Typescript migration:

* Refactoring of scheduler and jobs to use promises.
* Add "failed" state for tasks.

server/jobs/scheduler.ts

@@ -0,0 +1,126 @@
+import cron from "node-cron";
+import moment from "moment";
+
+import {config} from "../config";
+import Logger from "../logger";
+
+import MailQueueJob from "./MailQueueJob";
+import FixNodeFilenamesJob from "./FixNodeFilenamesJob";
+import NodeInformationRetrievalJob from "./NodeInformationRetrievalJob";
+import MonitoringMailsSendingJob from "./MonitoringMailsSendingJob";
+import OfflineNodesDeletionJob from "./OfflineNodesDeletionJob";
+
+export interface Job {
+    name: string,
+    description: string,
+
+    run(): Promise<void>,
+}
+
+export enum TaskState {
+    IDLE = "idle",
+    RUNNING = "running",
+    FAILED = "failed",
+}
+
+export class Task {
+    constructor(
+        public id: number,
+        public name: string,
+        public description: string,
+        public schedule: string,
+        public job: Job,
+        public runningSince: moment.Moment | null,
+        public lastRunStarted: moment.Moment | null,
+        public lastRunDuration: number | null,
+        public state: TaskState,
+        public enabled: true,
+    ) {}
+
+    run(): void {
+        if (this.runningSince || !this.enabled) {
+            // job is still running, skip execution
+            return;
+        }
+
+        this.runningSince = moment();
+        this.lastRunStarted = this.runningSince;
+        this.state = TaskState.RUNNING;
+
+        const done = (state: TaskState):void => {
+            const now = moment();
+            const duration = now.diff(this.runningSince || now);
+            Logger.tag('jobs').profile('[%sms]\t%s', duration, this.name);
+
+            this.runningSince = null;
+            this.lastRunDuration = duration;
+            this.state = state;
+        };
+
+        this.job.run().then(() => {
+            done(TaskState.IDLE);
+        }).catch((err: any) => {
+            Logger.tag('jobs').error("Job %s failed: %s", this.name, err);
+            done(TaskState.FAILED);
+        });
+    }
+}
+
+type Tasks = {[key: string]: Task};
+
+const tasks: Tasks = {};
+
+let taskId = 1;
+function nextTaskId(): number {
+    const id = taskId;
+    taskId += 1;
+    return id;
+}
+
+function schedule(expr: string, job: Job): void {
+    Logger.tag('jobs').info('Scheduling job: %s  %s', expr, job.name);
+
+    const id = nextTaskId();
+
+    const task = new Task(
+        id,
+        job.name,
+        job.description,
+        expr,
+        job,
+        null,
+        null,
+        null,
+        TaskState.IDLE,
+        true
+    );
+
+    cron.schedule(expr, task.run);
+
+    tasks['' + id] = task;
+}
+
+export function init() {
+    Logger.tag('jobs').info('Scheduling background jobs...');
+
+    try {
+        schedule('0 */1 * * * *', MailQueueJob);
+        schedule('15 */1 * * * *', FixNodeFilenamesJob);
+
+        if (config.client.monitoring.enabled) {
+            schedule('30 */15 * * * *', NodeInformationRetrievalJob);
+            schedule('45 */5 * * * *', MonitoringMailsSendingJob);
+            schedule('0 0 3 * * *', OfflineNodesDeletionJob); // every night at 3:00
+        }
+    }
+    catch (error) {
+        Logger.tag('jobs').error('Error during scheduling of background jobs:', error);
+        throw error;
+    }
+
+    Logger.tag('jobs').info('Scheduling of background jobs done.');
+}
+
+export function getTasks(): Tasks {
+    return tasks;
+}