t
+        else
+            # shellcheck disable=SC2086,SC2229
+            read -r $_t
+        fi
+        # selection fits
+        [[ $REPLY =~ ^-?[0-9]+$ ]] && (( REPLY > 0 )) && (( REPLY < max )) && break
+
+        # take default
+        [[ -z $REPLY ]] && REPLY=$default && break
+
+        _t=""
+        err_msg "invalid choice"
+    done
+    eval "$env_name"='${list[${REPLY}]}'
+    echo
+    clean_stdin
+}
+
+install_template() {
+
+    # usage:
+    #
+    #     install_template [--no-eval] [--variant=<name>] \
+    #                      {file} [{owner} [{group} [{chmod}]]]
+    #
+    # E.g. the origin of variant 'raw' of /etc/updatedb.conf is::
+    #
+    #    ${TEMPLATES}/etc/updatedb.conf:raw
+    #
+    # To install variant 'raw' of /etc/updatedb.conf without evaluated
+    # replacements you can use::
+    #
+    #    install_template --variant=raw --no-eval \
+    #                     /etc/updatedb.conf root root 644
+
+    local _reply=""
+    local do_eval=1
+    local variant=""
+    local pos_args=("$0")
+
+    for i in "$@"; do
+        case $i in
+            --no-eval) do_eval=0; shift ;;
+            --variant=*) variant=":${i#*=}"; shift ;;
+            *) pos_args+=("$i") ;;
+        esac
+    done
+
+    local dst="${pos_args[1]}"
+    local template_origin="${TEMPLATES}${dst}${variant}"
+    local template_file="${TEMPLATES}${dst}"
+
+    local owner="${pos_args[2]-$(id -un)}"
+    local group="${pos_args[3]-$(id -gn)}"
+    local chmod="${pos_args[4]-644}"
+
+    info_msg "install (eval=$do_eval): ${dst}"
+    [[ -n $variant ]] && info_msg "variant --> ${variant}"
+
+    if [[ ! -f "${template_origin}" ]] ; then
+        err_msg "${template_origin} does not exists"
+        err_msg "... can't install $dst"
+        wait_key 30
+        return 42
+    fi
+
+    if [[ "$do_eval" == "1" ]]; then
+        template_file="${CACHE}${dst}${variant}"
+        info_msg "BUILD template ${template_file}"
+        if [[ -n ${SUDO_USER} ]]; then
+            sudo -u "${SUDO_USER}" mkdir -p "$(dirname "${template_file}")"
+        else
+            mkdir -p "$(dirname "${template_file}")"
+        fi
+        # shellcheck disable=SC2086
+        eval "echo \"$(cat ${template_origin})\"" > "${template_file}"
+        if [[ -n ${SUDO_USER} ]]; then
+            chown "${SUDO_USER}:${SUDO_USER}" "${template_file}"
+        fi
+    else
+        template_file=$template_origin
+    fi
+
+    mkdir -p "$(dirname "${dst}")"
+
+    if [[ ! -f "${dst}" ]]; then
+        info_msg "install: ${template_file}"
+        sudo -H install -v -o "${owner}" -g "${group}" -m "${chmod}" \
+             "${template_file}" "${dst}" | prefix_stdout
+        return $?
+    fi
+
+    if [[ -f "${dst}" ]] && cmp --silent "${template_file}" "${dst}" ; then
+        info_msg "file ${dst} allready installed"
+        return 0
+    fi
+
+    info_msg "diffrent file ${dst} allready exists on this host"
+
+    while true; do
+        choose_one _reply "choose next step with file $dst" \
+                   "replace file" \
+                   "leave file unchanged" \
+                   "interactiv shell" \
+                   "diff files"
+
+        case $_reply in
+            "replace file")
+                info_msg "install: ${template_file}"
+                sudo -H install -v -o "${owner}" -g "${group}" -m "${chmod}" \
+                     "${template_file}" "${dst}" | prefix_stdout
+                break
+                ;;
+            "leave file unchanged")
+                break
+                ;;
+            "interactiv shell")
+                echo -e "// edit ${_Red}${dst}${_creset} to your needs"
+                echo -e "// exit with [${_BCyan}CTRL-D${_creset}]"
+                sudo -H -u "${owner}" -i
+                $DIFF_CMD "${dst}" "${template_file}"
+                echo
+                echo -e "// ${_BBlack}did you edit file ...${_creset}"
+                echo -en "//  ${_Red}${dst}${_creset}"
+                if ask_yn "//${_BBlack}... to your needs?${_creset}"; then
+                    break
+                fi
+                ;;
+            "diff files")
+                $DIFF_CMD "${dst}" "${template_file}" | prefix_stdout
+        esac
+    done
+}
+
+
+service_is_available() {
+
+    # usage:  service_is_available <URL>
+
+    [[ -z $1 ]] && die_caller 42 "missing argument <URL>"
+    local URL="$1"
+    http_code=$(curl -H 'Cache-Control: no-cache' \
+         --silent -o /dev/null --head --write-out '%{http_code}' --insecure \
+         "${URL}")
+    exit_val=$?
+    if [[ $exit_val = 0 ]]; then
+        info_msg "got $http_code from ${URL}"
+    fi
+    case "$http_code" in
+        404|410|423) exit_val=$http_code;;
+    esac
+    return "$exit_val"
+}
+
+# golang
+# ------
+
+go_is_available() {
+
+    # usage:  go_is_available $SERVICE_USER && echo "go is installed!"
+
+    sudo -i -u "${1}" which go &>/dev/null
+}
+
+install_go() {
+
+    # usage:  install_go "${GO_PKG_URL}" "${GO_TAR}" "${SERVICE_USER}"
+
+    local _svcpr="  ${_Yellow}|${3}|${_creset} "
+
+    rst_title "Install Go in user's HOME" section
+
+    rst_para "download and install go binary .."
+    cache_download "${1}" "${2}"
+
+    tee_stderr 0.1 <<EOF | sudo -i -u "${3}" | prefix_stdout "$_svcpr"
+echo \$PATH
+echo \$GOPATH
+mkdir -p \$HOME/local
+rm -rf \$HOME/local/go
+tar -C \$HOME/local -xzf ${CACHE}/${2}
+EOF
+    sudo -i -u "${3}" <<EOF | prefix_stdout
+! which go >/dev/null &&  echo "ERROR - Go Installation not found in PATH!?!"
+which go >/dev/null &&  go version && echo "congratulations -- Go installation OK :)"
+EOF
+}
+
+# system accounts
+# ---------------
+
+service_account_is_available() {
+
+    # usage:  service_account_is_available "$SERVICE_USER" && echo "OK"
+
+    sudo -i -u "$1" echo \$HOME &>/dev/null
+}
+
+drop_service_account() {
+
+    # usage:  drop_service_account "${SERVICE_USER}"
+
+    rst_title "Drop ${1} HOME" section
+    if ask_yn "Do you really want to drop ${1} home folder?"; then
+        userdel -r -f "${1}" 2>&1 | prefix_stdout
+    else
+        rst_para "Leave HOME folder $(du -sh "${1}") unchanged."
+    fi
+}
+
+interactive_shell(){
+
+    # usage:  interactive_shell "${SERVICE_USER}"
+
+    echo -e "// exit with [${_BCyan}CTRL-D${_creset}]"
+    sudo -H -u "${1}" -i
+}
+
+
+# systemd
+# -------
+
+SYSTEMD_UNITS="${SYSTEMD_UNITS:-/lib/systemd/system}"
+
+systemd_install_service() {
+
+    # usage:  systemd_install_service "${SERVICE_NAME}" "${SERVICE_SYSTEMD_UNIT}"
+
+    rst_title "Install System-D Unit ${1}" section
+    echo
+    install_template "${2}" root root 644
+    wait_key
+    systemd_activate_service "${1}"
+}
+
+systemd_remove_service() {
+
+    # usage:  systemd_remove_service "${SERVICE_NAME}" "${SERVICE_SYSTEMD_UNIT}"
+
+    if ! ask_yn "Do you really want to deinstall systemd unit ${1}?"; then
+        return 42
+    fi
+    systemd_deactivate_service "${1}"
+    rm "${2}"  2>&1 | prefix_stdout
+}
+
+systemd_activate_service() {
+
+    # usage:  systemd_activate_service "${SERVICE_NAME}"
+
+    rst_title "Activate ${1} (service)" section
+    echo
+    tee_stderr <<EOF | bash 2>&1
+systemctl enable  ${1}.service
+systemctl restart ${1}.service
+EOF
+    tee_stderr <<EOF | bash 2>&1
+systemctl status --no-pager ${1}.service
+EOF
+}
+
+systemd_deactivate_service() {
+
+    # usage:  systemd_deactivate_service "${SERVICE_NAME}"
+
+    rst_title "De-Activate ${1} (service)" section
+    echo
+    tee_stderr <<EOF | bash 2>&1 | prefix_stdout
+systemctl stop    ${1}.service
+systemctl disable ${1}.service
+EOF
+}
+
+systemd_restart_service() {
+
+    # usage:  systemd_restart_service "${SERVICE_NAME}"
+
+    rst_title "Restart ${1} (service)" section
+    echo
+    tee_stderr <<EOF | bash 2>&1
+systemctl restart ${1}.service
+EOF
+    tee_stderr <<EOF | bash 2>&1
+systemctl status --no-pager ${1}.service
+EOF
+}
+
+
+# nginx
+# -----
+
+nginx_distro_setup() {
+    # shellcheck disable=SC2034
+
+    NGINX_DEFAULT_SERVER=/etc/nginx/nginx.conf
+
+    # Including *location* directives from a dedicated config-folder into the
+    # server directive is, what what fedora (already) does.
+    NGINX_APPS_ENABLED="/etc/nginx/default.d"
+
+    # We add a apps-available folder and linking configurations into the
+    # NGINX_APPS_ENABLED folder.  See also nginx_include_apps_enabled().
+    NGINX_APPS_AVAILABLE="/etc/nginx/default.apps-available"
+
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            NGINX_PACKAGES="nginx"
+            NGINX_DEFAULT_SERVER=/etc/nginx/sites-available/default
+            ;;
+        arch-*)
+            NGINX_PACKAGES="nginx-mainline"
+            ;;
+        fedora-*)
+            NGINX_PACKAGES="nginx"
+            ;;
+        *)
+            err_msg "$DIST_ID-$DIST_VERS: nginx not yet implemented"
+            ;;
+    esac
+}
+nginx_distro_setup
+
+install_nginx(){
+    info_msg "installing nginx ..."
+    pkg_install "${NGINX_PACKAGES}"
+    case $DIST_ID-$DIST_VERS in
+        arch-*|fedora-*)
+            systemctl enable nginx
+            systemctl start nginx
+            ;;
+    esac
+}
+
+nginx_is_installed() {
+    command -v nginx &>/dev/null
+}
+
+nginx_reload() {
+
+    info_msg "reload nginx .."
+    echo
+    if ! nginx -t; then
+       err_msg "testing nginx configuration failed"
+       return 42
+    fi
+    systemctl restart nginx
+}
+
+nginx_install_app() {
+
+    # usage:  nginx_install_app [<template option> ...] <myapp>
+    #
+    # <template option>:   see install_template
+
+    local template_opts=()
+    local pos_args=("$0")
+
+    for i in "$@"; do
+        case $i in
+            -*) template_opts+=("$i");;
+            *)  pos_args+=("$i");;
+        esac
+    done
+
+    nginx_include_apps_enabled "${NGINX_DEFAULT_SERVER}"
+
+    install_template "${template_opts[@]}" \
+                     "${NGINX_APPS_AVAILABLE}/${pos_args[1]}" \
+                     root root 644
+    nginx_enable_app "${pos_args[1]}"
+    info_msg "installed nginx app: ${pos_args[1]}"
+}
+
+nginx_include_apps_enabled() {
+
+    # Add the *NGINX_APPS_ENABLED* infrastruture to a nginx server block.  Such
+    # infrastruture is already known from fedora, including apps (location
+    # directives) from the /etc/nginx/default.d folder into the *default* nginx
+    # server.
+
+    # usage: nginx_include_apps_enabled <config-file>
+    #
+    #   config-file: Config file with server directive in.
+
+    [[ -z $1 ]] && die_caller 42 "missing argument <config-file>"
+    local server_conf="$1"
+
+    # include /etc/nginx/default.d/*.conf;
+    local include_directive="include ${NGINX_APPS_ENABLED}/*.conf;"
+    local include_directive_re="^\s*include ${NGINX_APPS_ENABLED}/\*\.conf;"
+
+    info_msg "checking existence: '${include_directive}' in file  ${server_conf}"
+    if grep "${include_directive_re}" "${server_conf}"; then
+        info_msg "OK, already exists."
+        return
+    fi
+
+    info_msg "add missing directive: '${include_directive}'"
+    cp "${server_conf}" "${server_conf}.bak"
+
+    (
+        local line
+        local stage=0
+        while IFS=  read -r line
+        do
+            echo "$line"
+            if [[ $stage = 0 ]]; then
+                if [[ $line =~ ^[[:space:]]*server*[[:space:]]*\{ ]]; then
+                    stage=1
+                fi
+            fi
+
+            if [[ $stage = 1 ]]; then
+                echo "        # Load configuration files for the default server block."
+                echo "        $include_directive"
+                echo ""
+                stage=2
+            fi
+        done < "${server_conf}.bak"
+    ) > "${server_conf}"
+
+}
+
+nginx_remove_app() {
+
+    # usage:  nginx_remove_app <myapp.conf>
+
+    info_msg "remove nginx app: $1"
+    nginx_dissable_app "$1"
+    rm -f "${NGINX_APPS_AVAILABLE}/$1"
+}
+
+nginx_enable_app() {
+
+    # usage:  nginx_enable_app <myapp.conf>
+
+    local CONF="$1"
+
+    info_msg "enable nginx app: ${CONF}"
+    mkdir -p "${NGINX_APPS_ENABLED}"
+    rm -f "${NGINX_APPS_ENABLED}/${CONF}"
+    ln -s "${NGINX_APPS_AVAILABLE}/${CONF}" "${NGINX_APPS_ENABLED}/${CONF}"
+    nginx_reload
+}
+
+nginx_dissable_app() {
+
+    # usage:  nginx_disable_app <myapp.conf>
+
+    local CONF="$1"
+
+    info_msg "disable nginx app: ${CONF}"
+    rm -f "${NGINX_APPS_ENABLED}/${CONF}"
+    nginx_reload
+}
+
+
+# Apache
+# ------
+
+apache_distro_setup() {
+    # shellcheck disable=SC2034
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            # debian uses the /etc/apache2 path, while other distros use
+            # the apache default at /etc/httpd
+            APACHE_SITES_AVAILABLE="/etc/apache2/sites-available"
+            APACHE_SITES_ENABLED="/etc/apache2/sites-enabled"
+            APACHE_MODULES="/usr/lib/apache2/modules"
+            APACHE_PACKAGES="apache2"
+            ;;
+        arch-*)
+            APACHE_SITES_AVAILABLE="/etc/httpd/sites-available"
+            APACHE_SITES_ENABLED="/etc/httpd/sites-enabled"
+            APACHE_MODULES="modules"
+            APACHE_PACKAGES="apache"
+            ;;
+        fedora-*)
+            APACHE_SITES_AVAILABLE="/etc/httpd/sites-available"
+            APACHE_SITES_ENABLED="/etc/httpd/sites-enabled"
+            APACHE_MODULES="modules"
+            APACHE_PACKAGES="httpd"
+            ;;
+        *)
+            err_msg "$DIST_ID-$DIST_VERS: apache not yet implemented"
+            ;;
+    esac
+}
+
+apache_distro_setup
+
+install_apache(){
+    info_msg "installing apache ..."
+    pkg_install "$APACHE_PACKAGES"
+    case $DIST_ID-$DIST_VERS in
+        arch-*|fedora-*)
+            if ! grep "IncludeOptional sites-enabled" "/etc/httpd/conf/httpd.conf"; then
+                echo "IncludeOptional sites-enabled/*.conf" >> "/etc/httpd/conf/httpd.conf"
+            fi
+            systemctl enable httpd
+            systemctl start httpd
+            ;;
+    esac
+}
+
+apache_is_installed() {
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*) (command -v apachectl) &>/dev/null;;
+        arch-*) (command -v httpd) &>/dev/null;;
+        fedora-*) (command -v httpd) &>/dev/null;;
+    esac
+}
+
+apache_reload() {
+
+    info_msg "reload apache .."
+    echo
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            sudo -H apachectl configtest
+            sudo -H systemctl force-reload apache2
+            ;;
+        arch-*| fedora-*)
+            sudo -H httpd -t
+            sudo -H systemctl force-reload httpd
+            ;;
+    esac
+}
+
+apache_install_site() {
+
+    # usage:  apache_install_site [<template option> ...] <mysite.conf>
+    #
+    # <template option>:   see install_template
+
+    local template_opts=()
+    local pos_args=("$0")
+
+    for i in "$@"; do
+        case $i in
+            -*) template_opts+=("$i");;
+            *)  pos_args+=("$i");;
+        esac
+    done
+
+    install_template "${template_opts[@]}" \
+                     "${APACHE_SITES_AVAILABLE}/${pos_args[1]}" \
+                     root root 644
+    apache_enable_site "${pos_args[1]}"
+    info_msg "installed apache site: ${pos_args[1]}"
+}
+
+apache_remove_site() {
+
+    # usage:  apache_remove_site <mysite.conf>
+
+    info_msg "remove apache site: $1"
+    apache_dissable_site "$1"
+    rm -f "${APACHE_SITES_AVAILABLE}/$1"
+}
+
+apache_enable_site() {
+
+    # usage:  apache_enable_site <mysite.conf>
+
+    local CONF="$1"
+
+    info_msg "enable apache site: ${CONF}"
+
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            sudo -H a2ensite -q "${CONF}"
+            ;;
+        arch-*)
+            mkdir -p "${APACHE_SITES_ENABLED}"
+            rm -f "${APACHE_SITES_ENABLED}/${CONF}"
+            ln -s "${APACHE_SITES_AVAILABLE}/${CONF}" "${APACHE_SITES_ENABLED}/${CONF}"
+            ;;
+        fedora-*)
+            mkdir -p "${APACHE_SITES_ENABLED}"
+            rm -f "${APACHE_SITES_ENABLED}/${CONF}"
+            ln -s "${APACHE_SITES_AVAILABLE}/${CONF}" "${APACHE_SITES_ENABLED}/${CONF}"
+            ;;
+    esac
+    apache_reload
+}
+
+apache_dissable_site() {
+
+    # usage:  apache_disable_site <mysite.conf>
+
+    local CONF="$1"
+
+    info_msg "disable apache site: ${CONF}"
+
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            sudo -H a2dissite -q "${CONF}"
+            ;;
+        arch-*)
+            rm -f "${APACHE_SITES_ENABLED}/${CONF}"
+            ;;
+        fedora-*)
+            rm -f "${APACHE_SITES_ENABLED}/${CONF}"
+            ;;
+    esac
+    apache_reload
+}
+
+# uWSGI
+# -----
+
+uWSGI_SETUP="${uWSGI_SETUP:=/etc/uwsgi}"
+uWSGI_USER=
+uWSGI_GROUP=
+
+# How distros manage uWSGI apps is very different.  From uWSGI POV read:
+# - https://uwsgi-docs.readthedocs.io/en/latest/Management.html
+
+uWSGI_distro_setup() {
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            # init.d --> /usr/share/doc/uwsgi/README.Debian.gz
+            # For uWSGI debian uses the LSB init process, this might be changed
+            # one day, see https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=833067
+            uWSGI_APPS_AVAILABLE="${uWSGI_SETUP}/apps-available"
+            uWSGI_APPS_ENABLED="${uWSGI_SETUP}/apps-enabled"
+            uWSGI_PACKAGES="uwsgi"
+            ;;
+        arch-*)
+            # systemd --> /usr/lib/systemd/system/uwsgi@.service
+            # For uWSGI archlinux uses systemd template units, see
+            # - http://0pointer.de/blog/projects/instances.html
+            # - https://uwsgi-docs.readthedocs.io/en/latest/Systemd.html#one-service-per-app-in-systemd
+            uWSGI_APPS_AVAILABLE="${uWSGI_SETUP}/apps-archlinux"
+            uWSGI_APPS_ENABLED="${uWSGI_SETUP}"
+            uWSGI_PACKAGES="uwsgi"
+            ;;
+        fedora-*)
+            # systemd --> /usr/lib/systemd/system/uwsgi.service
+            # The unit file starts uWSGI in emperor mode (/etc/uwsgi.ini), see
+            # - https://uwsgi-docs.readthedocs.io/en/latest/Emperor.html
+            uWSGI_APPS_AVAILABLE="${uWSGI_SETUP}/apps-available"
+            uWSGI_APPS_ENABLED="${uWSGI_SETUP}.d"
+            uWSGI_PACKAGES="uwsgi"
+            uWSGI_USER="uwsgi"
+            uWSGI_GROUP="uwsgi"
+            ;;
+        *)
+            err_msg "$DIST_ID-$DIST_VERS: uWSGI not yet implemented"
+            ;;
+esac
+}
+
+uWSGI_distro_setup
+
+install_uwsgi(){
+    info_msg "installing uwsgi ..."
+    pkg_install "$uWSGI_PACKAGES"
+    case $DIST_ID-$DIST_VERS in
+        fedora-*)
+            # enable & start should be called once at uWSGI installation time
+            systemctl enable uwsgi
+            systemctl restart uwsgi
+            ;;
+    esac
+}
+
+uWSGI_restart() {
+
+    # usage:  uWSGI_restart() <myapp.ini>
+
+    local CONF="$1"
+
+    [[ -z $CONF ]] && die_caller 42 "missing argument <myapp.ini>"
+    info_msg "restart uWSGI service"
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            # the 'service' method seems broken in that way, that it (re-)starts
+            # the whole uwsgi process.
+            service uwsgi restart "${CONF%.*}"
+            ;;
+        arch-*)
+            # restart systemd template instance
+            if uWSGI_app_available "${CONF}"; then
+                systemctl restart "uwsgi@${CONF%.*}"
+            else
+                info_msg "[uWSGI:systemd-template] ${CONF} not installed (no need to restart)"
+            fi
+            ;;
+        fedora-*)
+            # in emperor mode, just touch the file to restart
+            if uWSGI_app_enabled "${CONF}"; then
+                touch "${uWSGI_APPS_ENABLED}/${CONF}"
+                # it seems, there is a polling time in between touch and restart
+                # of the service.
+                sleep 3
+            else
+                info_msg "[uWSGI:emperor] ${CONF} not installed (no need to restart)"
+            fi
+            ;;
+        *)
+            err_msg "$DIST_ID-$DIST_VERS: uWSGI not yet implemented"
+            return 42
+            ;;
+    esac
+}
+
+uWSGI_prepare_app() {
+
+    # usage:  uWSGI_prepare_app <myapp.ini>
+
+    [[ -z $1 ]] && die_caller 42 "missing argument <myapp.ini>"
+
+    local APP="${1%.*}"
+
+    case $DIST_ID-$DIST_VERS in
+        fedora-*)
+            # in emperor mode, the uwsgi user is the owner of the sockets
+            info_msg "prepare (uwsgi:uwsgi)  /run/uwsgi/app/${APP}"
+            mkdir -p "/run/uwsgi/app/${APP}"
+            chown -R "uwsgi:uwsgi"  "/run/uwsgi/app/${APP}"
+            ;;
+        *)
+            info_msg "prepare (${SERVICE_USER}:${SERVICE_GROUP})  /run/uwsgi/app/${APP}"
+            mkdir -p "/run/uwsgi/app/${APP}"
+            chown -R "${SERVICE_USER}:${SERVICE_GROUP}"  "/run/uwsgi/app/${APP}"
+            ;;
+    esac
+}
+
+
+uWSGI_app_available() {
+    # usage:  uWSGI_app_available <myapp.ini>
+    local CONF="$1"
+
+    [[ -z $CONF ]] && die_caller 42 "missing argument <myapp.ini>"
+    [[ -f "${uWSGI_APPS_AVAILABLE}/${CONF}" ]]
+}
+
+uWSGI_install_app() {
+
+    # usage:  uWSGI_install_app [<template option> ...] <myapp.ini>
+    #
+    # <template option>:  see install_template
+
+    local pos_args=("$0")
+
+    for i in "$@"; do
+        case $i in
+            -*) template_opts+=("$i");;
+            *)  pos_args+=("$i");;
+        esac
+    done
+    uWSGI_prepare_app "${pos_args[1]}"
+    mkdir -p "${uWSGI_APPS_AVAILABLE}"
+    install_template "${template_opts[@]}" \
+                     "${uWSGI_APPS_AVAILABLE}/${pos_args[1]}" \
+                     root root 644
+    uWSGI_enable_app "${pos_args[1]}"
+    uWSGI_restart "${pos_args[1]}"
+    info_msg "uWSGI app: ${pos_args[1]} is installed"
+}
+
+uWSGI_remove_app() {
+
+    # usage:  uWSGI_remove_app <myapp.ini>
+
+    local CONF="$1"
+
+    [[ -z $CONF ]] && die_caller 42 "missing argument <myapp.ini>"
+    info_msg "remove uWSGI app: ${CONF}"
+    uWSGI_disable_app "${CONF}"
+    uWSGI_restart "${CONF}"
+    rm -f "${uWSGI_APPS_AVAILABLE}/${CONF}"
+}
+
+uWSGI_app_enabled() {
+    # usage:  uWSGI_app_enabled <myapp.ini>
+
+    local exit_val=0
+    local CONF="$1"
+
+    [[ -z $CONF ]] && die_caller 42 "missing argument <myapp.ini>"
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            [[ -f "${uWSGI_APPS_ENABLED}/${CONF}" ]]
+            exit_val=$?
+            ;;
+        arch-*)
+            systemctl -q is-enabled "uwsgi@${CONF%.*}"
+            exit_val=$?
+            ;;
+        fedora-*)
+            [[ -f "${uWSGI_APPS_ENABLED}/${CONF}" ]]
+            exit_val=$?
+            ;;
+        *)
+            # FIXME
+            err_msg "$DIST_ID-$DIST_VERS: uWSGI not yet implemented"
+            exit_val=1
+            ;;
+    esac
+    return $exit_val
+}
+
+# shellcheck disable=SC2164
+uWSGI_enable_app() {
+
+    # usage:   uWSGI_enable_app <myapp.ini>
+
+    local CONF="$1"
+
+    [[ -z $CONF ]] && die_caller 42 "missing argument <myapp.ini>"
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            mkdir -p "${uWSGI_APPS_ENABLED}"
+            rm -f "${uWSGI_APPS_ENABLED}/${CONF}"
+            ln -s "${uWSGI_APPS_AVAILABLE}/${CONF}" "${uWSGI_APPS_ENABLED}/${CONF}"
+            info_msg "enabled uWSGI app: ${CONF} (restart required)"
+            ;;
+        arch-*)
+            mkdir -p "${uWSGI_APPS_ENABLED}"
+            rm -f "${uWSGI_APPS_ENABLED}/${CONF}"
+            ln -s "${uWSGI_APPS_AVAILABLE}/${CONF}" "${uWSGI_APPS_ENABLED}/${CONF}"
+            systemctl enable "uwsgi@${CONF%.*}"
+            info_msg "enabled uWSGI app: ${CONF} (restart required)"
+            ;;
+        fedora-*)
+            mkdir -p "${uWSGI_APPS_ENABLED}"
+            rm -f "${uWSGI_APPS_ENABLED}/${CONF}"
+            ln -s "${uWSGI_APPS_AVAILABLE}/${CONF}" "${uWSGI_APPS_ENABLED}/${CONF}"
+            chown "${uWSGI_USER}:${uWSGI_GROUP}" "${uWSGI_APPS_ENABLED}/${CONF}"
+            info_msg "enabled uWSGI app: ${CONF}"
+            ;;
+        *)
+            # FIXME
+            err_msg "$DIST_ID-$DIST_VERS: uWSGI not yet implemented"
+            ;;
+    esac
+}
+
+uWSGI_disable_app() {
+
+    # usage:   uWSGI_disable_app <myapp.ini>
+
+    local CONF="$1"
+
+    [[ -z $CONF ]] && die_caller 42 "missing argument <myapp.ini>"
+    case $DIST_ID-$DIST_VERS in
+        ubuntu-*|debian-*)
+            service uwsgi stop "${CONF%.*}"
+            rm -f "${uWSGI_APPS_ENABLED}/${CONF}"
+            info_msg "disabled uWSGI app: ${CONF} (restart uWSGI required)"
+            ;;
+        arch-*)
+            systemctl stop "uwsgi@${CONF%.*}"
+            systemctl disable "uwsgi@${CONF%.*}"
+            rm -f "${uWSGI_APPS_ENABLED}/${CONF}"
+            ;;
+        fedora-*)
+            # in emperor mode, just remove the app.ini file
+            rm -f "${uWSGI_APPS_ENABLED}/${CONF}"
+            ;;
+        *)
+            # FIXME
+            err_msg "$DIST_ID-$DIST_VERS: uWSGI not yet implemented"
+            ;;
+    esac
+}
+
+# distro's package manager
+# ------------------------
+
+_apt_pkg_info_is_updated=0
+
+pkg_install() {
+
+    # usage: TITEL='install foobar' pkg_install foopkg barpkg
+
+    rst_title "${TITLE:-installation of packages}" section
+    echo -e "\npackage(s)::\n"
+    # shellcheck disable=SC2068
+    echo "  " $@ | $FMT
+
+    if ! ask_yn "Should packages be installed?" Yn 30; then
+        return 42
+    fi
+    case $DIST_ID in
+        ubuntu|debian)
+            if [[ $_apt_pkg_info_is_updated == 0 ]]; then
+                export _apt_pkg_info_is_updated=1
+                apt update
+            fi
+            # shellcheck disable=SC2068
+            apt-get install -m -y $@
+            ;;
+        arch)
+            # shellcheck disable=SC2068
+            pacman -Sy --noconfirm $@
+            ;;
+        fedora)
+            # shellcheck disable=SC2068
+            dnf install -y $@
+            ;;
+    esac
+}
+
+pkg_remove() {
+
+    # usage: TITEL='remove foobar' pkg_remove foopkg barpkg
+
+    rst_title "${TITLE:-remove packages}" section
+    echo -e "\npackage(s)::\n"
+    # shellcheck disable=SC2068
+    echo "  " $@ | $FMT
+
+    if ! ask_yn "Should packages be removed (purge)?" Yn 30; then
+        return 42
+    fi
+    case $DIST_ID in
+        ubuntu|debian)
+            # shellcheck disable=SC2068
+            apt-get purge --autoremove --ignore-missing -y $@
+            ;;
+        arch)
+            # shellcheck disable=SC2068
+            pacman -R --noconfirm $@
+            ;;
+        fedora)
+            # shellcheck disable=SC2068
+            dnf remove -y $@
+            ;;
+    esac
+}
+
+pkg_is_installed() {
+
+    # usage: pkg_is_install foopkg || pkg_install foopkg
+
+    case $DIST_ID in
+        ubuntu|debian)
+            dpkg -l "$1" &> /dev/null
+            return $?
+            ;;
+        arch)
+            pacman -Qsq "$1" &> /dev/null
+            return $?
+            ;;
+        fedora)
+            dnf list -q --installed "$1" &> /dev/null
+            return $?
+            ;;
+    esac
+}
+
+# git tooling
+# -----------
+
+# shellcheck disable=SC2164
+git_clone() {
+
+    # usage:
+    #
+    #    git_clone <url> <name> [<branch> [<user>]]
+    #    git_clone <url> <path> [<branch> [<user>]]
+    #
+    #  First form uses $CACHE/<name> as destination folder, second form clones
+    #  into <path>.  If repository is allready cloned, pull from <branch> and
+    #  update working tree (if needed, the caller has to stash local changes).
+    #
+    #    git clone https://github.com/asciimoo/searx searx-src origin/master searxlogin
+    #
+
+    local url="$1"
+    local dest="$2"
+    local branch="$3"
+    local user="$4"
+    local bash_cmd="bash"
+    local remote="origin"
+
+    if [[ ! "${dest:0:1}" = "/" ]]; then
+        dest="$CACHE/$dest"
+    fi
+
+    [[ -z $branch ]] && branch=master
+    [[ -z $user ]] && [[ -n "${SUDO_USER}" ]] && user="${SUDO_USER}"
+    [[ -n $user ]] && bash_cmd="sudo -H -u $user -i"
+
+    if [[ -d "${dest}" ]] ; then
+        info_msg "already cloned: $dest"
+        tee_stderr 0.1 <<EOF | $bash_cmd 2>&1 |  prefix_stdout "  ${_Yellow}|$user|${_creset} "
+cd "${dest}"
+git checkout -m -B "$branch" --track "$remote/$branch"
+git pull --all
+EOF
+    else
+        info_msg "clone into: $dest"
+        tee_stderr 0.1 <<EOF | $bash_cmd 2>&1 |  prefix_stdout "  ${_Yellow}|$user|${_creset} "
+mkdir -p "$(dirname "$dest")"
+cd "$(dirname "$dest")"
+git clone --branch "$branch" --origin "$remote" "$url" "$(basename "$dest")"
+EOF
+    fi
+}
+
+# containers
+# ----------
+
+in_container() {
+    # Test if shell runs in a container.
+    #
+    # usage:  in_container && echo "process running inside a LXC container"
+    #         in_container || echo "process is not running inside a LXC container"
+    #
+    # sudo_or_exit
+    # hint:   Reads init process environment, therefore root access is required!
+    # to be safe, take a look at the environment of process 1 (/sbin/init)
+    # grep -qa 'container=lxc' /proc/1/environ
+
+    # see lxc_init_container_env
+    [[ -f /.lxcenv ]]
+}
+
+LXC_ENV_FOLDER=
+if in_container; then
+    # shellcheck disable=SC2034
+    LXC_ENV_FOLDER="lxc/$(hostname)/"
+fi
+
+lxc_init_container_env() {
+
+    # usage: lxc_init_container_env <name>
+
+    # Create a /.lxcenv file in the root folder.  Call this once after the
+    # container is inital started and before installing any boilerplate stuff.
+
+    info_msg "create /.lxcenv in container $1"
+    cat <<EOF | lxc exec "${1}" -- bash | prefix_stdout "[${_BBlue}${1}${_creset}] "
+touch "/.lxcenv"
+ls -l "/.lxcenv"
+EOF
+}
+
+# apt packages
+LXC_BASE_PACKAGES_debian="bash git build-essential python3 virtualenv"
+
+# pacman packages
+LXC_BASE_PACKAGES_arch="bash git base-devel python python-virtualenv"
+
+# dnf packages
+LXC_BASE_PACKAGES_fedora="bash git @development-tools python virtualenv"
+
+case $DIST_ID in
+    ubuntu|debian) LXC_BASE_PACKAGES="${LXC_BASE_PACKAGES_debian}" ;;
+    arch)          LXC_BASE_PACKAGES="${LXC_BASE_PACKAGES_arch}" ;;
+    fedora)        LXC_BASE_PACKAGES="${LXC_BASE_PACKAGES_fedora}" ;;
+    *) err_msg "$DIST_ID-$DIST_VERS: pkg_install LXC_BASE_PACKAGES not yet implemented" ;;
+esac
+
+lxc_install_base_packages() {
+    info_msg "install LXC_BASE_PACKAGES in container $1"
+    pkg_install "${LXC_BASE_PACKAGES}"
+}
+
+
+lxc_image_copy() {
+
+    # usage: lxc_copy_image <remote image> <local image>
+    #
+    #        lxc_copy_image "images:ubuntu/19.10"  "ubu1910"
+
+    if lxc_image_exists "local:${LXC_SUITE[i+1]}"; then
+        info_msg "image ${LXC_SUITE[i]} already copied --> ${LXC_SUITE[i+1]}"
+    else
+        info_msg "copy image locally ${LXC_SUITE[i]} --> ${LXC_SUITE[i+1]}"
+        lxc image copy "${LXC_SUITE[i]}" local: \
+            --alias  "${LXC_SUITE[i+1]}" | prefix_stdout
+    fi
+}
+
+lxc_init_container() {
+
+    # usage: lxc_init_container <image name> <container name>
+
+    local image_name="$1"
+    local container_name="$2"
+
+    if lxc info "${container_name}" &>/dev/null; then
+        info_msg "container '${container_name}' already exists"
+    else
+        info_msg "create container instance: ${container_name}"
+        lxc init "local:${image_name}" "${container_name}"
+    fi
+}
+
+lxc_exists(){
+
+    # usage: lxc_exists <name> || echo "container <name> does not exists"
+
+    lxc info "$1" &>/dev/null
+}
+
+lxc_image_exists(){
+    # usage: lxc_image_exists <alias> || echo "image <alias> does locally not exists"
+
+    lxc image info "local:$1" &>/dev/null
+
+}
+
+lxc_delete_container() {
+
+    #  usage: lxc_delete_container <container-name>
+
+    if lxc info "$1" &>/dev/null; then
+        info_msg "stop & delete instance ${_BBlue}${1}${_creset}"
+        lxc stop "$1" &>/dev/null
+        lxc delete "$1" | prefix_stdout
+    else
+        warn_msg "instance '$1' does not exist / can't delete :o"
+    fi
+}
+
+lxc_delete_local_image() {
+
+    #  usage: lxc_delete_local_image <container-name>
+
+    info_msg "delete image 'local:$i'"
+    lxc image delete "local:$i"
+}
+
+
+# IP
+# --
+
+global_IPs(){
+    # usage: global_IPS
+    #
+    # print list of host's SCOPE global addresses and adapters e.g::
+    #
+    #   $ global_IPs
+    #   enp4s0|192.168.1.127
+    #   lxdbr0|10.246.86.1
+    #   lxdbr0|fd42:8c58:2cd:b73f::1
+
+    ip -o addr show | sed -nr 's/[0-9]*:\s*([a-z0-9]*).*inet[6]?\s*([a-z0-9.:]*).*scope global.*/\1|\2/p'
+}
+
+primary_ip() {
+
+    case $DIST_ID in
+        arch)
+            ip -o addr show \
+                | sed -nr 's/[0-9]*:\s*([a-z0-9]*).*inet[6]?\s*([a-z0-9.:]*).*scope global.*/\2/p' \
+                | head -n 1
+            ;;
+        *)  hostname -I | cut -d' ' -f1 ;;
+    esac
+}
+
+# URL
+# ---
+
+url_replace_hostname(){
+
+    # usage:  url_replace_hostname <url> <new hostname>
+
+    # to replace hostname by primary IP::
+    #
+    #   url_replace_hostname http://searx-ubu1604/morty $(primary_ip)
+    #   http://10.246.86.250/morty
+
+    # shellcheck disable=SC2001
+    echo "$1" | sed "s|\(http[s]*://\)[^/]*\(.*\)|\1$2\2|"
+}