Year: 2019

How to disable IPv6 on CentOS / RHEL 7

Sometimes I miss the good old days …

Recently, I had an issue with one of the servers, where a bunch of services were attaching to IPv6 ports instead of the IPv4 ones. Rather than editing the configuration of each of these services, I wanted to simply disabled IPv6 on the machine.

In the old good days, things like these were easily done via the sysctl. I surely tried that option too, but it wasn’t enough. Turns out, the proper way these days is to do this via Grub, as per this blog post:

  1. Vim /etc/default/grub file
  2. Change: GRUB_CMDLINE_LINUX=”ipv6.disable=1 crashkernel=auto rhgb quiet”
  3. Regenerate and overwrite Grub config with: grub2-mkconfig -o /boot/grub2/grub.cfg
  4. Reboot.

That sounds a bit too excessive. But then again a reboot is also required for the proper disabling of SELinux, so I guess its’ fine.

Chrome Extensions: PHP Console and JavaScript Errors Notifier

Here are a couple of handy Google Chrome extensions that I came across the other day.

PHP Console

PHP Console can display PHP errors and var dumps in the Google Chrome Developer Console and notification popups. It can also execute PHP code remotely, with the help of this server side library.

JavaScript Errors Notifier

JavaScript Errors Notifier lets you know of any JavaScript errors either with an icon highlight, or with a popup window. This makes things a lot easier to notice.

You Don’t Need jQuery

You Don’t Need jQuery is a GitHub repository with a collection of code snippets that show how to do the most common jQuery bits in native JavaScript. The collection covers a whole range of subjects, like:

  • Query selector
  • CSS and style
  • DOM manipulation
  • AJAX
  • Events
  • Promises
  • Animations
  • … and more.

All examples should work just fine in all modern browsers.

Additionally, have a look at the You Might Not Need jQuery website.