Igor Bubelov
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March 2021

Notes ยท Apr 2, 2021

Table of Contents

More Ansible

I continued moving my infrastructure to Ansible and the more I use this tool, the more I like it. It makes it easy to manage my servers, and it also forces me to look on Linux from a slightly different angle. This month, I moved my static websites to a separate host fully managed by Ansible and it was pretty straightforward. I also wanted to use Nextcloud without Docker, and it seemed a bit overwhelming at first, but the whole process turned up to be quite simple. Ansible has a concept of roles, which are useful for repetitive tasks. I created a special Ansible role for setting up dynamic fan control on my Raspberry Pi based servers.

Lightning Wallets and Full Nodes

Every Bitcoin user is supposed to have their own full copy of a blockchain. Unfortunately, it takes more than 400 GB and this number goes up every 10 minutes. Most smartphones and even laptops don’t have enough free space to store blockchain, which is a big problem. The first attempted solution is called SPV (BIP 37), short for Simple Payment Verification. SPV-enabled Bitcoin wallets don’t need to store a full copy of blockchain, and they often require less than a few hundreds of megabytes.

SPV is not an ideal protocol and it has some serious flaws. Even if it was flawless, having fewer copies of blockchain weakens the whole Bitcoin network. You should totally run your own full node if you’re in a position to do so. For other situations, it’s nice to have a way of using Bitcoin without setting up a full node. Being able to install a Bitcoin wallet by a single tap on your phone screen certainly helps the adoption.

I’ve been playing with RaspiBlitz recently, mostly because I wanted to evaluate the current state of Lightning Network. It’s been a pleasure, so far, but it requires a bit of technical knowledge and a few hundred dollars. This doesn’t look like something with an explosive potential for mass adoption, which led me to the following question: is it possible to have a Lightning wallet without a full node? I’d love to have such an app on my phone.

It turned up, there are a few ways to run a Lightning wallet without having a full copy of blockchain. The most interesting one is called Neutrino, or BIP 157 / BIP 158. It can also be used by Bitcoin wallets and it supposed to replace SPV. This means that we can totally have a reasonably secure and private Lightning wallets in the form of simple mobile apps with no extra costs or manual setup. Looks like the future of Lightning Network is bright.

Apache2

I don’t have a lot of experience with web servers, which didn’t prevent me from publishing a few posts on this topic, of course. I always used Nginx wrapped in a container, so I decided to try “bare” Apache2. Containers are nice, but they don’t make much sense for my personal Nextcloud server. The “isolation” benefits are gone since there is nothing to isolate it from.

I guess I had some false pre-suppositions regarding Apache2. I expected it to be ancient, slow, and hard to set up. Nothing of that is actually true, Apache2 is a very easy to use, transparent and well-documented webserver. The documentation is pleasure to read and Ubuntu integration is excellent. I used to rely on reverse proxies such as Traefik for managing my HTTPS certificates, but it’s even easier on “bare” system. The certbot package is just one apt/snap install away and it integrates with systemd timers for automatic renewals.

Book: Studies in Pessimism by Arthur Schopenhauer

I first heard about Schopenhauer in college. He seemed like an interesting philosopher, but I’ve never read his books. I don’t really remember how I got the link to this audiobook a couple of weeks ago, but I’m glad I’ve got it. There is something deep in his thoughts that rings true to our nature. I get why some people see him as a king of pessimism, but don’t let this playful mockery devalue the arguments Schopenhauer makes.

I’m casually aware of the idea of will as a separate and almighty entity:

A man can do as he will, but not will as he will - Arthur Schopenhauer

This particular book is a loose set of ramblings on different topics, most of them are pretty amusing. The part about women didn’t age well, though.

Text version: https://archive.org/details/cu31924029073579

Audio version: https://www.youtube.com/watch?v=-xPqPu4KT4o

Headset: Jabra Evolve 30 II

I’ve been doing some podcasting in the last few months and it motivated me to buy a mic. I don’t know much about mics and I’m not ready to waste a lot of money on a thing that I might not need, so I decided to start with a simple headset from Jabra and I’m pleased with a headset I’ve got. It greatly improved the quality of my voice recording and the headphones themselves are also great. They don’t cause pain in my ears even if I use them for a few hours. Most of other headphones do, and I’m not sure if I’m alone here or it’s a common thing.

Game: Europa Universalis IV

This game is extremely addictive, and I had a misfortune to touch it again. What surprised me is the fact that many game elements were significantly reworked since I played it last time about a year ago. That’s pretty unexpected for a game published around 2014. The authors also introduced a subscription model and this thing is pure evil and a huge disappointment. I’m sure we’ll see some subscription-only content and other kinds of dark patterns pretty soon.