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_posts/2019-12-11-Cron.md

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+---
+layout: post
+title:  "I used cron for the first time"
+description: "And I didn't die"
+date:   2019-12-11 11:38:00
+categories: random
+redirect_from: 
+ - /post/cd9dj84kf0/
+ - /cd9dj84kf0/
+---
+
+
+[Cron](https://en.wikipedia.org/wiki/Cron) has always been one of those "scary sysadmin things" in my head. But today, I finally used it!
+
+## My need
+I have access to a private API that happens to clear it's users if they are inactive for too long. To solve this, I decided to add a small cron job to make an API call once per month. Basically a [keepalive](https://en.wikipedia.org/wiki/Keepalive).
+
+## How I set it up
+
+Adding a cron job to my laptop was very easy. First, I made a bash script for my api call (not needed, but I felt like doing it).
+
+```sh
+#! /bin/bash
+curl --include --header "Accept: application/xml" '<API Endpoint Here>' --user $1:$2
+```
+
+Then, by running `crontab -e` in my terminal, I just added a new line at the bottom of the file, discribing the task, and when it should be run.
+```cron
+# Edit this file to introduce tasks to be run by cron.
+# 
+# Each task to run has to be defined through a single line
+# indicating with different fields when the task will be run
+# and what command to run for the task
+# 
+# To define the time you can provide concrete values for
+# minute (m), hour (h), day of month (dom), month (mon),
+# and day of week (dow) or use '*' in these fields (for 'any').# 
+# Notice that tasks will be started based on the cron's system
+# daemon's notion of time and timezones.
+# 
+# Output of the crontab jobs (including errors) is sent through
+# email to the user the crontab file belongs to (unless redirected).
+# 
+# For example, you can run a backup of all your user accounts
+# at 5 a.m every week with:
+# 0 5 * * 1 tar -zcf /var/backups/home.tgz /home/
+# 
+# For more information see the manual pages of crontab(5) and cron(8)
+# 
+# m h  dom mon dow   command
+00 11 1 * * /usr/local/bin/api-keepalive.sh <username> <password>
+```
+
+This will run once per month, on the 1st, at 11:00.
+
+That's it! Stupidly simple, and I am no longer scared of cron