diff --git a/scripts/_common.sh b/scripts/_common.sh
index dce035f..7d4f823 100644
--- a/scripts/_common.sh
+++ b/scripts/_common.sh
@@ -1,5 +1,19 @@
 #!/bin/bash
 
+
+# Execute a command as another user
+# usage: exec_as USER COMMAND [ARG ...]
+exec_as() {
+	local user=$1
+	shift 1
+
+	if [[ $user = $(whoami) ]]; then
+		eval "$@"
+	else
+		sudo --login --user="$user" "$@"
+	fi
+}
+
 #=================================================
 #
 # POSTGRES HELPERS
diff --git a/scripts/_future.sh b/scripts/_future.sh
new file mode 100644
index 0000000..82f255c
--- /dev/null
+++ b/scripts/_future.sh
@@ -0,0 +1,127 @@
+#!/bin/bash
+
+# needed to have "service_name" as an option
+# https://github.com/YunoHost/yunohost/commit/9c4ddcca39d9d6d92bd5f9a23978337e48d0a4e1
+ynh_add_systemd_config () {
+	local service_name="${1:-$app}"
+
+	finalsystemdconf="/etc/systemd/system/$service_name.service"
+	ynh_backup_if_checksum_is_different "$finalsystemdconf"
+	sudo cp ../conf/${2:-systemd.service} "$finalsystemdconf"
+
+	# To avoid a break by set -u, use a void substitution ${var:-}. If the variable is not set, it's simply set with an empty variable.
+	# Substitute in a nginx config file only if the variable is not empty
+	if test -n "${final_path:-}"; then
+		ynh_replace_string "__FINALPATH__" "$final_path" "$finalsystemdconf"
+	fi
+	if test -n "${app:-}"; then
+		ynh_replace_string "__APP__" "$app" "$finalsystemdconf"
+	fi
+	ynh_store_file_checksum "$finalsystemdconf"
+
+	sudo chown root: "$finalsystemdconf"
+	sudo systemctl enable $service_name
+	sudo systemctl daemon-reload
+}
+
+# needed to have "service_name" as an option
+# https://github.com/YunoHost/yunohost/commit/9c4ddcca39d9d6d92bd5f9a23978337e48d0a4e1
+ynh_remove_systemd_config () {
+	local service_name="${1:-$app}"
+
+	local finalsystemdconf="/etc/systemd/system/$service_name.service"
+	if [ -e "$finalsystemdconf" ]; then
+		sudo systemctl stop $service_name
+		sudo systemctl disable $service_name
+		ynh_secure_remove "$finalsystemdconf"
+		sudo systemctl daemon-reload
+	fi
+}
+
+
+# LOCAL ADDITION:
+# save file locally if not in the cache
+#
+# Download, check integrity, uncompress and patch the source from app.src
+ynh_setup_source () {
+    local dest_dir=$1
+    local src_id=${2:-app} # If the argument is not given, source_id equals "app"
+
+    # Load value from configuration file (see above for a small doc about this file
+    # format)
+    local src_url=$(grep 'SOURCE_URL=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
+    local src_sum=$(grep 'SOURCE_SUM=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
+    local src_sumprg=$(grep 'SOURCE_SUM_PRG=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
+    local src_format=$(grep 'SOURCE_FORMAT=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
+    local src_in_subdir=$(grep 'SOURCE_IN_SUBDIR=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
+    local src_filename=$(grep 'SOURCE_FILENAME=' "$YNH_CWD/../conf/${src_id}.src" | cut -d= -f2-)
+
+    # Default value
+    src_sumprg=${src_sumprg:-sha256sum}
+    src_in_subdir=${src_in_subdir:-true}
+    src_format=${src_format:-tar.gz}
+    src_format=$(echo "$src_format" | tr '[:upper:]' '[:lower:]')
+    if [ "$src_filename" = "" ] ; then
+        src_filename="${src_id}.${src_format}"
+    fi
+    local local_src="/var/cache/yunohost/ynh_setup_source/${YNH_APP_ID}/${src_filename}"
+
+    # if cache file exists and the checksum isn't good, download it again
+    # if not, just download the file
+
+    if test -e "$local_src"
+    then
+    	echo "${src_sum} ${local_src}" | ${src_sumprg} -c --status \
+        	|| wget -nv -O $local_src $src_url
+    else
+    	mkdir -p "/var/cache/yunohost/ynh_setup_source/${YNH_APP_ID}"
+    	wget -nv -O $local_src $src_url
+    fi
+    cp $local_src $src_filename
+
+    # Check the control sum
+    echo "${src_sum} ${src_filename}" | ${src_sumprg} -c --status \
+        || ynh_die "Corrupt source"
+
+    # Extract source into the app dir
+    mkdir -p "$dest_dir"
+    if [ "$src_format" = "zip" ]
+    then
+        # Zip format
+        # Using of a temp directory, because unzip doesn't manage --strip-components
+        if $src_in_subdir ; then
+            local tmp_dir=$(mktemp -d)
+            unzip -quo $src_filename -d "$tmp_dir"
+            cp -a $tmp_dir/*/. "$dest_dir"
+            ynh_secure_remove "$tmp_dir"
+        else
+            unzip -quo $src_filename -d "$dest_dir"
+        fi
+    else
+        local strip=""
+        if $src_in_subdir ; then
+            strip="--strip-components 1"
+        fi
+        if [[ "$src_format" =~ ^tar.gz|tar.bz2|tar.xz$ ]] ; then
+            tar -xf $src_filename -C "$dest_dir" $strip
+        else
+            ynh_die "Archive format unrecognized."
+        fi
+    fi
+
+    # Apply patches
+    if (( $(find $YNH_CWD/../sources/patches/ -type f -name "${src_id}-*.patch" 2> /dev/null | wc -l) > "0" )); then
+        local old_dir=$(pwd)
+        (cd "$dest_dir" \
+            && for p in $YNH_CWD/../sources/patches/${src_id}-*.patch; do \
+                patch -p1 < $p; done) \
+            || ynh_die "Unable to apply patches"
+        cd $old_dir
+    fi
+
+    # Add supplementary files
+    if test -e "$YNH_CWD/../sources/extra_files/${src_id}"; then
+        cp -a $YNH_CWD/../sources/extra_files/$src_id/. "$dest_dir"
+    fi
+}
+