Where is this IP coming from?

Sometimes you really want to know where an IP is coming from. Whether you are doing abuse or threat hunts, or just want to know who owns that IP blocked by fail2ban for spamming your SSH server. Each IP belongs to a specifc Autonomous System. An autonomous system (AS) is a very large network or group of networks with a single routing policy. Each AS is assigned a unique ASN, which is a number that identifies the AS....

Another password manager

I’ve been playing with password managers on and off for a long time. The first personal desktop app that I wrote was called JPasskeep and was written in Java Swing to explore Java’s cryptography and UI design and interaction patterns. It was a good experience and helped me get a gig as the UI engineer on a nifty Android project many years later. I’ve used JPasskeep on and off over the years, mostly on consulting gigs when I needed to store passwords on various development machines, and storing them as ....

I'm being stubborn

I’ve been writing a lot of Go code for the past few years and I have really come to appreciate the code generation patterns that Go developers use. In this case, the excellent Moq library to generate test doubles for unit tests. No third-party code is necessary to use these test doubles, which is an unusual joy nowadays with masses of transitive dependencies frequently required for anything interesting. One thing that has been bugging me for a while with moq is that in its documentation and generated code it calls these test doubles mocks when they are clearly stubs....

Gotchas with static sites on S3 via CloudFront

There’s a ton of posts already on how to set up static sites hosted on S3 via CloudFront. This isn’t going to be one of them. What I want to discuss is some weirdness that I encountered with setting up this blog. For the purpose of this post we’re going to assume that you are going to create a hypothetical static site: https://example.com If you host a static site on hardware, or a VPS (be it an EC2 instance or a DigitalOcean Droplet) you’ll most likely do this with one of the various available web servers, like nginx or apache, and use a service like Let’s Encrypt to create the TLS certificate....

Diceware passphrase generator

There are many ways to generate passwords, and to avoid passwords in the first place (which you really should do), but I wanted a little practice in writing interactive bash scripts. So I chose to create a password generator based on the Diceware algorithm, even though I don’t carry any dice with me. Find of the day is the excellent gum tool that makes it easy to create pretty user interaction....

Good-enough leader election with MySQL

Leader election, in distributed computing, is the process of designating a single process as the organizer of some task distributed among several computers (nodes). Before the task has began, all network nodes are either unaware which node will serve as the “leader” (or coordinator) of the task, or unable to communicate with the current coordinator. After a leader election algorithm has been run, however, each node throughout the network recognizes a particular, unique node as the task leader....

GitHub Actions for Build & Release

I like to write code, build, and release tooling, for my brain at 3 AM. No surprises, no clever bits to trip me up. Lately I’ve been playing with GitHub Actions to build and deploy some of my public projects. It took a little while to figure out something that I could copy and paste between them, and I’d like to share what I’ve managed to come up with. Build Actions Committed to your project as ....

Standalone mode for Redis clients

I’ve been playing around with using an in-process redis using miniredis as the backing store for a service that relies on go-workers2 for background processing. You can find the code in my example-miniredis project on GitHub. While miniredis was created as something to be only used in unit tests, this may be useful in running a service that normally requires a redis in a totally standalone mode. I view such a standalone mode as critical for a good development experience in creating integrations against a service, since you can run the service locally without any of its downstream dependencies and still expect to have it respond sensibly....

gRPC server & grpc-gateway authentication

It has taken me far too long to figure out all the minute details of how to apply authentication to gRPC-based services, how to do that using the HTTP/JSON grpc-gateway, and then how to run a gRPC server and a grpc-gateway side-by-side using the same service instance in a way that makes sense to me. There’s a surprising amount of detail that is not documented and there are a few gotchas for the unwary traveller....

Golang SQL Boilerplate

My day job currently includes writing and maintaining golang services. It’s not a bad language, and it certainly forces you to understand that everything will fail, far more obviously than Java’s checked exceptions. I’m not going to argue about the utility of checking/returning error instances, but I do find myself writing the same code over and over again, especially when I’m handling any SQL operations. So I’ve come up with a couple of templates to remove a bunch of the boilerplate code for transactions and for looping over SQL query result rows....