The config key that quietly did nothing
Config loaders ignore keys they do not recognise, so a typo runs on the old value. Deriving a validation schema from struct tags to catch it.
Tags
73 pages
Go
One variadic, and I'd already spent it
Go allows only one trailing variadic parameter, so adding another argument to a function that already has one is impossible. What to do instead.
Half your users don't have eyes
The other audience for a CLI is the script that greps its output and breaks. Giving every command a JSON output mode with one response envelope.
Lifecycle management for when your CLI grows up into a service
When a Go CLI grows into a service: ordered graceful shutdown on SIGTERM, separate liveness and readiness probes, and an opt-in restart supervisor.
Middleware for CLI commands, not just web servers
Timing, auth, recovery and logging are cross-cutting in a CLI too. Wrapping Cobra commands in web-style middleware rather than PreRun hooks.
A logging interface that doesn't leak its backend
One tool, three logging backends: colour for a terminal, JSON for a container, silence for tests. Depend on the interface, choose the backend once.
Errors that tell the user what to do next
Recovery advice belongs in a structured error hint, not buried in the message string. One error handler then decides how to show it.
Many embedded filesystems, one merged view
Go embed.FS is per-package, so a modular CLI ends up with islands. Merging them into one filesystem, and deep-merging YAML and JSON across them.
Props: the container that does the heavy lifting
Passing dependencies to Go commands in a typed struct rather than stuffing them in context.Context, so the compiler checks them and tests stay simple.
Design your whole CLI in one file
go-tool-base keeps an entire CLI command tree in one manifest file and generates the wiring from it, without locking you out of hand-written Go.
