plugin/loadbalance: add parse and tests (#1947)

Automatically submitted.

plugin/loadbalance/setup.go

@@ -1,6 +1,8 @@
 package loadbalance
 
 import (
+	"fmt"
+
 	"github.com/coredns/coredns/core/dnsserver"
 	"github.com/coredns/coredns/plugin"
 	clog "github.com/coredns/coredns/plugin/pkg/log"
@@ -18,8 +20,9 @@ func init() {
 }
 
 func setup(c *caddy.Controller) error {
-	for c.Next() {
-		// TODO(miek): block and option parsing
+	err := parse(c)
+	if err != nil {
+		return plugin.Error("loadbalance", err)
 	}
 
 	dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
@@ -28,3 +31,20 @@ func setup(c *caddy.Controller) error {
 
 	return nil
 }
+
+func parse(c *caddy.Controller) error {
+	for c.Next() {
+		args := c.RemainingArgs()
+		switch len(args) {
+		case 0:
+			return nil
+		case 1:
+			if args[0] != "round_robin" {
+				return fmt.Errorf("unknown policy: %s", args[0])
+
+			}
+			return nil
+		}
+	}
+	return c.ArgErr()
+}