From d8a2f732b300cdbb892e0878fe87dbb7a0ef6d03 Mon Sep 17 00:00:00 2001
From: Patrick Spek <p.spek@tyil.nl>
Date: Fri, 15 Apr 2022 16:32:43 +0200
Subject: Initial commit

---
 lib/util.bash | 365 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 365 insertions(+)
 create mode 100644 lib/util.bash

(limited to 'lib/util.bash')

diff --git a/lib/util.bash b/lib/util.bash
new file mode 100644
index 0000000..2c10ef4
--- /dev/null
+++ b/lib/util.bash
@@ -0,0 +1,365 @@
+#!/usr/bin/env bash
+
+# Change the working directory. In usage, this is the same as using cd,
+# however,  it will make additional checks to ensure everything is going fine.
+chgdir() {
+	debug "tyilnet/chgdir" "Changing workdir to $1"
+	cd -- "$1" || die "Failed to change directory to $1"
+}
+
+# Read a particular value from a key/value configuration file. Using this
+# function introduces a dependency on awk.
+config() {
+	config_for "${BASHTARD_PLATFORM[fqdn]}" "$@"
+}
+
+config_for() {
+	local default
+	local file
+	local files
+	local host
+	local value
+	local key
+
+	host=$1 ; shift
+	key=$1 ; shift
+	default=$1 ; shift
+
+	files=(
+		"$BASHTARD_ETCDIR/hosts.d/$host"
+		"$BASHTARD_ETCDIR/os.d/${BASHTARD_PLATFORM[key]}"
+		"$BASHTARD_ETCDIR/defaults"
+		"$BASHTARD_BASEDIR/etc/os.d/${BASHTARD_PLATFORM[key]}"
+		"$BASHTARD_BASEDIR/etc/defaults"
+	)
+
+	# Check configuration files
+	for file in "${files[@]}"
+	do
+		[[ ! -f $file ]] && continue
+
+		value="$(awk -F= '$1 == "'"$key"'" { print $NF }' "$file")"
+
+		if [[ -n $value ]]
+		then
+			debug "tyilnet/config_for" "Found $key=$value in $file"
+
+			printf "%s" "$value"
+			return
+		fi
+	done
+
+	# Return default value
+	if [[ -n $default ]]
+	then
+		printf "%s" "$default"
+		return
+	fi
+
+	# Error
+	alert "tyilnet/config_for" "No configuration value for $key"
+}
+
+# Create a datetime stamp. This is a wrapper around the date utility, ensuring
+# that the date being formatted is always in UTC and respect SOURCE_DATE_EPOCH,
+# if it is set.
+datetime() {
+	local date_opts
+
+	# Apply SOURCE_DATE_EPOCH as the date to base off of.
+	if [[ $SOURCE_DATE_EPOCH ]]
+	then
+		date_opts+=("-d@$SOURCE_DATE_EPOCH")
+		date_opts+=("-u")
+	fi
+
+	date "${date_opts[@]}" +"${1:-%FT%T}"
+}
+
+# Log a message as error, and exit the program. This is intended for serious
+# issues that prevent the script from running correctly. The exit code can be
+# specified with -i, or will default to 1.
+die() {
+	local OPTIND
+	local code
+
+	while getopts ":i:" opt
+	do
+		case "$opt" in
+			i) code=$OPTARG ;;
+			*) alert "tyilnet/die" "Unused argument specified: $opt" ;;
+		esac
+	done
+
+	shift $(( OPTIND -1 ))
+
+	alert "$@"
+	exit "${code:-1}"
+}
+
+# Fetch a file from an URL. Using this function introduces a dependency on curl.
+fetch_http() {
+	local OPTIND
+	local buffer
+
+	while getopts ":o:" opt
+	do
+		case "$opt" in
+			o) buffer=$OPTARG ;;
+			*) alert "tyilnet/fetch_http" "Unused argument specified: $opt" ;;
+		esac
+	done
+
+	shift $(( OPTIND -1 ))
+
+	[[ -z $buffer ]] && buffer="$(tmpfile)"
+
+	notice "tyilnet/fetch_http" "Downloading $1 to $buffer"
+
+	for util in curl wget
+	do
+		command -v "$util" > /dev/null || continue
+		"fetch_http_$util" "$1" "$buffer" || continue
+		local exit_code=$?
+
+		printf "%s" "$buffer"
+		return $exit_code
+	done
+
+	die "tyilnet/fetch_http" "Unable to download file over HTTP!"
+}
+
+fetch_http_curl() {
+	curl -Ls "$1" > "$2"
+}
+
+fetch_http_wget() {
+	wget --quiet --output-document "$2" "$1"
+}
+
+# Check if the first argument given appears in the list of all following
+# arguments.
+in_args() {
+	local needle="$1"
+	shift
+
+	for arg in "$@"
+	do
+		[[ $needle == "$arg" ]] && return 0
+	done
+
+	return 1
+}
+
+# Join a list of arguments into a single string. By default, this will join
+# using a ",", but you can set a different character using -c. Note that this
+# only joins with a single character, not a string of characters.
+join_args() {
+	local OPTIND
+	local IFS=","
+
+	while getopts ":c:" opt
+	do
+		case "$opt" in
+			c) IFS="$OPTARG" ;;
+			*) warn "tyilnet/join_args" "Unused opt specified: $opt" ;;
+		esac
+	done
+
+	shift $(( OPTIND - 1))
+
+	printf "%s" "$*"
+}
+
+# OS independent package management
+pkg() {
+	local system="tyilnet/pkg"
+
+	local action=$1 ; shift
+	local app="$(config "pkg.$1" "$(config "app.$1")")" ; shift
+
+	local type
+
+	if [[ -z $app ]]
+	then
+		crit "$system" "No package name for $app"
+		return 1
+	fi
+
+	if [[ "$(type -t pkg_$action)" != "function" ]]
+	then
+		crit "$system" "Invalid package manager action $action"
+		return 1
+	fi
+
+	"pkg_$action" "$app"
+}
+
+pkg_install() {
+	local system="tyilnet/pkg/install"
+
+	local app=$1 ; shift
+
+	case "${BASHTARD_PLATFORM[key]}" in
+		freebsd)       set -- /usr/sbin/pkg install -y "$app" ;;
+		linux-debian*) set -- apt install -y "$app" ;;
+		linux-gentoo)  set -- emerge --ask=n "$app" ;;
+		*)
+			crit "$system" "No package manager configured for ${BASHTARD_PLATFORM[key]}"
+			return 1
+			;;
+	esac
+
+	notice "$system" "$*"
+	$@
+}
+
+# OS independent service management.
+svc() {
+	local system="tyilnet/svc"
+
+	local service
+	local action
+
+	service="$(config svc.$1)" ; shift
+	action=$1 ; shift
+
+	if [[ -z $service ]]
+	then
+		crit "$system" "No service name for $service"
+		return 1
+	fi
+
+	if [[ "$(type -t svc_$action)" != "function" ]]
+	then
+		crit "$system" "Invalid service manager action $action"
+		return 1
+	fi
+
+	"svc_$action" "$service"
+}
+
+svc_enable() {
+	local system="tyilnet/svc/enable"
+
+	local service=$1
+
+	case "${BASHTARD_PLATFORM[key]}" in
+		linux-gentoo) set -- /sbin/rc-update add "$service" ;;
+		linux-*)      set -- systemctl enable "$service" ;;
+		*)
+			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
+			return 1
+	esac
+
+	notice "$system" "$*"
+	$@
+}
+
+svc_restart() {
+	local system="tyilnet/svc/restart"
+
+	local service=$1
+
+	case "${BASHTARD_PLATFORM[key]}" in
+		freebsd)      set -- service "$service" restart ;;
+		linux-gentoo) set -- /sbin/rc-service "$service" restart ;;
+		linux-*)      set -- systemctl restart "$service" ;;
+		*)
+			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
+			return 1
+	esac
+
+	notice "$system" "$*"
+	$@
+}
+
+svc_start() {
+	local system="tyilnet/svc/start"
+
+	local service=$1
+
+	case "${BASHTARD_PLATFORM[key]}" in
+		freebsd)      set -- service "$service" start ;;
+		linux-gentoo) set -- /sbin/rc-service "$service" start ;;
+		linux-*)      set -- systemctl start "$service" ;;
+		*)
+			crit "$system" "No service manager configured for ${BASHTARD_PLATFORM[key]}"
+			return 1
+	esac
+
+	notice "$system" "$*"
+	$@
+}
+
+template()
+{
+	local file="$BASEDIR/etc/templates/$1" ; shift
+	local sedfile="$(tmpfile)"
+
+	if [[ ! -f $file ]]
+	then
+		crit "tyilnet/template" "Tried to render template from $file, but it doesn't exist"
+		return
+	fi
+
+	for kv in "$@"
+	do
+		debug "tyilnet/template" "Adding $kv to sedfile at $sedfile"
+
+		key="$(awk -F= '{ print $1 }' <<< $kv)"
+
+		if [[ -z "$key" ]]
+		then
+			crit "tyilnet/template" "Empty key in '$kv' while rendering $file?"
+		fi
+
+		value="$(awk -F= '{ print $NF }' <<< $kv)"
+
+		if [[ -z "$value" ]]
+		then
+			crit "tyilnet/template" "Empty key in '$kv' while rendering $file?"
+		fi
+
+		printf 's@${%s}@%s@g\n' "$key" "$value" >> "$sedfile"
+	done
+
+	sed -f "$sedfile" "$file"
+}
+
+# Create a temporary directory. Similar to tempfile, but you'll get a directory
+# instead.
+tmpdir() {
+	local dir
+
+	dir="$(mktemp -d)"
+
+	# Ensure the file was created succesfully
+	if [[ ! -d "$dir" ]]
+	then
+		die "tyilnet/tmpdir" "Failed to create a temporary directory at $dir"
+	fi
+
+	debug "tyilnet/tmpdir" "Temporary file created at $dir"
+
+	printf "%s" "$dir"
+}
+
+# Create a temporary file. In usage, this is no different from mktemp itself,
+# however, it will apply additional checks to ensure everything is going
+# correctly, and the files will be cleaned up automatically at the end.
+tmpfile() {
+	local file
+
+	file="$(mktemp)"
+
+	# Ensure the file was created succesfully
+	if [[ ! -f "$file" ]]
+	then
+		die "tyilnet/tmpfile" "Failed to create a temporary file at $file"
+	fi
+
+	debug "tyilnet/tmpfile" "Temporary file created at $file"
+
+	printf "%s" "$file"
+}
-- 
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