Logbook

hello world, an annotated history (gist)

See https://gist.github.com/vielmetti/3360df282d7cbadf579a09ebb74d536a for an annotated list of "Hello World" style one-liners using a variety of tools, sorted by the date that the code is available.

I'll come up with a better place to publish this - it turns out that Typepad is not the best spot to post code.

self-hosted monitoring with Uptime Kuma

"Uptime Kuma" is a self-hosted monitoring tool, which has a very nice design and which fits in a small memory and compute footprint. This makes it a good fit for household and homelab operations.

https://uptime.kuma.pet

I'm still figuring out a permanent home on my home network / tailnet for it, but for the moment I have it running on my laptop which means I get to see some relatively more frequent failure conditions as the network goes on and offline when I power down or move between locations.

"Uptime Kuma" can do the usual sorts of things you might want to do with a simple network monitor, including ping, DNS lookup, HTTP fetch, very simple pattern match on web pages, and the like. It won't let you run an arbitrary command on a schedule though, and the web site pattern matching happens without any parsing of the HTML page, so some fancy setups might be hard.

I'm currently using it to monitor network infrastructure like my home router and a few ATT systems on the traceroute path to the rest of the Internet. A separate dashboard watches to see that my PiAware ADS-B airplane monitor is getting good data; it wasn't when I started watching things, so there was a weekend side-quest to move the receiver to get a better view of the sky.

I haven't set up any active alerts or alarms yet. There are feeds into a bunch of systems including SMS, Home Assistant, Telegram, and Slack.

One of the virtues of Uptime Kuma is that the development community is very mindful of resource consumption, and things like memory leaks or inefficiencies that would prevent it from running on an old Pi or a free tier on a container service like https://fly.io have been fixed.

An alternative to this if you have more resources to throw at the task (and more features with it) is OneUptime which is also available as a hosted system. The open source version of OneUptime wants 8 cores (!) to run on, so that kind of ruled it out for my uses.

https://github.com/OneUptime/oneuptime

Another alternative is HealthChecks which drives the telemetry and monitoring with a Python and Django application. This too has a hosted free tier of service or can be run in your homelab self-hosted.

https://healthchecks.io

In truth my homelab setup (which is mostly a pile of Raspberry Pi systems) doesn't have much downtime, and even if it did the consequences would be minimal. Still it's nice to get a quick overview when everything is working, and some speedy look at where to go next if something isn't quite right.

privacy-preserving telemetry isn't real

I don't actually believe that privacy-preserving telemetry is even a thing that can be real. Telemetry is designed to leak information about what's happening on a system, and by doing that you inevitably leak bits of privacy-adjacent material, and if you accumulate enough bits you get reidentification of previously "anonymous" information.

This is in reference to our favorite elephant in the room's favorite hat, see https://discussion.fedoraproject.org/t/f40-change-request-privacy-preserving-telemetry-for-fedora-workstation-system-wide/85320/1 for the relevant discussion bits.

My favorite old-school reading on the topic of reidentification is the 33 Bits blog https://33bits.wordpress.com from Arvind Narayanan.

Now this is the right way to do opt-in telemetry:

https://dmesgd.nycbug.org/index.cgi?do=index

Launched in 2004, dmesgd aims to provide a user-submitted repository of searchable *BSD dmesgs. The dmesg(8) command displays the system message buffer's content, and during boot a copy is saved to /var/run/dmesg.boot. This buffer contains the operating system release, name and version, a list of devices identified, plus a whole host of other useful information. We hope others find this resource useful and further contribute to its growth.

Not only is this telemetry opt-in, but it's also public, and the contributors can edit their contributions as appropriate to elide inconvenient information or add more annotations to the system details. With a nearly 20 year track record, this is an important collection.

writing in a personal wiki

I prefer writing in a personal wiki to pretty much anything other kind of writing. There's a certain amount of producing original words, a lot more editing so that you get the right words or enough words, and a peculiar bit of wiki gardening where you're trying to shape the whole thing one edit at a time.

My favorite wiki to date is Obsidian. I've produced about 3300 pages in my word-hoard there, about 300000 words in 2 years.

I told myself that at 10000 pages I'd start over.

via https://hachyderm.io/@w8emv/110676439276925705