541 lines
13 KiB
Go
541 lines
13 KiB
Go
package env
|
|
|
|
import (
|
|
"encoding"
|
|
"fmt"
|
|
"net/url"
|
|
"os"
|
|
"reflect"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
"unicode"
|
|
)
|
|
|
|
// nolint: gochecknoglobals
|
|
var (
|
|
defaultBuiltInParsers = map[reflect.Kind]ParserFunc{
|
|
reflect.Bool: func(v string) (interface{}, error) {
|
|
return strconv.ParseBool(v)
|
|
},
|
|
reflect.String: func(v string) (interface{}, error) {
|
|
return v, nil
|
|
},
|
|
reflect.Int: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseInt(v, 10, 32)
|
|
return int(i), err
|
|
},
|
|
reflect.Int16: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseInt(v, 10, 16)
|
|
return int16(i), err
|
|
},
|
|
reflect.Int32: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseInt(v, 10, 32)
|
|
return int32(i), err
|
|
},
|
|
reflect.Int64: func(v string) (interface{}, error) {
|
|
return strconv.ParseInt(v, 10, 64)
|
|
},
|
|
reflect.Int8: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseInt(v, 10, 8)
|
|
return int8(i), err
|
|
},
|
|
reflect.Uint: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseUint(v, 10, 32)
|
|
return uint(i), err
|
|
},
|
|
reflect.Uint16: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseUint(v, 10, 16)
|
|
return uint16(i), err
|
|
},
|
|
reflect.Uint32: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseUint(v, 10, 32)
|
|
return uint32(i), err
|
|
},
|
|
reflect.Uint64: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseUint(v, 10, 64)
|
|
return i, err
|
|
},
|
|
reflect.Uint8: func(v string) (interface{}, error) {
|
|
i, err := strconv.ParseUint(v, 10, 8)
|
|
return uint8(i), err
|
|
},
|
|
reflect.Float64: func(v string) (interface{}, error) {
|
|
return strconv.ParseFloat(v, 64)
|
|
},
|
|
reflect.Float32: func(v string) (interface{}, error) {
|
|
f, err := strconv.ParseFloat(v, 32)
|
|
return float32(f), err
|
|
},
|
|
}
|
|
)
|
|
|
|
func defaultTypeParsers() map[reflect.Type]ParserFunc {
|
|
return map[reflect.Type]ParserFunc{
|
|
reflect.TypeOf(url.URL{}): func(v string) (interface{}, error) {
|
|
u, err := url.Parse(v)
|
|
if err != nil {
|
|
return nil, newParseValueError("unable to parse URL", err)
|
|
}
|
|
return *u, nil
|
|
},
|
|
reflect.TypeOf(time.Nanosecond): func(v string) (interface{}, error) {
|
|
s, err := time.ParseDuration(v)
|
|
if err != nil {
|
|
return nil, newParseValueError("unable to parse duration", err)
|
|
}
|
|
return s, err
|
|
},
|
|
}
|
|
}
|
|
|
|
// ParserFunc defines the signature of a function that can be used within `CustomParsers`.
|
|
type ParserFunc func(v string) (interface{}, error)
|
|
|
|
// OnSetFn is a hook that can be run when a value is set.
|
|
type OnSetFn func(tag string, value interface{}, isDefault bool)
|
|
|
|
// Options for the parser.
|
|
type Options struct {
|
|
// Environment keys and values that will be accessible for the service.
|
|
Environment map[string]string
|
|
|
|
// TagName specifies another tagname to use rather than the default env.
|
|
TagName string
|
|
|
|
// RequiredIfNoDef automatically sets all env as required if they do not
|
|
// declare 'envDefault'.
|
|
RequiredIfNoDef bool
|
|
|
|
// OnSet allows to run a function when a value is set.
|
|
OnSet OnSetFn
|
|
|
|
// Prefix define a prefix for each key.
|
|
Prefix string
|
|
|
|
// UseFieldNameByDefault defines whether or not env should use the field
|
|
// name by default if the `env` key is missing.
|
|
UseFieldNameByDefault bool
|
|
|
|
// Sets to true if we have already configured once.
|
|
configured bool
|
|
}
|
|
|
|
// configure will do the basic configurations and defaults.
|
|
func configure(opts []Options) []Options {
|
|
// If we have already configured the first item
|
|
// of options will have been configured set to true.
|
|
if len(opts) > 0 && opts[0].configured {
|
|
return opts
|
|
}
|
|
|
|
// Created options with defaults.
|
|
opt := Options{
|
|
TagName: "env",
|
|
Environment: toMap(os.Environ()),
|
|
configured: true,
|
|
}
|
|
|
|
// Loop over all opts structs and set
|
|
// to opt if value is not default/empty.
|
|
for _, item := range opts {
|
|
if item.Environment != nil {
|
|
opt.Environment = item.Environment
|
|
}
|
|
if item.TagName != "" {
|
|
opt.TagName = item.TagName
|
|
}
|
|
if item.OnSet != nil {
|
|
opt.OnSet = item.OnSet
|
|
}
|
|
if item.Prefix != "" {
|
|
opt.Prefix = item.Prefix
|
|
}
|
|
opt.UseFieldNameByDefault = item.UseFieldNameByDefault
|
|
opt.RequiredIfNoDef = item.RequiredIfNoDef
|
|
}
|
|
|
|
return []Options{opt}
|
|
}
|
|
|
|
func getOnSetFn(opts []Options) OnSetFn {
|
|
return opts[0].OnSet
|
|
}
|
|
|
|
// getTagName returns the tag name.
|
|
func getTagName(opts []Options) string {
|
|
return opts[0].TagName
|
|
}
|
|
|
|
// getEnvironment returns the environment map.
|
|
func getEnvironment(opts []Options) map[string]string {
|
|
return opts[0].Environment
|
|
}
|
|
|
|
// Parse parses a struct containing `env` tags and loads its values from
|
|
// environment variables.
|
|
func Parse(v interface{}, opts ...Options) error {
|
|
return ParseWithFuncs(v, map[reflect.Type]ParserFunc{}, opts...)
|
|
}
|
|
|
|
// ParseWithFuncs is the same as `Parse` except it also allows the user to pass
|
|
// in custom parsers.
|
|
func ParseWithFuncs(v interface{}, funcMap map[reflect.Type]ParserFunc, opts ...Options) error {
|
|
opts = configure(opts)
|
|
|
|
ptrRef := reflect.ValueOf(v)
|
|
if ptrRef.Kind() != reflect.Ptr {
|
|
return newAggregateError(NotStructPtrError{})
|
|
}
|
|
ref := ptrRef.Elem()
|
|
if ref.Kind() != reflect.Struct {
|
|
return newAggregateError(NotStructPtrError{})
|
|
}
|
|
parsers := defaultTypeParsers()
|
|
for k, v := range funcMap {
|
|
parsers[k] = v
|
|
}
|
|
|
|
return doParse(ref, parsers, opts)
|
|
}
|
|
|
|
func doParse(ref reflect.Value, funcMap map[reflect.Type]ParserFunc, opts []Options) error {
|
|
refType := ref.Type()
|
|
|
|
var agrErr AggregateError
|
|
|
|
for i := 0; i < refType.NumField(); i++ {
|
|
refField := ref.Field(i)
|
|
refTypeField := refType.Field(i)
|
|
|
|
if err := doParseField(refField, refTypeField, funcMap, opts); err != nil {
|
|
if val, ok := err.(AggregateError); ok {
|
|
agrErr.Errors = append(agrErr.Errors, val.Errors...)
|
|
} else {
|
|
agrErr.Errors = append(agrErr.Errors, err)
|
|
}
|
|
}
|
|
}
|
|
|
|
if len(agrErr.Errors) == 0 {
|
|
return nil
|
|
}
|
|
|
|
return agrErr
|
|
}
|
|
|
|
func doParseField(refField reflect.Value, refTypeField reflect.StructField, funcMap map[reflect.Type]ParserFunc, opts []Options) error {
|
|
if !refField.CanSet() {
|
|
return nil
|
|
}
|
|
if reflect.Ptr == refField.Kind() && !refField.IsNil() {
|
|
return ParseWithFuncs(refField.Interface(), funcMap, optsWithPrefix(refTypeField, opts)...)
|
|
}
|
|
if reflect.Struct == refField.Kind() && refField.CanAddr() && refField.Type().Name() == "" {
|
|
return ParseWithFuncs(refField.Addr().Interface(), funcMap, optsWithPrefix(refTypeField, opts)...)
|
|
}
|
|
value, err := get(refTypeField, opts)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if value != "" {
|
|
return set(refField, refTypeField, value, funcMap)
|
|
}
|
|
|
|
if reflect.Struct == refField.Kind() {
|
|
return doParse(refField, funcMap, optsWithPrefix(refTypeField, opts))
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
const underscore rune = '_'
|
|
|
|
func toEnvName(input string) string {
|
|
var output []rune
|
|
for i, c := range input {
|
|
if i > 0 && output[i-1] != underscore && c != underscore && unicode.ToUpper(c) == c {
|
|
output = append(output, underscore)
|
|
}
|
|
output = append(output, unicode.ToUpper(c))
|
|
}
|
|
return string(output)
|
|
}
|
|
|
|
func get(field reflect.StructField, opts []Options) (val string, err error) {
|
|
var exists bool
|
|
var isDefault bool
|
|
var loadFile bool
|
|
var unset bool
|
|
var notEmpty bool
|
|
|
|
required := opts[0].RequiredIfNoDef
|
|
prefix := opts[0].Prefix
|
|
ownKey, tags := parseKeyForOption(field.Tag.Get(getTagName(opts)))
|
|
if ownKey == "" && opts[0].UseFieldNameByDefault {
|
|
ownKey = toEnvName(field.Name)
|
|
}
|
|
key := prefix + ownKey
|
|
for _, tag := range tags {
|
|
switch tag {
|
|
case "":
|
|
continue
|
|
case "file":
|
|
loadFile = true
|
|
case "required":
|
|
required = true
|
|
case "unset":
|
|
unset = true
|
|
case "notEmpty":
|
|
notEmpty = true
|
|
default:
|
|
return "", newNoSupportedTagOptionError(tag)
|
|
}
|
|
}
|
|
expand := strings.EqualFold(field.Tag.Get("envExpand"), "true")
|
|
defaultValue, defExists := field.Tag.Lookup("envDefault")
|
|
val, exists, isDefault = getOr(key, defaultValue, defExists, getEnvironment(opts))
|
|
|
|
if expand {
|
|
val = os.ExpandEnv(val)
|
|
}
|
|
|
|
if unset {
|
|
defer os.Unsetenv(key)
|
|
}
|
|
|
|
if required && !exists && len(ownKey) > 0 {
|
|
return "", newEnvVarIsNotSet(key)
|
|
}
|
|
|
|
if notEmpty && val == "" {
|
|
return "", newEmptyEnvVarError(key)
|
|
}
|
|
|
|
if loadFile && val != "" {
|
|
filename := val
|
|
val, err = getFromFile(filename)
|
|
if err != nil {
|
|
return "", newLoadFileContentError(filename, key, err)
|
|
}
|
|
}
|
|
|
|
if onSetFn := getOnSetFn(opts); onSetFn != nil {
|
|
onSetFn(key, val, isDefault)
|
|
}
|
|
return val, err
|
|
}
|
|
|
|
// split the env tag's key into the expected key and desired option, if any.
|
|
func parseKeyForOption(key string) (string, []string) {
|
|
opts := strings.Split(key, ",")
|
|
return opts[0], opts[1:]
|
|
}
|
|
|
|
func getFromFile(filename string) (value string, err error) {
|
|
b, err := os.ReadFile(filename)
|
|
return string(b), err
|
|
}
|
|
|
|
func getOr(key, defaultValue string, defExists bool, envs map[string]string) (string, bool, bool) {
|
|
value, exists := envs[key]
|
|
switch {
|
|
case (!exists || key == "") && defExists:
|
|
return defaultValue, true, true
|
|
case exists && value == "" && defExists:
|
|
return defaultValue, true, true
|
|
case !exists:
|
|
return "", false, false
|
|
}
|
|
|
|
return value, true, false
|
|
}
|
|
|
|
func set(field reflect.Value, sf reflect.StructField, value string, funcMap map[reflect.Type]ParserFunc) error {
|
|
if tm := asTextUnmarshaler(field); tm != nil {
|
|
if err := tm.UnmarshalText([]byte(value)); err != nil {
|
|
return newParseError(sf, err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
typee := sf.Type
|
|
fieldee := field
|
|
if typee.Kind() == reflect.Ptr {
|
|
typee = typee.Elem()
|
|
fieldee = field.Elem()
|
|
}
|
|
|
|
parserFunc, ok := funcMap[typee]
|
|
if ok {
|
|
val, err := parserFunc(value)
|
|
if err != nil {
|
|
return newParseError(sf, err)
|
|
}
|
|
|
|
fieldee.Set(reflect.ValueOf(val))
|
|
return nil
|
|
}
|
|
|
|
parserFunc, ok = defaultBuiltInParsers[typee.Kind()]
|
|
if ok {
|
|
val, err := parserFunc(value)
|
|
if err != nil {
|
|
return newParseError(sf, err)
|
|
}
|
|
|
|
fieldee.Set(reflect.ValueOf(val).Convert(typee))
|
|
return nil
|
|
}
|
|
|
|
switch field.Kind() {
|
|
case reflect.Slice:
|
|
return handleSlice(field, value, sf, funcMap)
|
|
case reflect.Map:
|
|
return handleMap(field, value, sf, funcMap)
|
|
}
|
|
|
|
return newNoParserError(sf)
|
|
}
|
|
|
|
func handleSlice(field reflect.Value, value string, sf reflect.StructField, funcMap map[reflect.Type]ParserFunc) error {
|
|
separator := sf.Tag.Get("envSeparator")
|
|
if separator == "" {
|
|
separator = ","
|
|
}
|
|
parts := strings.Split(value, separator)
|
|
|
|
typee := sf.Type.Elem()
|
|
if typee.Kind() == reflect.Ptr {
|
|
typee = typee.Elem()
|
|
}
|
|
|
|
if _, ok := reflect.New(typee).Interface().(encoding.TextUnmarshaler); ok {
|
|
return parseTextUnmarshalers(field, parts, sf)
|
|
}
|
|
|
|
parserFunc, ok := funcMap[typee]
|
|
if !ok {
|
|
parserFunc, ok = defaultBuiltInParsers[typee.Kind()]
|
|
if !ok {
|
|
return newNoParserError(sf)
|
|
}
|
|
}
|
|
|
|
result := reflect.MakeSlice(sf.Type, 0, len(parts))
|
|
for _, part := range parts {
|
|
r, err := parserFunc(part)
|
|
if err != nil {
|
|
return newParseError(sf, err)
|
|
}
|
|
v := reflect.ValueOf(r).Convert(typee)
|
|
if sf.Type.Elem().Kind() == reflect.Ptr {
|
|
v = reflect.New(typee)
|
|
v.Elem().Set(reflect.ValueOf(r).Convert(typee))
|
|
}
|
|
result = reflect.Append(result, v)
|
|
}
|
|
field.Set(result)
|
|
return nil
|
|
}
|
|
|
|
func handleMap(field reflect.Value, value string, sf reflect.StructField, funcMap map[reflect.Type]ParserFunc) error {
|
|
keyType := sf.Type.Key()
|
|
keyParserFunc, ok := funcMap[keyType]
|
|
if !ok {
|
|
keyParserFunc, ok = defaultBuiltInParsers[keyType.Kind()]
|
|
if !ok {
|
|
return newNoParserError(sf)
|
|
}
|
|
}
|
|
|
|
elemType := sf.Type.Elem()
|
|
elemParserFunc, ok := funcMap[elemType]
|
|
if !ok {
|
|
elemParserFunc, ok = defaultBuiltInParsers[elemType.Kind()]
|
|
if !ok {
|
|
return newNoParserError(sf)
|
|
}
|
|
}
|
|
|
|
separator := sf.Tag.Get("envSeparator")
|
|
if separator == "" {
|
|
separator = ","
|
|
}
|
|
|
|
result := reflect.MakeMap(sf.Type)
|
|
for _, part := range strings.Split(value, separator) {
|
|
pairs := strings.Split(part, ":")
|
|
if len(pairs) != 2 {
|
|
return newParseError(sf, fmt.Errorf(`%q should be in "key:value" format`, part))
|
|
}
|
|
|
|
key, err := keyParserFunc(pairs[0])
|
|
if err != nil {
|
|
return newParseError(sf, err)
|
|
}
|
|
|
|
elem, err := elemParserFunc(pairs[1])
|
|
if err != nil {
|
|
return newParseError(sf, err)
|
|
}
|
|
|
|
result.SetMapIndex(reflect.ValueOf(key).Convert(keyType), reflect.ValueOf(elem).Convert(elemType))
|
|
}
|
|
|
|
field.Set(result)
|
|
return nil
|
|
}
|
|
|
|
func asTextUnmarshaler(field reflect.Value) encoding.TextUnmarshaler {
|
|
if reflect.Ptr == field.Kind() {
|
|
if field.IsNil() {
|
|
field.Set(reflect.New(field.Type().Elem()))
|
|
}
|
|
} else if field.CanAddr() {
|
|
field = field.Addr()
|
|
}
|
|
|
|
tm, ok := field.Interface().(encoding.TextUnmarshaler)
|
|
if !ok {
|
|
return nil
|
|
}
|
|
return tm
|
|
}
|
|
|
|
func parseTextUnmarshalers(field reflect.Value, data []string, sf reflect.StructField) error {
|
|
s := len(data)
|
|
elemType := field.Type().Elem()
|
|
slice := reflect.MakeSlice(reflect.SliceOf(elemType), s, s)
|
|
for i, v := range data {
|
|
sv := slice.Index(i)
|
|
kind := sv.Kind()
|
|
if kind == reflect.Ptr {
|
|
sv = reflect.New(elemType.Elem())
|
|
} else {
|
|
sv = sv.Addr()
|
|
}
|
|
tm := sv.Interface().(encoding.TextUnmarshaler)
|
|
if err := tm.UnmarshalText([]byte(v)); err != nil {
|
|
return newParseError(sf, err)
|
|
}
|
|
if kind == reflect.Ptr {
|
|
slice.Index(i).Set(sv)
|
|
}
|
|
}
|
|
|
|
field.Set(slice)
|
|
|
|
return nil
|
|
}
|
|
|
|
func optsWithPrefix(field reflect.StructField, opts []Options) []Options {
|
|
subOpts := make([]Options, len(opts))
|
|
copy(subOpts, opts)
|
|
if prefix := field.Tag.Get("envPrefix"); prefix != "" {
|
|
subOpts[0].Prefix += prefix
|
|
}
|
|
return subOpts
|
|
}
|