forked from ebhomengo/niki
87 lines
2.2 KiB
Go
87 lines
2.2 KiB
Go
package config
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import (
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"log"
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"strings"
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"github.com/knadh/koanf"
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"github.com/knadh/koanf/parsers/yaml"
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"github.com/knadh/koanf/providers/env"
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"github.com/knadh/koanf/providers/file"
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"github.com/knadh/koanf/providers/structs"
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)
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const (
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defaultPrefix = "EB_"
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defaultDelimiter = "."
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defaultSeparator = "__"
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defaultYamlFilePath = "config.yml"
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)
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var c Config
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type Option struct {
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Prefix string
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Delimiter string
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Separator string
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YamlFilePath string
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CallbackEnv func(string) string
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}
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// our environment variables must prefix with `EB_`
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// for nested .env should use `__` aka: EB__DB__HOST.
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func defaultCallbackEnv(source string) string {
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base := strings.ToLower(strings.TrimPrefix(source, defaultPrefix))
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return strings.ReplaceAll(base, defaultSeparator, defaultDelimiter)
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}
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func init() {
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k := koanf.New(defaultDelimiter)
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// load default configuration from Default function
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if err := k.Load(structs.Provider(Default(), "koanf"), nil); err != nil {
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log.Fatalf("error loading default config: %s", err)
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}
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// load configuration from yaml file
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if err := k.Load(file.Provider(defaultYamlFilePath), yaml.Parser()); err != nil {
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log.Printf("error loading config from `config.yml` file: %s", err)
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}
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// load from environment variable
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if err := k.Load(env.Provider(defaultPrefix, defaultDelimiter, defaultCallbackEnv), nil); err != nil {
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log.Printf("error loading environment variables: %s", err)
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}
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if err := k.Unmarshal("", &c); err != nil {
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log.Fatalf("error unmarshaling config: %s", err)
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}
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}
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func C() Config {
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return c
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}
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func New(opt Option) Config {
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k := koanf.New(opt.Separator)
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if err := k.Load(structs.Provider(Default(), "koanf"), nil); err != nil {
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log.Fatalf("error loading default config: %s", err)
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}
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if err := k.Load(file.Provider(opt.YamlFilePath), yaml.Parser()); err != nil {
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log.Printf("error loading config from `config.yml` file: %s", err)
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}
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if err := k.Load(env.Provider(opt.Prefix, opt.Delimiter, opt.CallbackEnv), nil); err != nil {
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log.Printf("error loading environment variables: %s", err)
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}
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if err := k.Unmarshal("", &c); err != nil {
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log.Fatalf("error unmarshaling config: %s", err)
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}
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return c
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}
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