Paul Carleton's blog

BeanCat

A black cat accountantIn about the 17th iteration of me working on a personal finance app, I'm setting up a plaid integration. The tooling setup roughly looks like: * Beancount as the resulting data format * Fava as the view * beancount-import to help automatically categorizing * Plaid to download transaction data (they support

Rust: What to pick for the Error type when writing your own Result type

The Result type [https://doc.rust-lang.org/std/io/type.Result.html] in rust is great! Combined with the ? operator [https://doc.rust-lang.org/edition-guide/rust-2018/error-handling-and-panics/the-question-mark-operator-for-easier-error-handling.html] , it makes error handling much more concise than other languages. Consider ? vs: * Go: if err != nil { return nil, err } * Java:try

Observable + bean-count

Two of my favorite tools lately are Observable (observablehq.com) (a long time favorite for quickly prototyping javascript and creating interactive visualizations) and bean-count (a more recent addition for doing "hobbyist double entry accounting" (a special form of "fun")). fava is a great open source web UI for bean-count that

Learning Mutability in Rust

I'm writing Rust for the first time in awhile, and I ran into an issue with mutability, that I figured I'd write up. The thing I was trying to do was have a Client that creates an XML response body, and then makes a request to a server. There are

How to MITM yourself with socat with TLS

I was learning about OFX api's (what Quicken uses to pull your transaction info) for a personal project, and I kept getting 400 Bad Request errors. I wanted to see what the requests I was making with curl looked like to the server. Then I wanted to compare what requests

Skincare: An ignorant guy's attempt to learn more part 2 - Dermatologists and the microbiome

In the first post [https://pcarleton.com/2021/03/01/a-guys-guide-to-skin-care/] in this series, I laid out the following things to do: * See a dermatologist (but read below about things to keep in mind) * Try a product "diet" to see if less is more for your skin * Get some sunscreen

skincare

Skin care: an ignorant guy's attempt to learn more

Bernie Sanders was interviewed by Cosmopolitan [https://www.cosmopolitan.com/politics/a29255694/bernie-sanders-cosmopolitan-interview-election-immigration-gun-control-healthcare-young-women/] , and at the very end of the interview, they asked: > Jessica Pels: What’s your skincare routine? Bernie Sanders: Not much. Jessica Pels: Do you moisturize? Bernie Sanders: I put something on. I got something, the doctor

obseravable

Embedding Observable notebooks into a blog

This post is an Observable notebook! [https://observablehq.com/@pcarleton/blog-test] Follow that link to edit or fork it.

Do it Live! with ObservableHQ, a platform by the creator of D3.js

presentation by Paul Carleton [https://twitter.com/paulcarletonjr] from Stripe [https://stripe.com/jobs/search?l=mexico] for EventLoop [https://www.meetup.com/eventloop/] in Mexico City on September 4th 2019 Do it Live! with ObservableHQ, a platform by the creator of D3.jsAn Observable notebook by Paul Carleton.ObservablePaul

CLI for the Moon

After trudging through the grossness of trying to add to $PS1 from a script, I got to thinking it would be fun to have the phase of the moon on my shell prompt.

PS1: The shell prompt variable and the tricky parts about setting it

I wanted to add some information to the shell prompt from a script recently and learned some things about bash, PS1 and shell variables along the way. What is a shell prompt and why would I want to set it? The shell prompt is the chunk of text that comes

Telnet

An exchange I had a few months ago went something like this: > Me: Weird, my requests aren't getting through, but I can ping the server just fine. Coworker: I can't telnet to the port... the firewall is probably blocking your traffic. Me (to myself): 🤨 wtf does telnet do? telnet came

Reflections on TIL posts

TL;DR Here are things I found helpful the past few days: * Set goals, set time limits, enforce with timers * Outline, outline, outline * Be genuine The Experiment Last Wednesday, I decided [https://pcarleton.com/2018/05/30/til/] to try out a new blog format with shorter posts covering topics

linux networking Featured

Why does TCP even need a 3-way handshake?

The 3-way handshake. It's inevitable in any TCP discussion that you mention the TCP connection establishment three-way handshake. After writing about QUIC and how it aims to have 0-RTT connection establishment cost, I started wondering why TCP needed that 1-RTT 3-way handshake in the first place.

linux networking Featured

TIL: QUIC is like TLS over UDP

QUIC (Quick UDP Internet Connections) is a new(ish) protocol for developing applications on the internet. It aims to provide TLS-like encryption without the overhead of TCP.

linux networking

TIL: The difference between netstat and ss

Motivation In this post, I'm going to go over two tools for inspecting the socket states ( netstat and ss), and why to choose one over the other (spoiler: you can really choose either). This is not going to be a 12 ways to inspect socket states article, there are lots

linux networking

TIL: There are 16 T1 Internet Service Providers

I've been collecting information for a "Practical Guide to Linux Networking" by reading material I can find. Two things I've been reading recently are: * A Practical Guide to (Correctly) Troubleshooting with Traceroute [https://www.nanog.org/meetings/nanog47/presentations/Sunday/RAS_Traceroute_N47_Sun.pdf] * a presentation by Richard A

TIL

New Format: Today I Learned

I am going to try a new format where I write about something I learned. My goals with this format are: * Increase the amount of writing I do * Increase the frequency of writing * Lower the barrier for making a new post * Document things I've learned My rough goal is to

rust

Dumb dig clone in Rust

Why write a DNS client When I started digging in to DNS, I thought it would be interesting to try implementing a very simple DNS client similar to dig, but using Rust. My goal was to better understand DNS at the protocol level. I wanted to know what bytes were

linux networking

Starting to figure out SSL

Introduction I've been slowly working towards a personal finance app, but before I can actually put it on the open web, I want to be reasonably confident that I am not opening myself up to being hacked. One of the pieces to that puzzle is having secure connections in the

linux networking

Meandering History of DNS Authority

As a follow up to my DNS post, I started trying to answer "Who's in charge of all this?". Basically, I wanted to know what keeps me from claiming a different domain name or for that matter for claiming a different IP address. I went down a rabbit hole of

Wifi

Wifi Woes resolved with Ubiquiti

Fast Wifi is possible! I have declared my Ubiquiti experiment a success! I am consistently measuring internet speeds over 100 MB/s with the lowest I've seen around 40 MB/s. This is a huge upgrade from seeing 5-8 MB/s regularly with the highest being around 15 MB/s

Wifi

Debugging Slow Wifi

Introduction I ran into the ever common problem of slow WiFi recently. In this post I want to detail the experiments I ran and what I gleaned from the results. Setting the Stage First I'll describe the setup I have for my home wifi network and the problems I was

linux networking

DNS End to End

Domain Name System: End to End We all interact with the Domain Name System (DNS) every day. Every time we load a web page, or click a link, our software relies on DNS to figure out what address to send requests to. In this post, I will dig into how

Linux

What does mount do?

Background As I mentioned in my [post about containers][container-post], I want to write a container tool in rust to learn more about rust and containers. I started doing that with my friend Kevin, and our (humble) progress so far is on Github in a project we called bucket [https: