README
¶
viper
Go configuration with fangs
What is Viper?
Viper is a complete configuration solution. Designed to work within an application to handle file based configuration and seamlessly marry that with command line flags which can also be used to control application behavior.
Why Viper?
When building a modern application you don’t want to have to worry about configuration file formats, you want to focus on building awesome software. Viper is here to help with that.
Viper does the following for you:
- Find, load and marshall a configuration file in YAML, TOML or JSON.
- Provide a mechanism to setDefault values for your different configuration options
- Provide a mechanism to setOverride values for options specified through command line flags.
- Provide an alias system to easily rename parameters without breaking existing code.
- Make it easy to tell the difference between when a user has provided a command line or config file which is the same as the default.
Viper believes that:
- command line flags take precedence over options set in config files
- config files take precedence over defaults
Config files often can be found in multiple locations. Viper allows you to set multiple paths to search for the config file in.
Viper configuration keys are case insensitive.
Usage
Initialization
viper.SetConfigName("config") // name of config file (without extension)
viper.AddConfigPath("/etc/appname/") // path to look for the config file in
viper.AddConfigPath("$HOME/.appname") // call multiple times to add many search paths
viper.ReadInConfig() // Find and read the config file
Setting Defaults
viper.SetDefault("ContentDir", "content")
viper.SetDefault("LayoutDir", "layouts")
viper.SetDefault("Indexes", map[string]string{"tag": "tags", "category": "categories"})
Setting Overrides
viper.Set("Verbose", true)
viper.Set("LogFile", LogFile)
Registering and Using Aliases
viper.RegisterAlias("loud", "Verbose")
viper.Set("verbose", true) // same result as next line
viper.Set("loud", true) // same result as prior line
viper.GetBool("loud") // true
viper.GetBool("verbose") // true
Getting Values
viper.GetString("logfile") // case insensitive Setting & Getting
if viper.GetBool("verbose") {
fmt.Println("verbose enabled")
}
Q & A
Q: Why not INI files?
A: Ini files are pretty awful. There’s no standard format and they are hard to validate. Viper is designed to work with YAML, TOML or JSON files. If someone really wants to add this feature, I’d be happy to merge it. It’s easy to specify which formats your application will permit.
Q: Why is it called "viper"?
A: Viper is designed to be a companion to Cobra. While both can operate completely independently, together they make a powerful pair to handle much of your application foundation needs.
Q: Why is it called "Cobra"?
A: Is there a better name for a commander?
Documentation
¶
Index ¶
- Variables
- func AddConfigPath(in string)
- func AllKeys() []string
- func AllSettings() map[string]interface{}
- func AutomaticEnv()
- func BindEnv(input ...string) (err error)
- func BindPFlag(key string, flag *pflag.Flag) (err error)
- func ConfigFileUsed() string
- func Debug()
- func Get(key string) interface{}
- func GetBool(key string) bool
- func GetFloat64(key string) float64
- func GetInt(key string) int
- func GetString(key string) string
- func GetStringMap(key string) map[string]interface{}
- func GetStringMapString(key string) map[string]string
- func GetStringSlice(key string) []string
- func GetTime(key string) time.Time
- func InConfig(key string) bool
- func IsSet(key string) bool
- func Marshal(rawVal interface{}) error
- func MarshalKey(key string, rawVal interface{}) error
- func MarshallReader(in io.Reader)
- func ReadInConfig() error
- func RegisterAlias(alias string, key string)
- func Reset()
- func Set(key string, value interface{})
- func SetConfigFile(in string)
- func SetConfigName(in string)
- func SetConfigType(in string)
- func SetDefault(key string, value interface{})
- type UnsupportedConfigError
Constants ¶
This section is empty.
Variables ¶
var SupportedExts []string = []string{"json", "toml", "yaml", "yml"}
extensions Supported
Functions ¶
func AddConfigPath ¶
func AddConfigPath(in string)
func AllSettings ¶
func AllSettings() map[string]interface{}
func AutomaticEnv ¶
func AutomaticEnv()
Have viper check ENV variables for all keys set in config, default & flags
func BindEnv ¶
Binds a viper key to a ENV variable ENV variables are case sensitive If only a key is provided, it will use the env key matching the key, uppercased.
func BindPFlag ¶
Bind a specific key to a flag (as used by cobra)
serverCmd.Flags().Int("port", 1138, "Port to run Application server on")
viper.BindPFlag("port", serverCmd.Flags().Lookup("port"))
func ConfigFileUsed ¶
func ConfigFileUsed() string
func Get ¶
func Get(key string) interface{}
Get returns an interface.. Must be typecast or used by something that will typecast
func GetFloat64 ¶
func GetStringMap ¶
func GetStringMapString ¶
func GetStringSlice ¶
func MarshalKey ¶
Takes a single key and marshals it into a Struct
func MarshallReader ¶
func ReadInConfig ¶
func ReadInConfig() error
Viper will discover and load the configuration file from disk searching in one of the defined paths.
func RegisterAlias ¶
Aliases provide another accessor for the same key. This enables one to change a name without breaking the application
func Set ¶
func Set(key string, value interface{})
The user provided value (via flag) Will be used instead of values obtained via config file, ENV or default
func SetConfigFile ¶
func SetConfigFile(in string)
Explicitly define the path, name and extension of the config file Viper will use this and not check any of the config paths
func SetConfigName ¶
func SetConfigName(in string)
Name for the config file. Does not include extension.
func SetConfigType ¶
func SetConfigType(in string)
func SetDefault ¶
func SetDefault(key string, value interface{})
Set the default value for this key. Default only used when no value is provided by the user via flag, config or ENV.
Types ¶
type UnsupportedConfigError ¶
type UnsupportedConfigError string
func (UnsupportedConfigError) Error ¶
func (str UnsupportedConfigError) Error() string
Source Files