spf13--viper/viper.go
2015-02-06 14:35:00 -06:00

849 lines
22 KiB
Go

// Copyright © 2014 Steve Francia <spf@spf13.com>.
//
// Use of this source code is governed by an MIT-style
// license that can be found in the LICENSE file.
// Viper is a application configuration system.
// It believes that applications can be configured a variety of ways
// via flags, ENVIRONMENT variables, configuration files retrieved
// from the file system, or a remote key/value store.
// Each item takes precedence over the item below it:
// flag
// env
// config
// key/value store
// default
package viper
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"reflect"
"strings"
"time"
"github.com/kr/pretty"
"github.com/mitchellh/mapstructure"
"github.com/spf13/cast"
jww "github.com/spf13/jwalterweatherman"
"github.com/spf13/pflag"
crypt "github.com/xordataexchange/crypt/config"
)
var v *viper
func init() {
v = New()
}
type UnsupportedConfigError string
func (str UnsupportedConfigError) Error() string {
return fmt.Sprintf("Unsupported Config Type %q", string(str))
}
type UnsupportedRemoteProviderError string
func (str UnsupportedRemoteProviderError) Error() string {
return fmt.Sprintf("Unsupported Remote Provider Type %q", string(str))
}
type RemoteConfigError string
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"
type viper struct {
// A set of paths to look for the config file in
configPaths []string
// A set of remote providers to search for the configuration
remoteProviders []*remoteProvider
// Name of file to look for inside the path
configName string
configFile string
configType string
envPrefix string
automaticEnvApplied bool
cascadeConfigurations bool
config map[string]interface{}
override map[string]interface{}
defaults map[string]interface{}
kvstore map[string]interface{}
cascadingConfigs map[string]map[string]interface{}
pflags map[string]*pflag.Flag
env map[string]string
aliases map[string]string
}
// The prescribed way to create a new Viper
func New() *viper {
v := new(viper)
v.configName = "config"
v.config = make(map[string]interface{})
v.override = make(map[string]interface{})
v.defaults = make(map[string]interface{})
v.kvstore = make(map[string]interface{})
v.pflags = make(map[string]*pflag.Flag)
v.env = make(map[string]string)
v.aliases = make(map[string]string)
v.cascadeConfigurations = false
return v
}
// remoteProvider stores the configuration necessary
// to connect to a remote key/value store.
// Optional secretKeyring to unencrypt encrypted values
// can be provided.
type remoteProvider struct {
provider string
endpoint string
path string
secretKeyring string
}
// universally supported extensions
var SupportedExts []string = []string{"json", "toml", "yaml", "yml"}
// universally supported remote providers
var SupportedRemoteProviders []string = []string{"etcd", "consul"}
// Explicitly define the path, name and extension of the config file
// Viper will use this and not check any of the config paths
func SetConfigFile(in string) { v.SetConfigFile(in) }
func (v *viper) SetConfigFile(in string) {
if in != "" {
v.configFile = in
}
}
// Define a prefix that ENVIRONMENT variables will use.
func SetEnvPrefix(in string) { v.SetEnvPrefix(in) }
func (v *viper) SetEnvPrefix(in string) {
if in != "" {
v.envPrefix = in
}
}
// Enable cascading configuration values for files. Will traverse down
// ConfigPaths in an attempt to find keys
func (v *viper) EnableCascading(enable bool){
v.cascadeConfigurations = enable;
}
func (v *viper) mergeWithEnvPrefix(in string) string {
if v.envPrefix != "" {
return strings.ToUpper(v.envPrefix + "_" + in)
}
return strings.ToUpper(in)
}
// Return the config file used
func ConfigFileUsed() string { return v.ConfigFileUsed() }
func (v *viper) ConfigFileUsed() string { return v.configFile }
// Add a path for viper to search for the config file in.
// Can be called multiple times to define multiple search paths.
func AddConfigPath(in string) { v.AddConfigPath(in) }
func (v *viper) AddConfigPath(in string) {
if in != "" {
absin := absPathify(in)
jww.INFO.Println("adding", absin, "to paths to search")
if !stringInSlice(absin, v.configPaths) {
v.configPaths = append(v.configPaths, absin)
}
}
}
// AddRemoteProvider adds a remote configuration source.
// Remote Providers are searched in the order they are added.
// provider is a string value, "etcd" or "consul" are currently supported.
// endpoint is the url. etcd requires http://ip:port consul requires ip:port
// path is the path in the k/v store to retrieve configuration
// To retrieve a config file called myapp.json from /configs/myapp.json
// you should set path to /configs and set config name (SetConfigName()) to
// "myapp"
func AddRemoteProvider(provider, endpoint, path string) error {
return v.AddRemoteProvider(provider, endpoint, path)
}
func (v *viper) AddRemoteProvider(provider, endpoint, path string) error {
if !stringInSlice(provider, SupportedRemoteProviders) {
return UnsupportedRemoteProviderError(provider)
}
if provider != "" && endpoint != "" {
jww.INFO.Printf("adding %s:%s to remote provider list", provider, endpoint)
rp := &remoteProvider{
endpoint: endpoint,
provider: provider,
path: path,
}
if !v.providerPathExists(rp) {
v.remoteProviders = append(v.remoteProviders, rp)
}
}
return nil
}
// AddSecureRemoteProvider adds a remote configuration source.
// Secure Remote Providers are searched in the order they are added.
// provider is a string value, "etcd" or "consul" are currently supported.
// endpoint is the url. etcd requires http://ip:port consul requires ip:port
// secretkeyring is the filepath to your openpgp secret keyring. e.g. /etc/secrets/myring.gpg
// path is the path in the k/v store to retrieve configuration
// To retrieve a config file called myapp.json from /configs/myapp.json
// you should set path to /configs and set config name (SetConfigName()) to
// "myapp"
// Secure Remote Providers are implemented with github.com/xordataexchange/crypt
func AddSecureRemoteProvider(provider, endpoint, path, secretkeyring string) error {
return v.AddSecureRemoteProvider(provider, endpoint, path, secretkeyring)
}
func (v *viper) AddSecureRemoteProvider(provider, endpoint, path, secretkeyring string) error {
if !stringInSlice(provider, SupportedRemoteProviders) {
return UnsupportedRemoteProviderError(provider)
}
if provider != "" && endpoint != "" {
jww.INFO.Printf("adding %s:%s to remote provider list", provider, endpoint)
rp := &remoteProvider{
endpoint: endpoint,
provider: provider,
path: path,
}
if !v.providerPathExists(rp) {
v.remoteProviders = append(v.remoteProviders, rp)
}
}
return nil
}
func (v *viper) providerPathExists(p *remoteProvider) bool {
for _, y := range v.remoteProviders {
if reflect.DeepEqual(y, p) {
return true
}
}
return false
}
// Viper is essentially repository for configurations
// 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
//
// Get returns an interface. For a specific value use one of the Get____ methods.
func Get(key string) interface{} { return v.Get(key) }
func (v *viper) Get(key string) interface{} {
key = strings.ToLower(key)
val := v.find(key)
if val == nil {
return nil
}
switch val.(type) {
case bool:
return cast.ToBool(val)
case string:
return cast.ToString(val)
case int64, int32, int16, int8, int:
return cast.ToInt(val)
case float64, float32:
return cast.ToFloat64(val)
case time.Time:
return cast.ToTime(val)
case []string:
return val
}
return val
}
func GetString(key string) string { return v.GetString(key) }
func (v *viper) GetString(key string) string {
return cast.ToString(v.Get(key))
}
func GetBool(key string) bool { return v.GetBool(key) }
func (v *viper) GetBool(key string) bool {
return cast.ToBool(v.Get(key))
}
func GetInt(key string) int { return v.GetInt(key) }
func (v *viper) GetInt(key string) int {
return cast.ToInt(v.Get(key))
}
func GetFloat64(key string) float64 { return v.GetFloat64(key) }
func (v *viper) GetFloat64(key string) float64 {
return cast.ToFloat64(v.Get(key))
}
func GetTime(key string) time.Time { return v.GetTime(key) }
func (v *viper) GetTime(key string) time.Time {
return cast.ToTime(v.Get(key))
}
func GetStringSlice(key string) []string { return v.GetStringSlice(key) }
func (v *viper) GetStringSlice(key string) []string {
return cast.ToStringSlice(v.Get(key))
}
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))
}
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))
}
// Takes a single key and marshals it into a Struct
func MarshalKey(key string, rawVal interface{}) error { return v.MarshalKey(key, rawVal) }
func (v *viper) MarshalKey(key string, rawVal interface{}) error {
return mapstructure.Decode(v.Get(key), rawVal)
}
// Marshals the config into a Struct
func Marshal(rawVal interface{}) error { return v.Marshal(rawVal) }
func (v *viper) Marshal(rawVal interface{}) error {
err := mapstructure.Decode(v.defaults, rawVal)
if err != nil {
return err
}
err = mapstructure.Decode(v.config, rawVal)
if err != nil {
return err
}
err = mapstructure.Decode(v.override, rawVal)
if err != nil {
return err
}
err = mapstructure.Decode(v.kvstore, rawVal)
if err != nil {
return err
}
v.insensativiseMaps()
return nil
}
// 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 BindPFlag(key string, flag *pflag.Flag) (err error) { return v.BindPFlag(key, flag) }
func (v *viper) BindPFlag(key string, flag *pflag.Flag) (err error) {
if flag == nil {
return fmt.Errorf("flag for %q is nil", key)
}
v.pflags[strings.ToLower(key)] = flag
switch flag.Value.Type() {
case "int", "int8", "int16", "int32", "int64":
SetDefault(key, cast.ToInt(flag.Value.String()))
case "bool":
SetDefault(key, cast.ToBool(flag.Value.String()))
default:
SetDefault(key, flag.Value.String())
}
return nil
}
// 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.
// EnvPrefix will be used when set when env name is not provided.
func BindEnv(input ...string) (err error) { return v.BindEnv(input...) }
func (v *viper) BindEnv(input ...string) (err error) {
var key, envkey string
if len(input) == 0 {
return fmt.Errorf("BindEnv missing key to bind to")
}
key = strings.ToLower(input[0])
if len(input) == 1 {
envkey = v.mergeWithEnvPrefix(key)
} else {
envkey = input[1]
}
v.env[key] = envkey
return nil
}
// Given a key, find the value
// Viper will check in the following order:
// flag, env, config file, key/value store, default
// Viper will check to see if an alias exists first
func (v *viper) find(key string) interface{} {
var val interface{}
var exists bool
var file string
// if the requested key is an alias, then return the proper key
key = v.realKey(key)
// PFlag Override first
flag, exists := v.pflags[key]
if exists {
if flag.Changed {
jww.TRACE.Println(key, "found in override (via pflag):", val)
return flag.Value.String()
}
}
val, exists = v.override[key]
if exists {
jww.TRACE.Println(key, "found in override:", val)
return val
}
if v.automaticEnvApplied {
// even if it hasn't been registered, if automaticEnv is used,
// check any Get request
if val = os.Getenv(v.mergeWithEnvPrefix(key)); val != "" {
jww.TRACE.Println(key, "found in environment with val:", val)
return val
}
}
envkey, exists := v.env[key]
if exists {
jww.TRACE.Println(key, "registered as env var", envkey)
if val = os.Getenv(envkey); val != "" {
jww.TRACE.Println(envkey, "found in environment with val:", val)
return val
} else {
jww.TRACE.Println(envkey, "env value unset:")
}
}
val, exists = v.config[key]
if exists {
jww.TRACE.Println(key, "found in config:", val)
return val
}
if( v.cascadeConfigurations) {
//cascade down the rest of the files
val, exists, file = v.findCascading(key)
if exists {
jww.TRACE.Printf("%s found in config: %s (%s)", key, val, file)
return val
}
}
val, exists = v.kvstore[key]
if exists {
jww.TRACE.Println(key, "found in key/value store:", val)
return val
}
val, exists = v.defaults[key]
if exists {
jww.TRACE.Println(key, "found in defaults:", val)
return val
}
return nil
}
func (v *viper) findCascading(key string) (interface{}, bool, string) {
if( v.cascadingConfigs != nil ){
for file,config := range v.cascadingConfigs {
result := config[key]
if( result != nil ){
return result,true,file
}
}
}
v.cascadingConfigs = make(map[string]map[string]interface{})
configFiles := v.findAllConfigFiles()
for _, configFile := range configFiles {
if(v.cascadingConfigs[configFile] != nil){
//already cached
continue
}
jww.TRACE.Printf("Looking in %s for key %s",configFile,key)
file, err := ioutil.ReadFile(configFile)
if err != nil {
jww.ERROR.Print(err)
continue
}
jww.TRACE.Printf("marshalling %s for cascading",configFile)
var config = make(map[string]interface{})
marshallConfigReader(bytes.NewReader(file), config, filepath.Ext(configFile)[1:])
v.cascadingConfigs[configFile] = config
result := config[key]
if( result != nil){
return result,true,configFile
}
}
return "", false, ""
}
// Check to see if the key has been set in any of the data locations
func IsSet(key string) bool { return v.IsSet(key) }
func (v *viper) IsSet(key string) bool {
t := v.Get(key)
return t != nil
}
// Have viper check ENV variables for all
// keys set in config, default & flags
func AutomaticEnv() { v.AutomaticEnv() }
func (v *viper) AutomaticEnv() {
v.automaticEnvApplied = true
}
// Aliases provide another accessor for the same key.
// This enables one to change a name without breaking the application
func RegisterAlias(alias string, key string) { v.RegisterAlias(alias, key) }
func (v *viper) RegisterAlias(alias string, key string) {
v.registerAlias(alias, strings.ToLower(key))
}
func (v *viper) registerAlias(alias string, key string) {
alias = strings.ToLower(alias)
if alias != key && alias != v.realKey(key) {
_, exists := v.aliases[alias]
if !exists {
// if we alias something that exists in one of the maps to another
// name, we'll never be able to get that value using the original
// name, so move the config value to the new realkey.
if val, ok := v.config[alias]; ok {
delete(v.config, alias)
v.config[key] = val
}
if val, ok := v.kvstore[alias]; ok {
delete(v.kvstore, alias)
v.kvstore[key] = val
}
if val, ok := v.defaults[alias]; ok {
delete(v.defaults, alias)
v.defaults[key] = val
}
if val, ok := v.override[alias]; ok {
delete(v.override, alias)
v.override[key] = val
}
v.aliases[alias] = key
}
} else {
jww.WARN.Println("Creating circular reference alias", alias, key, v.realKey(key))
}
}
func (v *viper) realKey(key string) string {
newkey, exists := v.aliases[key]
if exists {
jww.DEBUG.Println("Alias", key, "to", newkey)
return v.realKey(newkey)
} else {
return key
}
}
// Check to see if the given key (or an alias) is in the config file
func InConfig(key string) bool { return v.InConfig(key) }
func (v *viper) InConfig(key string) bool {
// if the requested key is an alias, then return the proper key
key = v.realKey(key)
_, exists := v.config[key]
return exists
}
// Set the default value for this key.
// Default only used when no value is provided by the user via flag, config or ENV.
func SetDefault(key string, value interface{}) { v.SetDefault(key, value) }
func (v *viper) SetDefault(key string, value interface{}) {
// If alias passed in, then set the proper default
key = v.realKey(strings.ToLower(key))
v.defaults[key] = value
}
// The user provided value (via flag)
// Will be used instead of values obtained via
// 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
key = v.realKey(strings.ToLower(key))
v.override[key] = value
}
// Viper will discover and load the configuration file from disk
// and key/value stores, searching in one of the defined paths.
func ReadInConfig() error { return v.ReadInConfig() }
func (v *viper) ReadInConfig() error {
jww.INFO.Println("Attempting to read in config file")
if !stringInSlice(v.getConfigType(), SupportedExts) {
return UnsupportedConfigError(v.getConfigType())
}
file, err := ioutil.ReadFile(v.getConfigFile())
if err != nil {
return err
}
v.marshalReader(bytes.NewReader(file), v.config)
return nil
}
func ReadRemoteConfig() error { return v.ReadRemoteConfig() }
func (v *viper) ReadRemoteConfig() error {
err := v.getKeyValueConfig()
if err != nil {
return err
}
return nil
}
// Marshall a Reader into a map
// Should probably be an unexported function
func marshalReader(in io.Reader, c map[string]interface{}) { v.marshalReader(in, c) }
func (v *viper) marshalReader(in io.Reader, c map[string]interface{}) {
marshallConfigReader(in, c, v.getConfigType())
}
func (v *viper) insensativiseMaps() {
insensativiseMap(v.config)
insensativiseMap(v.defaults)
insensativiseMap(v.override)
insensativiseMap(v.kvstore)
}
// retrieve the first found remote configuration
func (v *viper) getKeyValueConfig() error {
for _, rp := range v.remoteProviders {
val, err := v.getRemoteConfig(rp)
if err != nil {
continue
}
v.kvstore = val
return nil
}
return RemoteConfigError("No Files Found")
}
func (v *viper) getRemoteConfig(provider *remoteProvider) (map[string]interface{}, error) {
var cm crypt.ConfigManager
var err error
if provider.secretKeyring != "" {
kr, err := os.Open(provider.secretKeyring)
defer kr.Close()
if err != nil {
return nil, err
}
if provider.provider == "etcd" {
cm, err = crypt.NewEtcdConfigManager([]string{provider.endpoint}, kr)
} else {
cm, err = crypt.NewConsulConfigManager([]string{provider.endpoint}, kr)
}
} else {
if provider.provider == "etcd" {
cm, err = crypt.NewStandardEtcdConfigManager([]string{provider.endpoint})
} else {
cm, err = crypt.NewStandardConsulConfigManager([]string{provider.endpoint})
}
}
if err != nil {
return nil, err
}
b, err := cm.Get(provider.path)
if err != nil {
return nil, err
}
reader := bytes.NewReader(b)
v.marshalReader(reader, v.kvstore)
return v.kvstore, err
}
// Return all keys regardless where they are set
func AllKeys() []string { return v.AllKeys() }
func (v *viper) AllKeys() []string {
m := map[string]struct{}{}
for key, _ := range v.defaults {
m[key] = struct{}{}
}
for key, _ := range v.config {
m[key] = struct{}{}
}
for key, _ := range v.kvstore {
m[key] = struct{}{}
}
for key, _ := range v.override {
m[key] = struct{}{}
}
a := []string{}
for x, _ := range m {
a = append(a, x)
}
return a
}
// Return all settings as a map[string]interface{}
func AllSettings() map[string]interface{} { return v.AllSettings() }
func (v *viper) AllSettings() map[string]interface{} {
m := map[string]interface{}{}
for _, x := range v.AllKeys() {
m[x] = v.Get(x)
}
return m
}
// Name for the config file.
// Does not include extension.
func SetConfigName(in string) { v.SetConfigName(in) }
func (v *viper) SetConfigName(in string) {
if in != "" {
v.configName = in
}
}
func SetConfigType(in string) { v.SetConfigType(in) }
func (v *viper) SetConfigType(in string) {
if in != "" {
v.configType = in
}
}
func (v *viper) getConfigType() string {
if v.configType != "" {
return v.configType
}
cf := v.getConfigFile()
ext := filepath.Ext(cf)
if len(ext) > 1 {
return ext[1:]
} else {
return ""
}
}
func (v *viper) getConfigFile() string {
// if explicitly set, then use it
if v.configFile != "" {
return v.configFile
}
cf, err := v.findConfigFile()
if err != nil {
return ""
}
v.configFile = cf
return v.getConfigFile()
}
func (v *viper) searchInPath(in string) (filename string) {
jww.DEBUG.Println("Searching for config in ", in)
for _, ext := range SupportedExts {
jww.DEBUG.Println("Checking for", filepath.Join(in, v.configName+"."+ext))
if b, _ := exists(filepath.Join(in, v.configName+"."+ext)); b {
jww.DEBUG.Println("Found: ", filepath.Join(in, v.configName+"."+ext))
return filepath.Join(in, v.configName+"."+ext)
}
}
return ""
}
// search all configPaths for any config file.
// Returns the first path that exists (and is a config file)
func (v *viper) findConfigFile() (string, error) {
jww.INFO.Println("Searching for config in ", v.configPaths)
var validFiles = v.findAllConfigFiles()
if len(validFiles) == 0 {
return "", fmt.Errorf("config file not found in: %s", v.configPaths)
}
return validFiles[0], nil
}
func (v *viper) findAllConfigFiles() []string {
var validFiles []string
for _, cp := range v.configPaths {
file := v.searchInPath(cp)
if file != "" {
jww.TRACE.Println("Found config file in: %s",file)
validFiles = append(validFiles, file)
}
}
cwd, _ := findCWD()
file := v.searchInPath(cwd)
if file != "" {
validFiles = append(validFiles, file)
}
// try the current working directory
wd, _ := os.Getwd()
file = v.searchInPath(wd)
if file != "" {
validFiles = append(validFiles, file)
}
return validFiles
}
func Debug() { v.Debug() }
func (v *viper) Debug() {
fmt.Println("Config:")
pretty.Println(v.config)
fmt.Println("Key/Value Store:")
pretty.Println(v.kvstore)
fmt.Println("Env:")
pretty.Println(v.env)
fmt.Println("Defaults:")
pretty.Println(v.defaults)
fmt.Println("Override:")
pretty.Println(v.override)
fmt.Println("Aliases:")
pretty.Println(v.aliases)
}