diff --git a/viper.go b/viper.go index be41206..1f25785 100644 --- a/viper.go +++ b/viper.go @@ -10,6 +10,7 @@ // Each item takes precedence over the item below it: +// overrides // flag // env // config @@ -43,26 +44,68 @@ func init() { v = New() } +// Denotes encountering an unsupported +// configuration filetype. type UnsupportedConfigError string +// Returns the formatted configuration error. func (str UnsupportedConfigError) Error() string { return fmt.Sprintf("Unsupported Config Type %q", string(str)) } +// Denotes encountering an unsupported remote +// provider. Currently only Etcd and Consul are +// supported. type UnsupportedRemoteProviderError string +// Returns the formatted remote provider error. func (str UnsupportedRemoteProviderError) Error() string { return fmt.Sprintf("Unsupported Remote Provider Type %q", string(str)) } +// Denotes encountering an error while trying to +// pull the configuration from the remote provider. type RemoteConfigError string +// Returns the formatted remote provider error func (rce RemoteConfigError) Error() string { return fmt.Sprintf("Remote Configurations Error: %s", string(rce)) } -// A Viper is a unexported struct. Use New() to create a new instance of viper -// or use the functions for a "global instance" +// Viper is a prioritized configuration registry. It +// maintains a set of configuration sources, fetches +// values to populate those, and provides them according +// to the source's priority. +// The priority of the sources is the following: +// 1. overrides +// 2. flags +// 3. env. variables +// 4. config file +// 5. key/value store +// 6. defaults +// +// For example, if values from the following sources were loaded: +// +// Defaults : { +// "secret": "", +// "user": "default", +// "endpoint": "https://localhost" +// } +// Config : { +// "user": "root" +// "secret": "defaultsecret" +// } +// Env : { +// "secret": "somesecretkey" +// } +// +// The resulting config will have the following values: +// +// { +// "secret": "somesecretkey", +// "user": "root", +// "endpoint": "https://localhost" +// } type Viper struct { // A set of paths to look for the config file in configPaths []string @@ -88,7 +131,7 @@ type Viper struct { aliases map[string]string } -// The prescribed way to create a new Viper +// Returns an initialized Viper instance. func New() *Viper { v := new(Viper) v.configName = "config" @@ -123,10 +166,10 @@ type remoteProvider struct { secretKeyring string } -// universally supported extensions +// Universally supported extensions. var SupportedExts []string = []string{"json", "toml", "yaml", "yml"} -// universally supported remote providers +// Universally supported remote providers. var SupportedRemoteProviders []string = []string{"etcd", "consul"} // Explicitly define the path, name and extension of the config file @@ -139,6 +182,8 @@ func (v *Viper) SetConfigFile(in string) { } // Define a prefix that ENVIRONMENT variables will use. +// E.g. if your prefix is "spf", the env registry +// will look for env. variables that start with "SPF_" func SetEnvPrefix(in string) { v.SetEnvPrefix(in) } func (v *Viper) SetEnvPrefix(in string) { if in != "" { @@ -168,7 +213,7 @@ func (v *Viper) getEnv(key string) string { return os.Getenv(key) } -// Return the config file used +// Return the file used to populate the config registry func ConfigFileUsed() string { return v.ConfigFileUsed() } func (v *Viper) ConfigFileUsed() string { return v.configFile } @@ -259,7 +304,7 @@ func (v *Viper) providerPathExists(p *remoteProvider) bool { // Get can retrieve any value given the key to use // Get has the behavior of returning the value associated with the first // place from where it is set. Viper will check in the following order: -// flag, env, config file, key/value store, default +// override, flag, env, config file, key/value store, default // // Get returns an interface. For a specific value use one of the Get____ methods. func Get(key string) interface{} { return v.Get(key) } @@ -290,51 +335,62 @@ func (v *Viper) Get(key string) interface{} { return val } +// Returns the value associated with the key as a string func GetString(key string) string { return v.GetString(key) } func (v *Viper) GetString(key string) string { return cast.ToString(v.Get(key)) } +// Returns the value associated with the key asa boolean func GetBool(key string) bool { return v.GetBool(key) } func (v *Viper) GetBool(key string) bool { return cast.ToBool(v.Get(key)) } +// Returns the value associated with the key as an integer func GetInt(key string) int { return v.GetInt(key) } func (v *Viper) GetInt(key string) int { return cast.ToInt(v.Get(key)) } +// Returns the value associated with the key as a float64 func GetFloat64(key string) float64 { return v.GetFloat64(key) } func (v *Viper) GetFloat64(key string) float64 { return cast.ToFloat64(v.Get(key)) } +// Returns the value associated with the key as time func GetTime(key string) time.Time { return v.GetTime(key) } func (v *Viper) GetTime(key string) time.Time { return cast.ToTime(v.Get(key)) } +// Returns the value associated with the key as a duration func GetDuration(key string) time.Duration { return v.GetDuration(key) } func (v *Viper) GetDuration(key string) time.Duration { return cast.ToDuration(v.Get(key)) } +// Returns the value associated with the key as a slice of strings func GetStringSlice(key string) []string { return v.GetStringSlice(key) } func (v *Viper) GetStringSlice(key string) []string { return cast.ToStringSlice(v.Get(key)) } +// Returns the value associated with the key as a map of interfaces func GetStringMap(key string) map[string]interface{} { return v.GetStringMap(key) } func (v *Viper) GetStringMap(key string) map[string]interface{} { return cast.ToStringMap(v.Get(key)) } +// Returns the value associated with the key as a map of strings func GetStringMapString(key string) map[string]string { return v.GetStringMapString(key) } func (v *Viper) GetStringMapString(key string) map[string]string { return cast.ToStringMapString(v.Get(key)) } +// Returns the size of the value associated with the given key +// in bytes. func GetSizeInBytes(key string) uint { return v.GetSizeInBytes(key) } func (v *Viper) GetSizeInBytes(key string) uint { sizeStr := cast.ToString(v.Get(key)) @@ -347,7 +403,8 @@ func (v *Viper) MarshalKey(key string, rawVal interface{}) error { return mapstructure.Decode(v.Get(key), rawVal) } -// Marshals the config into a Struct +// Marshals the config into a Struct. Make sure that the tags +// on the fields of the structure are properly set. func Marshal(rawVal interface{}) error { return v.Marshal(rawVal) } func (v *Viper) Marshal(rawVal interface{}) error { err := mapstructure.WeakDecode(v.AllSettings(), rawVal) @@ -362,6 +419,7 @@ func (v *Viper) Marshal(rawVal interface{}) error { } // Bind a specific key to a flag (as used by cobra) +// Example(where serverCmd is a Cobra instance): // // serverCmd.Flags().Int("port", 1138, "Port to run Application server on") // Viper.BindPFlag("port", serverCmd.Flags().Lookup("port")) @@ -490,6 +548,8 @@ func (v *Viper) AutomaticEnv() { } // SetEnvKeyReplacer sets the strings.Replacer on the viper object +// Useful for mapping an environmental variable to a key that does +// not match it. func SetEnvKeyReplacer(r *strings.Replacer) { v.SetEnvKeyReplacer(r) } func (v *Viper) SetEnvKeyReplacer(r *strings.Replacer) { v.envKeyReplacer = r @@ -563,9 +623,9 @@ func (v *Viper) SetDefault(key string, value interface{}) { v.defaults[key] = value } -// The user provided value (via flag) +// Sets the value for the key in the override regiser. // Will be used instead of values obtained via -// config file, ENV, default, or key/value store +// flags, config file, ENV, default, or key/value store func Set(key string, value interface{}) { v.Set(key, value) } func (v *Viper) Set(key string, value interface{}) { // If alias passed in, then set the proper override @@ -591,6 +651,8 @@ func (v *Viper) ReadInConfig() error { return nil } +// Attempts to get configuration from a remote source +// and read it in the remote configuration registry. func ReadRemoteConfig() error { return v.ReadRemoteConfig() } func (v *Viper) ReadRemoteConfig() error { err := v.getKeyValueConfig() @@ -710,6 +772,8 @@ func (v *Viper) SetConfigName(in string) { } } +// Sets the type of the configuration returned by the +// remote source, e.g. "json". func SetConfigType(in string) { v.SetConfigType(in) } func (v *Viper) SetConfigType(in string) { if in != "" { @@ -781,6 +845,8 @@ func (v *Viper) findConfigFile() (string, error) { return "", fmt.Errorf("config file not found in: %s", v.configPaths) } +// Prints all configuration registries for debugging +// purposes. func Debug() { v.Debug() } func (v *Viper) Debug() { fmt.Println("Config:")