Run some tasks periodically from the main process.

This reduces reliance on crontab jobs.

lib/www/server/periodic-tasks/index.js

@@ -0,0 +1,38 @@
+const tasks = require('./tasks');
+const { ALERT, ERROR, WARNING, NOTICE, INFO, DEBUG } = require('DOUGAL_ROOT/debug')(__filename);
+
+function init () {
+	const iids = [];
+
+	function start () {
+		INFO("Initialising %d periodic tasks", tasks.length);
+		for (let t of tasks) {
+			const iid = setInterval(t.task, t.timeout);
+			iids.push(iid);
+		}
+		return iids;
+	};
+
+	function stop () {
+		INFO("Stopping %d periodic tasks", iids.length);
+		for (let iid of iids) {
+			clearInterval(iid);
+		}
+	}
+
+	async function cleanup () {
+		stop();
+		DEBUG("Cleaning up %d periodic tasks", tasks.length);
+		for (let t of tasks) {
+			if (t.cleanup) {
+				await t.cleanup();
+			}
+		}
+	}
+
+	return { start, stop, cleanup, iids };
+}
+
+module.exports = {
+	init
+};