Golang Viper Configuration

Viper is Go's most popular configuration library. It handles config files, environment variables, defaults, and remote config stores with a unified API.

Config Precedence (highest to lowest)

1. viper.Set() - explicit runtime overrides
2. Command-line flags (via pflag)
3. Environment variables
4. Config files
5. Remote key/value stores (etcd, Consul)
6. viper.SetDefault() - defaults

Quick Reference