feat:error returning connection in provider method

[lyonnee]

#210
As @jxsl13 says here, it is necessary to return error in the Provider method. this allows the caller to know the reason for the connection failure

[knadh]

Can you also update the instances in https://github.com/knadh/koanf/blob/master/examples/complex-etcd/main.go?

[lyonnee]

Can you also update the instances in https://github.com/knadh/koanf/blob/master/examples/complex-etcd/main.go?

This instance has been modified

[knadh]

clientv3.Config{
   Endpoints:   cfg.Endpoints,
   DialTimeout: cfg.DialTimeout,
}

I think it's best if we pass this etcd config also to the provider config. Otherwise, we're rendering many etcd config options inaccessible.

type Config struct {
        ClientConfig clientv3.Config

	// prefix request option
	Prefix bool

	// limit request option
	Limit bool

	// number of limited pairs
	NLimit int64

	// key, key with prefix, etc.
	Key string
}

[lyonnee]

type Etcd struct {
	client *clientv3.Client
	cfg    Config
}

The configuration information is already stored in this structure

// /providers/etcd/etcd.go
func (e *Etcd) getConf(){
	eps := e.cfg.Endpoints
	dt := e.cfg.DialTimeout

	fmt.Println(eps)
	fmt.Println(dt)
}

[knadh]

etcd/clientv3.Config has a lot more options than just Endpoints and DialTimeout. The provider config can accept the whole clientv3.Config as is.

[rhnvrm]

Maybe, can also consider embedding clientv3.Config and still allow the extra configs like prefix, limit, nlimit, key needed by the koanf provider?

diff --git a/providers/etcd/etcd.go b/providers/etcd/etcd.go
index c75da16..db6f3b9 100644
--- a/providers/etcd/etcd.go
+++ b/providers/etcd/etcd.go
@@ -3,18 +3,11 @@ package etcd
 import (
 	"context"
 	"errors"
-	"time"
 
 	clientv3 "go.etcd.io/etcd/client/v3"
 )
 
 type Config struct {
-	// etcd endpoints
-	Endpoints []string
-
-	// timeout
-	DialTimeout time.Duration
-
 	// prefix request option
 	Prefix bool
 
@@ -26,6 +19,8 @@ type Config struct {
 
 	// key, key with prefix, etc.
 	Key string
+
+	clientv3.Config
 }
 
 // Etcd implements the etcd config provider.
@@ -36,12 +31,7 @@ type Etcd struct {
 
 // Provider returns a provider that takes etcd config.
 func Provider(cfg Config) *Etcd {
-	eCfg := clientv3.Config{
-		Endpoints:   cfg.Endpoints,
-		DialTimeout: cfg.DialTimeout,
-	}
-
-	c, err := clientv3.New(eCfg)
+	c, err := clientv3.New(cfg.Config)
 	if err != nil {
 		return nil
 	}

[lyonnee]

etcd/clientv3.Config has a lot more options than just Endpoints and DialTimeout. The provider config can accept the whole clientv3.Config as is.

Sorry, I didn't understand your meaning before. I have made modifications