Create a Job Using R

A Saturn Cloud job is a computing environment set up to run recurring tasks. You can start a job in 3 ways:

1. on a schedule
2. manually by pressing start button
3. via an API

Setting up a job in Saturn Cloud is easy- Go to the Resources tab of Saturn Cloud and press New Job. But before discussing all the options in setting up the job resource, we will walk through an example code which we will be executing as job.

Example code

Saturn Cloud jobs and deployments need to load the code to run, and the easiest way to do so is with a git repository. Create a git repository on a service like GitHub–we’ll then tell the Saturn Cloud job to pull the latest version of the code each time the job starts. This is an example R script which we will be running as a job. In this script, we are printing a message in logs. You’ll want create one of your own more interesting script for your job. If you want to run a python script instead, see [the Saturn Cloud docs](https://saturncloud.io/docs/examples/python/production/jobs/#example-code.

Below is the example.R script that the job will be running. It is saved in the GitHub repo that our job will be pulling from:

library(logger)
log_info('Job is successfully running!')

Installations and Start Script

The startup command will run before the job does to set up in the environment. In our case the command will be to execute a single start script which installs the packages. This start up command is saved in Advanced Settings -> Start Script section. The startup command is Rscript setup.R, and the actual setup.R file contains:

install.packages('logger')

The setup.R file needs to be saved in the same git repository as example.R.

Create a job

To create a job for example.R script or any of your own script, first press the New Job button on the upper right corner of the Resources page.

Specify the following settings below. Note that the git settings need to be set after the resource is created.

• Command - Rscript path_to_your_repository/example.R. Here ‘path_to_your_repository’ refers to the path of your repository where file example.R is stored. Instead of Rscript, if you want to run an RMarkdown file, use RScript -e "rmarkdown::render('filename.Rmd')"
• Git Repositories - Select New Git Repository and add your repository here.
• Image - Set to saturn-rstudio image.
• Advanced Settings -> Start Script - Rscript setup.R

You are now set. To run your job manually press the green start button on the resource page of the job.

Running a Saturn Cloud job as an API

In addition to running the job on a button press or on a schedule, you can also run it as an API. This is useful if you want a different program to cause the job to start. To run the job created programmatically, you need:

• User Token - You can get your user token from the Settings page of Saturn Cloud.
• Job ID - It is the hexadecimal value in the URL of the job’s resource page: https://app.community.saturnenterprise.io/dash/resources/job/{job_id}.

Now using above parameters trigger the job via HTTP request sending system, like curl or Postman. The following is the code if you want to start the job using R.

library(httr)
user_token = "youusertoken"  # (don't save this directly in a file!)
job_id="yourjob id"
url=paste("https://app.community.saturnenterprise.io/api/jobs/",job_id,"/start",sep="")
POST(url, add_headers(Authorization=paste("Token ", user_token)))

Running a Saturn Cloud job on a Schedule

You can also run this job or any other job you created, on schedule. This will automate running a job on a fixed time. Check the box for field Run this job on a schedule and populate Scheduled Settings using cron syntax to meet the requirements of your task.