53 pages

Go

The config key that quietly did nothing

I once spent the better part of an hour convinced a timeout setting was broken. I’d set it in the config file, the tool ignored it, and the code that read it looked perfectly correct. The setting was tiemout. I’d typed …

One variadic, and I'd already spent it

I had a constructor I was rather pleased with. Hand go-tool-base’s root command its props and as many sub-commands as you like, and off it goes. Then I needed to thread some config file paths through it, reached for the …

Half your users don't have eyes

Run a command in your favourite CLI tool and look at what comes back. Colour. Neatly aligned columns. A friendly little summary sentence. Lovely… if you happen to be a human with eyes. But a good half of any tool’s users …

Lifecycle management for when your CLI grows up into a service

There’s a moment in the life of a lot of CLI tools where they stop being a CLI tool. Nobody quite decides it. It just happens. Someone needs the thing to also expose a little HTTP endpoint, or poll a queue, or run a …

Middleware for CLI commands, not just web servers

Every CLI tool past a certain size grows a category of logic that doesn’t really belong to any one command, and yet has to happen for loads of them. Timing. An auth check. Panic recovery, so a crash becomes a clean error …

A logging interface that doesn't leak its backend

The same tool, in two different lives, wants two completely different kinds of log. On my laptop I want logs I can actually read: colour, alignment, friendly timestamps. The very same tool running as a daemon in a …

Errors that tell the user what to do next

Here’s an error message I’ve been on the receiving end of more times than I’d care to count: error: failed to read config file True. Also completely useless! I now know something is broken and I haven’t the faintest idea …

Many embedded filesystems, one merged view

Go’s embed package is one of those features that makes you slightly giddy the first time you use it. One //go:embed directive and your default config, your templates, your docs are all baked into the binary. The tool …

Props: the container that does the heavy lifting

I name-dropped Props back in the introduction and then rather glossed over it, which was a bit unfair of me, because it’s the single most important design decision in the whole framework. So let’s give it the attention …

Design your whole CLI in one file

Here’s a question that sounds trivial and really isn’t: where, exactly, does a CLI tool’s structure live? Not the logic of each command… the structure. Which commands exist, what they’re called, which flags they take, …