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package main
import (
"fmt"
"log"
"strings"
"github.com/knadh/koanf/parsers/json"
"github.com/knadh/koanf/providers/env"
"github.com/knadh/koanf/providers/file"
"github.com/knadh/koanf/v2"
)
var k = koanf.New(".")
func main() {
// Load JSON config.
if err := k.Load(file.Provider("mock/mock.json"), json.Parser()); err != nil {
log.Fatalf("error loading config: %v", err)
}
// Load environment variables and merge into the loaded config.
// "MYVAR" is the prefix to filter the env vars by.
// "." is the delimiter used to represent the key hierarchy in env vars.
// The (optional, or can be nil) function can be used to transform
// the env var names, for instance, to lowercase them.
//
// For example, env vars: MYVAR_TYPE and MYVAR_PARENT1_CHILD1_NAME
// will be merged into the "type" and the nested "parent1.child1.name"
// keys in the config file here as we lowercase the key,
// replace `_` with `.` and strip the MYVAR_ prefix so that
// only "parent1.child1.name" remains.
k.Load(env.Provider("MYVAR_", ".", func(s string) string {
return strings.Replace(strings.ToLower(
strings.TrimPrefix(s, "MYVAR_")), "_", ".", -1)
}), nil)
// Use ProviderWithValue() to process both keys and values into types other than strings,
// for example, turn space separated env vars into slices.
// k.Load(env.ProviderWithValue("MYVAR_", ".", func(s string, v string) (string, interface{}) {
// // Strip out the MYVAR_ prefix and lowercase and get the key while also replacing
// // the _ character with . in the key (koanf delimeter).
// key := strings.Replace(strings.ToLower(strings.TrimPrefix(s, "MYVAR_")), "_", ".", -1)
// // If there is a space in the value, split the value into a slice by the space.
// if strings.Contains(v, " ") {
// return key, strings.Split(v, " ")
// }
// // Otherwise, return the plain string.
// return key, v
// }), nil)
fmt.Println("name is = ", k.String("parent1.child1.name"))
}
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