⏰ ⛔ cron-site-blocker

Note: This is a tiny workflow that I use daily for productivity.

A Node.js script that blocks and unblocks selected websites (resp. hosts), e.g. youtube.com, reddit.com.

In combination with a CRON job, it can be used to block access to selected websites in a given time frame on daily basis.

Configuration

Open editHosts.js and change the BLOCKED_HOSTS_LIST variable to the list of websites you want to block. E.g.

const BLOCKED_HOSTS_LIST = ["youtube.com", "reddit.com"];

Manual usage

To block the configured websites (hosts) manually, run:

node editHosts.js add

To unblock the configured websites (hosts) manually, run:

node editHosts.js remove

CRON job

To block/unblock the configured websites (hosts) automatically, you need to create a CRON job.

Here's a config that blocks BLOCKED_HOSTS_LIST every week day at 9:00 AM until 4:00 PM.

Open crontab with sudo crontab -e

Add the following lines to the file:

0 9 * * 1-5 sudo /usr/local/bin/node /path/to/cron-site-blocker/editHosts.js add >> /path/to/cron-site-blocker/cron.log 2>&1
0 16 * * 1-5 sudo /usr/local/bin/node /path/to/cron-site-blocker/editHosts.js remove >> /path/to/cron-site-blocker/cron.log 2>&1

Replace /path/to/cron-site-blocker with the path to the cron-site-blocker directory.

Since we're editing the hosts file, we need to run the script as root. We already have the sudo prefix in the cron job, but we also need to allow the passwordless sudo access.

To do this, run sudo visudo and add the following line to the file:

your-user-name ALL=(ALL) NOPASSWD: /usr/local/bin/node /path/to/cron-site-blocker/editHosts.js add
your-user-name ALL=(ALL) NOPASSWD: /usr/local/bin/node /path/to/cron-site-blocker/editHosts.js remove

Test the permissions by running

sudo /usr/local/bin/node /Users/jankoritak/Documents/Work/Personal/cron-site-blocker/editHosts.js add

and make sure /etc/hosts has been edited with your BLOCKED_HOSTS_LIST.

Check if the job is working by running crontab -l and checking if the jobs are listed.

🤓 Enjoy a productive workday!

Permissions

If you're on MacOS, you may need to add the script to access the file system via Security & Permissions -> Full Disc Access.

Debugging

Using CRON?

1. Make sure the CRON job is working by running crontab -l and checking if the jobs are listed.
2. Check the log file for errors.

Using the script manually?

1. Check the log file for errors.