Blog server upgrade to CentOS 8
Saturday, December 7. 2019
Since the inception of this blog back in January 2013, my weapon-of-choice has been CentOS Linux. When looking at the release chart @ https://en.wikipedia.org/wiki/CentOS#Latest_version_information it becomes obvious this is the 3rd major version of CentOS I'm running my blog on. In 2013 only version 6 was available, I must have upgraded into version 7 during 2014, and now 2019 I'm running on version 8. Given how RedHat and their organization(s) operate, the base Linux for my system is Fedora 28. See Fedora Project releases from https://fedoraproject.org/wiki/Releases.
The only motivation for me to upgrade is technology. RHEL/CentOS almost never upgrade their component versions. They do back-port any security patches even if authors of the original ones give up on their obsoleted stuff. RedHat does not. For people loving things how they are, that's a good thing. For people like me, its not that good.
Absolutely necessary things I had earlier, but lost and again have:
- HTTP/2
- For how and why this differs from HTTP/1.1 everybody else is still using, dive into Mr. Curl's book http2 explained. Its freely available @ https://http2-explained.haxx.se/content/en/
- TLS 1.3
- TLS versions 1 and 1.1 have been obsoleted. That leaves TLS 1.2 as the almost-only viable secure protocol.
- Obvious disclaimer for TLS 1.3: As of writing, it is still experimental. In reality not so much. Chrome and Firefox (among other platforms) support TLS 1.3 fully.
- Cloudflare's Head of Research Nick Sullivan is a known 1.3 enthusiast. Read his thoughts @ https://blog.cloudflare.com/rfc-8446-aka-tls-1-3/.
Other highlights:
- PHP 7.3
- My blog software runs on PHP. I upgraded 7.2, but am too scared to go for 7.4 yet.
- Native dual-stack IPv6/IPv4 networking. This is courtesy of my service provider.
- TLS 1.2 configured to not support any CBC-ciphers, for details see Why did TLS 1.3 drop AES-CBC? as an example
- Inspiration for this taken from Cipherli.st and Security/Server Side TLS on Mozilla wiki.
- Apologies for anybody using IE 11 on Windows Phone 8.1, or Safari versions 6-8 on iOS 6-9/OS X 10.9 or 10.10. You won't see this text as your devices/operating systems won't support my reasonably secure settings.
- For everybody else: Congratulations on having a decently secure device to do your Internet browsing with.
- tmux
- Terminal multiplexer, https://github.com/tmux/tmux/wiki
- Most of you just SSH into a server and be happy with it. I almost always run my sessions trough something that will keep my work safe if a disconnection occurs. To my surprise I keep bumping into sysadmins who don't either know about this or don't see this as a necessary approach.
- I've ran GNU Screen for over 25 years now. Not anymore. Uff!
- nftables (https://wiki.nftables.org/), courtesy of RHEL 8 / CentOS 8
- the new packet classification framework that replaces the existing {ip,ip6,arp,eb}_tables infrastructure
- I've ran IPchains / IPtables for 21 years now. Not anymore. Arf!
Qualsys report on my blog now:
Nice!
Next up: CentOS Stream.
A new attempt to allow change of software versions. This will effectively detach CentOS from RHEL and gear it towards Fedora. This enables CentOS to get newer software as a rolling release Linux-distro, but keep the changes not-so-aggressive.
I won't run this yet on my blog server. This is so new at this point, but I'll have it running on a devel-box.