golang-viper

What problem does it solve?

Go applications often need flexible configuration sources. Viper unifies reading from config files, environment variables, defaults, and remote stores, simplifying maintainable configuration management.

Core Features & Use Cases

• Unified config sources: read YAML/JSON/TOML files, bind environment variables, apply defaults, and support remote key/value stores.
• Environment prioritization and nested keys: overrides from env vars withPrefix and key replacers, mapping to nested Go structs.
• Easy integration: unmarshall into Go structs, watch for changes, and compose multiple config files for secrets or overrides.

Quick Start

• Create a config file (for example config.yaml) and place keys under server.host and server.port.
• In your Go code, initialize Viper with a config name and paths, set a config type if needed, load the config, and access values using viper.GetString("server.host") or viper.GetInt("server.port").
• Optional: enable environment variable overrides by setting a prefix and enabling AutomaticEnv, plus set defaults before reading in config.