cli_skill

This skill helps you build production-grade Go CLIs with Cobra and Viper, coordinating commands and flexible configuration across environments.

Python

13

GitHub Stars

2

Bundled Files

2 months ago

Catalog Refreshed

4 months ago

First Indexed

Readme & install

Copy the install command, review bundled files from the catalogue, and read any extended description pulled from the listing source.

Installation

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npx veilstrat add skill bobmatnyc/claude-mpm-skills --skill cli

metadata.json407 B
SKILL.md27.2 KB

Overview

This skill shows how to build production-quality Go CLI tools using the Cobra command framework together with Viper for configuration management. It focuses on common patterns: command/subcommand structure, flag and config binding, environment mapping, and shell completion. The content emphasizes proven patterns used by major projects and practical integration details for reliable, maintainable CLIs.

How this skill works

It inspects the recommended Cobra command patterns (root commands, subcommands, PreRun/Run/PostRun hooks) and demonstrates binding flags to Viper keys so configuration flows predictably. It explains Viper priority rules (flags > env vars > config files > defaults), config file locations and formats, and techniques to load and validate configuration before command execution. It also covers generating shell completion scripts for bash, zsh, fish, and PowerShell.

When to use it

Building multi-command CLIs with subcommands and complex args
Creating developer tools, scaffolding, or admin utilities that need robust config
When you need flexible configuration sources: flags, env vars, config files, defaults
Adding shell completion for frequent CLI users
Implementing DevOps automation, deployment, or service admin commands

Best practices

Use cobra.OnInitialize or PersistentPreRunE to load and validate configuration before running commands
Bind persistent flags globally and bind local flags inside each command init() to keep scope clear
Prefer RunE/PreRunE/PostRunE (error-returning hooks) to allow proper error handling
Set sensible defaults via viper.SetDefault and document environment variable mappings with viper.SetEnvPrefix and AutomaticEnv
Use viper.Unmarshal into typed structs for type-safe access and validation

Example use cases

A deployment CLI with a deploy subcommand that validates production deploys require --force
An ops tool that reads credentials from env vars or a config file and initializes clients in PersistentPreRunE
A developer scaffolding tool with subcommands for generate, test, and publish and per-command flags bound to Viper
A service CLI that supports user config files, environment overrides, and auto-generated shell completions for improved UX

FAQ

Bind flags to Viper with viper.BindPFlag after defining the flag; Viper treats bound flags as higher precedence than config files.

Where should I load and validate configuration?

Load defaults and config files in the initConfig called by cobra.OnInitialize or use PersistentPreRunE on the root command to validate required values and initialize clients.