utils: add lib.sh containing common shell script

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

.gitignore

@@ -1,6 +1,7 @@
 # to sync with .dockerignore
 .coverage
 coverage/
+cache/
 .installed.cfg
 engines.cfg
 env

Makefile

@@ -77,6 +77,7 @@ test: test.pep8 test.unit test.sh test.robot
 	- make pylint
 
 test.sh:
+	shellcheck -x utils/lib.sh
 
 test.pep8: pyenvinstall
 	$(PY_ENV_ACT); ./manage.sh pep8_check

utils/lib.sh

@@ -0,0 +1,316 @@
+#!/usr/bin/env bash
+# -*- coding: utf-8; mode: sh -*-
+# shellcheck disable=SC2059,SC1117,SC2162,SC2004
+
+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 "$SYSTEMD_UNITS" ]]; then
+    SYSTEMD_UNITS="/lib/systemd/system/"
+fi
+
+sudo_or_exit() {
+    # usage: sudo_or_exit
+
+    if [ ! "$(id -u)" -eq 0 ];  then
+        err_msg "this command requires root (sudo) privilege!" >&2
+        exit 42
+    fi
+}
+
+rst_title() {
+    # usage: rst_title <header-text> [part|chapter|section]
+
+    case ${2-chapter} in
+        part)     printf "\n${1//?/=}\n$1\n${1//?/=}\n";;
+        chapter)  printf "\n${1}\n${1//?/=}\n";;
+        section)  printf "\n${1}\n${1//?/-}\n";;
+        *)
+            err_msg "invalid argument '${2}' in line $(caller)"
+            return 42
+            ;;
+    esac
+}
+
+if command -v fmt >/dev/null; then
+    export FMT="fmt -u"
+else
+    export FMT="cat"
+fi
+
+rst_para() {
+    # usage:  RST_INDENT=1 rst_para "lorem ipsum ..."
+    local prefix=''
+    if ! [[ -z $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
+}
+
+err_msg()  { echo -e "ERROR: $*" >&2; }
+warn_msg() { echo -e "WARN:  $*" >&2; }
+info_msg() { echo -e "INFO:  $*"; }
+
+wait_key(){
+    # usage: waitKEY [<timeout in sec>]
+
+    local _t=$1
+    [[ ! -z $FORCE_TIMEOUT ]] && _t=$FORCE_TIMEOUT
+    [[ ! -z $_t ]] && _t="-t $_t"
+    # shellcheck disable=SC2086
+    read -n1 $_t -p "** press any [KEY] to continue **"
+    echo
+}
+
+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
+    [[ ! -z $FORCE_TIMEOUT ]] && _t=$FORCE_TIMEOUT
+    [[ ! -z $_t ]] && _t="-t $_t"
+    case "${2}" in
+        Yn)
+            local exit_val=${EXIT_YES}
+            local choice="[YES/no]"
+            local default="Yes"
+            ;;
+        *)
+            local exit_val=${EXIT_NO}
+            local choice="[NO/yes]"
+            local default="No"
+            ;;
+    esac
+    echo
+    while true; do
+        printf "$1 ${choice} "
+        # shellcheck disable=SC2086
+        read -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
+    return $exit_val
+}
+
+tee_stderr () {
+
+    # usage::
+    #   tee_stderr 1 <<EOF | python -i
+    #   print("hello")
+    #   EOF
+    #   ...
+    #   >>> print("hello")
+    #    hello
+
+    local _t="0";
+    if [[ ! -z $1 ]] ; then _t="$1"; fi
+
+    (while read line; do
+         # shellcheck disable=SC2086
+         sleep $_t
+         echo -e "$line" >&2
+         echo "$line"
+    done)
+}
+
+prefix_stdout () {
+    # usage: <cmd> | prefix_stdout [prefix]
+
+    local prefix="-->| "
+
+    if [[ ! -z $1 ]] ; then prefix="$1"; fi
+
+    (while IFS= read line; do
+        echo -e "${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 [[ ! -z ${SUDO_USER} ]]; then
+        sudo -u "${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 [[ ! -z ${SUDO_USER} ]]; then
+            sudo -u "${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; then
+            err_msg "failed to download: $1"
+        fi
+    fi
+}
+
+choose_one() {
+
+    # usage:
+    #
+    #   DEFAULT_SELECT= 2 \
+    #     choose_one <name> "your selection?" "Coffee" "Coffee with milk"
+
+    local default=${DEFAULT_SELECT-1}
+    local REPLY
+    local env_name=$1 && shift
+    local choice=$1;
+    local max="${#@}"
+    local _t
+    [[ ! -z $FORCE_TIMEOUT ]] && _t=$FORCE_TIMEOUT
+    [[ ! -z $_t ]] && _t="-t $_t"
+
+    list=("$@")
+    echo -e "Menu::"
+    for ((i=1; i<= $(($max -1)); i++)); do
+        if [[ "$i" == "$default" ]]; then
+            echo -e "  $i.) ${list[$i]} [default]"
+        else
+            echo -e "  $i.) ${list[$i]}"
+        fi
+    done
+    while true; do
+        printf "$1 [$default] "
+
+        if (( 10 > $max )); then
+            # shellcheck disable=SC2086
+            read -n1 $_t
+        else
+            # shellcheck disable=SC2086,SC2229
+            read $_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
+    echo
+    eval "$env_name"='${list[${REPLY}]}'
+}
+
+install_template() {
+
+    # usage:
+    #
+    #     install_template [--no-eval] {file} [{owner} [{group} [{chmod}]]]
+    #
+    #     install_template --no-eval /etc/updatedb.conf root root 644
+
+    local do_eval=0
+    if [[ "$1" == "--no-eval" ]]; then
+        do_eval=1; shift
+    fi
+    local dst="${1}"
+    local owner=${2-$(id -un)}
+    local group=${3-$(id -gn)}
+    local chmod=${4-644}
+    local _reply=""
+
+    info_msg "install: ${dst}"
+
+    if [[ ! -f "${TEMPLATES}${dst}" ]] ; then
+        err_msg "${TEMPLATES}${dst} does not exists"
+        err_msg "... can't install $dst / exit installation with error 42"
+        wait_key 30
+        return 42
+    fi
+
+    local template_file="${TEMPLATES}${dst}"
+    if [[ "$do_eval" == "1" ]]; then
+        info_msg "BUILD template ${template_file}"
+        if [[ -f "${TEMPLATES}${dst}" ]] ; then
+            template_file="${CACHE}${dst}"
+            mkdir -p "$(dirname "${template_file}")"
+            # shellcheck disable=SC2086
+            eval "echo \"$(cat ${TEMPLATES}${dst})\"" > "${template_file}"
+        else
+            err_msg "failed ${template_file}"
+            return 42
+        fi
+    fi
+
+    if [[ -f "${dst}" ]] ; then
+        info_msg "file ${dst} allready exists on this host"
+        choose_one _reply "choose next step with file $dst" \
+                   "replace file" \
+                   "leave file unchanged"
+
+        case $_reply in
+            "replace file")
+                info_msg "install: ${template_file}"
+                sudo -H install -v -o "${owner}" -g "${group}" -m "${chmod}" \
+                     "${template_file}" "${dst}"
+                ;;
+            "leave file unchanged")
+                ;;
+            "interactiv shell")
+                echo "// exit with STRG-D"
+                sudo -H -u "${owner}" -i
+            ;;
+        esac
+
+    else
+        info_msg "install: ${template_file}"
+        sudo -H install -v -o "${owner}" -g "${group}" -m "${chmod}" \
+             "${template_file}" "${dst}"
+    fi
+
+}
+