[enh] systemd help with dynamic variables

conf/systemd.service

@@ -7,7 +7,7 @@ Type=simple
 User=ztncui
 Group=ztncui
 Environment="PATH=__PATH__"
-WorkingDirectory=__FINAL_PATH__/src/
+WorkingDirectory=__FINALPATH__/src/
 ExecStart=__NODEJS_PATH__/npm start
 
 [Install]

scripts/_common.sh

@@ -32,6 +32,67 @@ exec_as() {
   fi
 }
 
+# Create a dedicated systemd config
+#
+# usage: ynh_add_systemd_config [--service=service] [--template=template]  [--others_var="list of others variables to replace"]
+# | arg: -s, --service - Service name (optional, $app by default)
+# | arg: -t, --template - Name of template file (optional, this is 'systemd' by default, meaning ./conf/systemd.service will be used as template)
+# | arg: -v, --others_var - List of others variables to replace separated by a space. For example: 'var_1 var_2 ...'
+#
+# This will use the template ../conf/<templatename>.service
+# to generate a systemd config, by replacing the following keywords
+# with global variables that should be defined before calling
+# this helper :
+#
+#   __APP__       by  $app
+#   __FINALPATH__ by  $final_path
+#
+# And dynamic variables (from the last example) :
+#   __VAR_1__    by $var_1
+#   __VAR_2__    by $var_2
+#
+# Requires YunoHost version 2.7.2 or higher.
+ynh_add_systemd_config_vars () {
+	# Declare an array to define the options of this helper.
+	local legacy_args=stv
+	declare -Ar args_array=( [s]=service= [t]=template= [v]=others_var= )
+	local service
+	local template
+	local others_var
+	# Manage arguments with getopts
+	ynh_handle_getopts_args "$@"
+	service="${service:-$app}"
+	template="${template:-systemd.service}"
+	others_var="${others_var:-}"
+
+	finalsystemdconf="/etc/systemd/system/$service.service"
+	ynh_backup_if_checksum_is_different --file="$finalsystemdconf"
+	cp ../conf/$template "$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 --match_string="__FINALPATH__" --replace_string="$final_path" --target_file="$finalsystemdconf"
+	fi
+	if test -n "${app:-}"; then
+		ynh_replace_string --match_string="__APP__" --replace_string="$app" --target_file="$finalsystemdconf"
+	fi
+
+	# Replace all other variables given as arguments
+	for var_to_replace in $others_var
+	do
+		# ${var_to_replace^^} make the content of the variable on upper-cases
+		# ${!var_to_replace} get the content of the variable named $var_to_replace
+		ynh_replace_string --match_string="__${var_to_replace^^}__" --replace_string="${!var_to_replace}" --target_file="$finalsystemdconf"
+	done
+
+	ynh_store_file_checksum --file="$finalsystemdconf"
+
+	chown root: "$finalsystemdconf"
+	systemctl enable $service
+	systemctl daemon-reload
+}
+
 #=================================================
 # FUTURE OFFICIAL HELPERS
 #=================================================

scripts/install

@@ -211,13 +211,8 @@ ynh_script_progression --message="Configuring a systemd service..." --time --wei
 ###		- As well as the section "RESTORE SYSTEMD" in the restore script
 ###		- And the section "SETUP SYSTEMD" in the upgrade script
 
-# Set the systemd service settings
-ynh_replace_string "__PATH__" "$PATH" "../conf/systemd.service"
-ynh_replace_string "__NODEJS_PATH__" "$nodejs_path" "../conf/systemd.service"
-ynh_replace_string "__FINAL_PATH__" "$final_path" "../conf/systemd.service"
-
 # Create a dedicated systemd config
-ynh_add_systemd_config
+ynh_add_systemd_config_vars --others_var="path nodejs_path"
 
 #=================================================
 # GENERIC FINALIZATION

scripts/upgrade

@@ -183,13 +183,8 @@ ynh_use_logrotate --non-append
 #=================================================
 ynh_script_progression --message="Upgrading systemd configuration..." --time --weight=1
 
-# Set the systemd service settings
-ynh_replace_string "__PATH__" "$PATH" "../conf/systemd.service"
-ynh_replace_string "__NODEJS_PATH__" "$nodejs_path" "../conf/systemd.service"
-ynh_replace_string "__FINAL_PATH__" "$final_path" "../conf/systemd.service"
-
 # Create a dedicated systemd config
-ynh_add_systemd_config
+ynh_add_systemd_config_vars --others_var="path nodejs_path"
 
 #=================================================
 # GENERIC FINALIZATION