added rpc clients management

rpc/clients.go

@@ -0,0 +1,39 @@
+package rpc
+
+import (
+	"errors"
+
+	"github.com/hashicorp/go-multierror"
+)
+
+var ErrorNoMoreClient = errors.New("no more clients")
+
+type Clients[C any] struct {
+	clients []C
+	next    int
+}
+
+func (c *Clients[C]) Next() (client C, err error) {
+	if len(c.clients) <= c.next {
+		return client, ErrorNoMoreClient
+	}
+	client = c.clients[c.next]
+	c.next++
+	return client, nil
+}
+
+func WithClients[C any, V any](clients *Clients[C], f func(C) (v V, err error)) (v V, err error) {
+	var errs error
+	for {
+		client, err := clients.Next()
+		if err != nil {
+			return v, err
+		}
+		v, err := f(client)
+		if err != nil {
+			errs = multierror.Append(errs, err)
+			continue
+		}
+		return v, nil
+	}
+}