I have a job with Nodejs that I want to do it each 30 minutes to scan the Database and Update Products Data in An Ecommerce API with my Nodejs Program, note that the Nodejs Program is serving an REST API (Backend) for a react js web application
So I searched for that and I found that I can do that with Nodejs Cron Library like "node-schedule" but I know that will be more interesting to do it with Linux Cron
var j = schedule.scheduleJob('42 * * * *', function(){
console.log('The answer to life, the universe, and everything!');
});
Is there any library that can let me add Cron jobs to Linux using Nodejs Or would I do it with "fs" only? so I will open the cron job file and add my command?
The command crontab which is part of Vixie Cron allows you to create, edit and delete per-user cron entries.
Or if you are running as the root user, which you should not be doing, you can drop cron files into /etc/cron.d
This is not always supported, and if you're running in a Docker type container environment it is doubtful that you have any cron at all. In that environment you'd want your running Nodejs to handle scheduled jobs for you. Or use some other kind of distributed scheduled work system.
You can put your cron job to a nodejs script. Then adding to the crontab can be done with cronbee module, via API:
import { cronbee } from 'cronbee'
await cronbee.ensure({
taskName: 'do smth',
taskRun: `node my-script`,
cron: '42 * * * *'
})
or you can ensure the cron job via CLI, if the module is installed globally or from npm scripts:
$ cronbee ensure mytasks.json
Related
I have a NodeJS app consisting of a REST API and an overnight maintenance (cron) job. Currently running on Debian Linux.
What is the best practice do Dockerize it?
I can use the official "node" Docker image, however that doesn't contain a crontab.
I can use the official "alpine" Docker image (and install NodeJS in it) however I lose the possibility of upgrading NodeJS with the easy of pulling a new version of the official image.
What is the best way to achieve this?
Solution #1
Use a node cron package. I added some code example from a real project. Every hour I scrape a website. You can set time and place your recurring task inside cron.schedule. You can use it a separate project or combine with your api code.
import { Scraper } from './controller/scraper.js';
import cron from 'node-cron'
cron.schedule('0 0 */1 * * *', () => {
console.log('running a task every hour');
const scraper = new Scraper()
const data = scraper.getData()
});
Solution #2
Docker official website doesn't advice running process managers with containers. But you can use if you need. I use pm2 as a process manager. It can be used for running an app for some intervals and it can restart your app if it crashes.
Links that will help you:
https://pm2.keymetrics.io/
https://pm2.keymetrics.io/docs/usage/docker-pm2-nodejs/
My use case:
Restart app if it crashes.
Run app.js file for each hour.
Use official nodejs docker image and build docker image with your code.
You need to run two containers, one for Rest API and other for cron job.
For cron job you dont need conrtab inside the docker image but schedule the image run on the host machine like below:
This will ensure to run docker image at required interval.
crontab -e
* */2 * * * docker run -it app/cron-image:v1
I run one of my node.js command using the following command:
pm2 start sample.js --cron "0 1 * * *" -- SAMP
But the problem is this program run twice. First one is when I execute the command and send one is at 1:00 AM(Which we want).
So my query is how can set the cron so that this program runs at only once (At 1:00 AM only).
My suggestion to you is to use crontab for this task. This is exactly what cron was designed for, and not what pm2 was designed for.
As the comment above states, the --cron option only specifies when the app should be restarted, --cron cannot be used to schedule the running of an app. In the cases where we need to run a node app on a specific time table and don't need all of the fancy pm2 capabilities of auto-restarting and clustering, we simply use crontab.
I have been trying to figure out how to use crontabs on my mac OS X I have a node script written that I would like to be able to execute in a scheduled manner. Here is the line I am using in my crontab file.
30 * * * * /usr/local/bin/node /Users/pmanca/Google Drive/JavaScript/code/Peter/marketing-tests/testBackup.js
It doesn't appear to be executing though. Can anyone see what I am doing wrong? Also is there another way on a mac or linux server to accomplish what I'm looking for? Also can you use the same line for a crontab job in linux as well(besides the file paths needing to change)?
You can use one of the two npm packages, cron or agenda
Both work on linux and OS X. Cron is best if your tasks are lightweight and you don't need your jobs to be persisted into db. Agenda uses mongodb for persistence.
You can configure a job in cron as:
var CronJob = require('cron').CronJob;
var job = new CronJob({
cronTime: '00 */30 * * * *',
onTick: function() {
/*
* Runs every 30 minutes, every hour, every day, all week
*/
},
start: false,
timeZone: 'America/Los_Angeles'
});
job.start();
To run in background on server you can run it with forever
Remember cron has an additional 6th place to the left for seconds. Otherwise the syntax is same.
By default cron process doesn't have the required permission to access the disk in macos. So, you should allow full access disk to cron process. For this one, add /usr/sbin/cron to your allowed full disk access process under Security & Privacy. Further information can be seen in How to Fix Cron Permission Issues in MacOS Catalina & Mojave
I need to run my nodejs script for every second ,Similar to PHP cron jobs. I have tried some nodejs cron libraries like https://github.com/ncb000gt/node-cron but the issue was first run should be manual i:e I have to run the file with cron script for first time manually.
But in php cron jobs, they run by the server so if the apache server running script will automatically start and even if the script return an error for a cycle then script will run again from the beginning from the next cycle
So is there any way to achieve this in nodejs ?
You have two options:
using Node as a daemon, with something like Supervisord to run your node-cron script. This alternative is wasteful on resources such as RAM because Node and Supervisord are running all the time.
using the system's crontab, you can run your script like calling Node on the command line, such as * * * * node /path/to/your/script.js. This alternative is highly efficient but lacks some control, like being able to log the output in case of an error, although you could just pipe the output to a file: node script.js > logfile
I'm trying to set up a node script to run as a cron job on Joyent. I can run arbitrary commands but node scripts to seem to execute. As an example:
# cron
# call a script every minute
# being specific about the location of node and the script to run
* * * * * /home/node/local/nodejs/bin/node /full/path/to/some-script.js
// node script at /full/path/to/some-script.js
var fs = require('fs');
fs.writeFile('/home/node/node-service/some-script.log', new Date.toString(), 'utf8');
What I expect to see after one minute is a file at /home/node/node-service/some-script.log with content like Mon Jan 21 2013 15:19:11 GMT-0600 but I see nothing. This is still the case even if the script is set to full read, write and execute permissions for all users and whether the crontab is set for the root or node users.
What am I missing?
Thanks
The fourth optional argument to writeFile is a callback to fire when the file system is done writing the file. You can use it to determine the error that is happening, as it's only argument is an error. Refer to the docs here.
It appears to be working now. I'm not sure what I changed that got it working. It may have been a permissions issue.