What is viper?

Viper is a popular configuration management solution for Go applications. It prioritizes flexibility and ease of use, allowing developers to configure applications from various sources without tightly coupling them to specific configuration formats.

Here's a breakdown of key aspects:

• Configuration Sources: Viper supports a wide array of configuration sources including:

  • JSON files
  • YAML files
  • TOML files
  • INI files
  • Environment variables
  • Command-line flags
  • Remote key/value stores (etcd, Consul, etc.)

• Configuration Merging: Viper intelligently merges configuration data from multiple sources, establishing a precedence order. This allows you to override default settings with environment variables or command-line flags.

• Configuration Watching: Viper can watch configuration files and automatically reload them when changes occur. This is particularly useful for applications that need to adapt to configuration updates without requiring a restart.

• Key Features:

  • Support for default values
  • Automatic environment variable binding (e.g., DATABASE_URL maps to a database_url configuration key)
  • Aliases for configuration keys
  • Easy access to configuration values using methods like GetString, GetInt, GetBool, etc.
  • Integration with flag package