Clearing Cloudflare and Nginx caches with Ansible

Since being DDoS continuously earlier this year, I've set up extra caching in front of my site. Originally I just had Nginx's proxy cache, but that topped out around 100 Mbps of continuous bandwidth and maybe 5-10,000 requests per second on my little DigitalOcean VPS.

So then I added Cloudflare's proxy caching service on top, and now I've been able to handle months with 5-10 TB of traffic (with multiple spikes of hundreds of mbps per second).

That's great, but caching comes with a tradeoff—any time I post a new article, update an old one, or a post receives a comment, it can take anywhere between 10-30 minutes before that change is reflected for end users.

I used to use Varnish, and with Varnish, you could configure cache purges directly from Drupal, so if any operation occurred that would invalidate cached content, Drupal could easily purge just that content from Varnish's cache.

You can't buy a Raspberry Pi right now

...or at least, not without a lot of patience or a fat wallet.

Scalping Prices of the Raspberry Pi on eBay

But why? And are there any signs Raspberry Pis will become available to the general public again soon?

To be clear, I'm speaking of the mainstream SBC Raspberry Pis, like the Pi 4 model B, the Compute Module 4, the Pi Zero 2 W, and even in many cases the Pi 400. The Pico and Pico W are both readily available, at least in most markets where I've looked (local shortages always exist, but typically not for months or years like with full-size Pis).

Homelab Pi Rack upgrade, just in time for AnsibleFest 2022

AnsibleFest is fast approaching, and this year it'll finally be back in person, in Chicago. Since that's a short jaunt from St. Louis, I'll be headed up to talk about my Homelab this year!

More specifically, I'll be giving a talk titled Ansible for the Homelab, and I'll walk through how I have at least part of my sprawling homelab environment automated using Ansible.

Raspberry Pi Rack Pro by UCTRONICS

BliKVM PCIe puts a computer in your computer

BliKVM PCIe with Raspberry Pi CM4 running PiKVM

This is the BliKVM PCIe, a full computer on a PCI Express card. This is an IP KVM (Internet Protocol Keyboard-Video-Mouse) that can be put inside another computer or server.

Most server motherboards already have remote 'lights-out' management functionality built in. Most frequently this is referred to as IPMI (Intelligent Platform Management Interface, but Dell calls it iDRAC, and HPE calls it ILO.

Short is good

I watched TheOdd1sOut's How to Find Inspiration1 and remembered the most important lesson I learned from my high school English teacher:

Short is good. Short is hard.

The teacher2 didn't exactly put it like that. But he harped on something nobody else did: writing concisely.

Every week we would read a work of American literature. And every Friday we'd turn in a one-pager encapsulating our knowledge of the book. I was an odd duck for how much I enjoyed the game: no playing with margins or font sizes. I had to cram an entire book into one page, double-spaced, with 1" margins, a title line, and a byline.

I remember spending Thursday nights honing my text, usually down to around 500 words. We would get a slight bonus for conveying more with fewer words.

That's surprisingly difficult for teenagers conditioned to churn out a specific word count. TheOdd1sOut commiserates: