New Node-Job-Scheduler (thombergs#216)

Author: ajibade3210

nodejs/job-scheduler/demo.csv

@@ -0,0 +1,6 @@
+2022-09-01T23:52:45.356Z, 6.6314544677734375, 11%
+2022-09-01T23:53:00.489Z, 6.702445983886719, 13%
+2022-09-01T23:53:15.609Z, 6.74859619140625, 14%
+2022-09-01T23:53:30.727Z, 6.795112609863281, 11%
+2022-09-01T23:53:45.817Z, 6.841529846191406, 11%
+2022-09-01T23:54:00.899Z, 6.8905181884765625, 11%

nodejs/job-scheduler/example1.js

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+// Scheduling a simple task with node cron.
+
+const cron = require("node-cron");
+const express = require("express");
+
+const app = express();
+
+cron.schedule("*/15 * * * * *", function () {
+  console.log("---------------------");
+  console.log("running a task every 10 second");
+  //replace with any task
+});
+
+app.listen(3000);
+
+/*
+* Run the script: `node example1.js`
+* To log on application
+* at scheduled time
+*/

nodejs/job-scheduler/example2.js

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+const express = require("express");
+const cron = require("node-cron");
+const nodemailer = require("nodemailer");
+app = express();
+
+//send email after 1 minute
+cron.schedule("1 * * * *", function () {
+  mailService();
+});
+
+function mailService() {
+  let mailTransporter = nodemailer.createTransport({
+    service: "gmail",
+    auth: {
+      user: "<your-email>@gmail.com",
+      // use generated app password for gmail
+      pass: "***********",
+    },
+  });
+
+  // setting credentials
+  let mailDetails = {
+    from: "<your-email>@gmail.com",
+    to: "<user-email>@gmail.com",
+    subject: "Test Mail using Cron Job",
+    text: "Node.js Cron Job Email Demo Test from Reflectoring Blog",
+  };
+
+  // sending email
+  mailTransporter.sendMail(mailDetails, function (err, data) {
+    if (err) {
+      console.log("error occurred", err.message);
+    } else {
+      console.log("---------------------");
+      console.log("email sent successfully");
+    }
+  });
+}
+
+app.listen(3000, () => {
+  console.log("application listening.....");
+});
+
+/*
+ * Run the script: `node example2.js`
+ * To send E-mail
+ * at scheduled time
+ */

nodejs/job-scheduler/example3.js

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+// Writing to a log file
+
+// Importing required packages
+const process = require("process");
+const fs = require("fs");
+const os = require("os");
+const cron = require("node-cron");
+const express = require("express");
+
+app = express();
+
+// setting a cron job for every 15 seconds
+cron.schedule("*/15 * * * * *", function () {
+  let heap = process.memoryUsage().heapUsed / 1024 / 1024;
+  let date = new Date().toISOString();
+  const freeMemory = Math.round((os.freemem() * 100) / os.totalmem()) + "%";
+
+  //          date | heap used | free memory
+  let csv = `${date}, ${heap}, ${freeMemory}\n`;
+
+  // storing log In .csv file
+  fs.appendFile("demo.csv", csv, function (err) {
+    if (err) throw err;
+    console.log("server details logged!");
+  });
+});
+
+app.listen(3000, () => {
+  console.log("application listening.....");
+});
+
+/*
+* Run the script: `node example3.js`
+* To generate logstatus.txt file
+* at scheduled time
+*/

nodejs/job-scheduler/example4.js

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+// Deleting / Refreshing A log file.
+const express = require("express");
+const cron = require("node-cron");
+const fs = require("fs");
+
+app = express();
+
+// remove the demo.csv file every twenty-first day of the month.
+cron.schedule("0 0 25 * *", function () {
+  console.log("---------------------");
+  console.log("deleting logged status");
+  fs.unlink("./demo.csv", err => {
+    if (err) throw err;
+    console.log("deleted successfully");
+  });
+});
+
+app.listen(3000, () => {
+  console.log("application listening.....");
+});
+
+/*
+* Run the script: `node example4.js`
+* To delete demo.csv file
+* at scheduled time
+*/

nodejs/job-scheduler/package.json

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+{
+  "name": "new-folder-(3)",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "nodemon index.js"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "node-cron": "^3.0.2",
+    "node-mailer": "^0.1.1"
+  }
+}