The Cobra CLI

Using cobra in your project is as simple as importing github.com/spf13/cobra where you need it, and then building out your command structure. If you're just getting started using cobra, however, it may be beneficial to instead use cobra-cli, which is a scaffolding tool for cobra applications.

We'll use that here, but just know that it's not a requirement. You can just as easily start your CLI project by importing cobra and laying out your project as you want.

Follow the instructions here for installing the Cobra command line tool. The instructions indicate that you'll install the "latest" version of cobra-cli, which at the time of this writing appears to be v1.3.0. The commands you see here may differ slightly if you have a different version, but that's okay.

Once you've installed cobra-cli, make sure it's in your $PATH by calling

cobra-cli --help

If the you get a command not found error (or similar, then that implies that your $GOBIN is not in your $PATH). Resolve that first before moving on.

This book will build out a math binary that has several mathematical operations encompassed as subcommands. Like I mentioned, it's a bit silly and contrived, but we don't really want to implement a ton of logic here - we just want to see what we can do with cobra.

The completed source code for the command built here will be available at https://github.com/opdev/cobra-primer/math.