plugin/forward: Split setup to reuse it from external plugins (#2034)

plugin/forward/setup.go

@@ -13,6 +13,7 @@ import (
 	pkgtls "github.com/coredns/coredns/plugin/pkg/tls"
 
 	"github.com/mholt/caddy"
+	"github.com/mholt/caddy/caddyfile"
 )
 
 func init() {
@@ -70,16 +71,29 @@ func (f *Forward) OnShutdown() error {
 func (f *Forward) Close() { f.OnShutdown() }
 
 func parseForward(c *caddy.Controller) (*Forward, error) {
-	f := New()
-
-	protocols := map[int]int{}
-
-	i := 0
+	var (
+		f   *Forward
+		err error
+		i   int
+	)
 	for c.Next() {
 		if i > 0 {
 			return nil, plugin.ErrOnce
 		}
 		i++
+		f, err = ParseForwardStanza(&c.Dispenser)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return f, nil
+}
+
+// ParseForwardStanza parses one forward stanza
+func ParseForwardStanza(c *caddyfile.Dispenser) (*Forward, error) {
+	f := New()
+
+	protocols := map[int]int{}
 
 	if !c.Args(&f.from) {
 		return f, c.ArgErr()
@@ -133,7 +147,6 @@ func parseForward(c *caddy.Controller) (*Forward, error) {
 			return f, err
 		}
 	}
-	}
 
 	if f.tlsServerName != "" {
 		f.tlsConfig.ServerName = f.tlsServerName
@@ -148,7 +161,7 @@ func parseForward(c *caddy.Controller) (*Forward, error) {
 	return f, nil
 }
 
-func parseBlock(c *caddy.Controller, f *Forward) error {
+func parseBlock(c *caddyfile.Dispenser, f *Forward) error {
 	switch c.Val() {
 	case "except":
 		ignore := c.RemainingArgs()