golang-viper

You can manage Go application configuration by using Viper to unify reading from YAML, JSON, and TOML config files alongside environment variables and defaults. This centralizes configuration management into a single source of truth.

To map nested environment variables to Go structs in Viper, you set an environment prefix and enable AutomaticEnv with key replacers. You then use unmarshalling to map these overridden nested keys directly into your Go structs.

Yes, you can override YAML config values with environment variables in a Go app by enabling Viper's environment prioritization. Setting a prefix and enabling AutomaticEnv ensures environment variables take precedence over file values.

The best way to read multiple config files for secrets and overrides in Go is composing multiple config files with Viper. This approach allows you to merge base configurations with separate files containing secrets or environment overrides.

Yes, Viper supports hot reloading configuration changes at runtime in Go applications. You can watch for changes in your config files, allowing your Go application to dynamically update settings without requiring a restart.

Before reading config values with Viper in Go, you need the Viper library, a config file in YAML, JSON, or TOML format, an optional environment prefix, and basic Go tooling to initialize config paths and read values.