add example to run owncloud along with Kopano (#211)

* add example to run owncloud along with Kopano
* move ownloud files into dedicated folder
* add readme
* add script for ldap auto configuration

owncloud/owncloud.sh

@@ -0,0 +1,96 @@
+#!/bin/bash
+
+set -euo pipefail
+IFS=$'\n\t'
+
+if ! command -v reg > /dev/null; then
+	echo "Please install reg in order to run this script."
+	exit 1
+fi
+
+if [ ! -e ../.env ]; then
+	echo "please run setup.sh first"
+	exit 1
+fi
+
+# this is a kind of ugly hack to be able to source the env file
+# this is sadly needed since postfix in https://github.com/tomav/docker-mailserver/ cannot deal with quoted values
+tmpfile=$(mktemp /tmp/kopano-docker-env.XXXXXX)
+cp ../.env "$tmpfile"
+sed -i '/LDAP_QUERY_FILTER/s/^/#/g' "$tmpfile"
+sed -i '/SASLAUTHD_LDAP_FILTER/s/^/#/g' "$tmpfile"
+# shellcheck disable=SC1090
+source "$tmpfile"
+
+fqdn_to_dn() {
+	printf 'dc=%s' "$1" | sed -E 's/\./,dc=/g'
+}
+
+random_string() {
+	hexdump -n 16 -v -e '/1 "%02X"' /dev/urandom
+}
+
+docker_tag_search () {
+	image="$1"
+	results=$(reg tags "$image" 2> /dev/null)
+	echo "$results" | xargs -n1 | sort --version-sort -ru
+}
+
+# function from https://stackoverflow.com/a/42790579/4754613
+selectWithDefault() {
+
+	local item i=0 numItems=$#
+
+	# Print numbered menu items, based on the arguments passed.
+	for item; do         # Short for: for item in "$@"; do
+		printf '%s\n' "$((++i))) $item"
+	done >&2 # Print to stderr, as `select` does.
+
+	# Prompt the user for the index of the desired item.
+	while :; do
+		printf %s "${PS3-#? }" >&2 # Print the prompt string to stderr, as `select` does.
+		read -r index
+		# Make sure that the input is either empty or that a valid index was entered.
+		[[ -z $index ]] && break  # empty input
+		(( index >= 1 && index <= numItems )) 2>/dev/null || { echo "Invalid selection. Please try again." >&2; continue; }
+		break
+	done
+
+	# Output the selected item, if any.
+	[[ -n $index ]] && printf %s "${@: index:1}"
+}
+
+update_env_file () {
+	varname="$1"
+	varvalue="$2"
+	if ! grep -q "$varname" ../.env; then
+		echo "$varname=$varvalue" >> ../.env
+	else
+		sed -i "/$varname/c $varname=$varvalue" ../.env
+	fi
+}
+
+tag_question () {
+	containername="$1"
+	value_default="$2"
+	description="$3"
+	echo "Which tag do you want to use for $description? [$value_default]"
+	echo "Available tags in $containername: "
+	set +e # do not exit when new_value is empty
+	# shellcheck disable=SC2046
+	new_value=$(selectWithDefault $(docker_tag_search "$containername"))
+	set -e
+	return_value=${new_value:-$value_default}
+}
+
+tag_question owncloud/server "${OWNCLOUD_VERSION:-latest}" "Owncloud"
+update_env_file OWNCLOUD_VERSION "$return_value"
+update_env_file OWNCLOUD_DB_USERNAME owncloud
+update_env_file OWNCLOUD_DB_PASSWORD "$(random_string)"
+update_env_file OWNCLOUD_ADMIN_USERNAME admin
+update_env_file OWNCLOUD_ADMIN_PASSWORD "$(random_string)"
+update_env_file MARIADB_ROOT_PASSWORD "$(random_string)"
+
+if [ -e "$tmpfile" ]; then
+	rm "$tmpfile"
+fi