add local plugin (#4262)

* add local plugin

See: #4260

Signed-off-by: Miek Gieben <miek@miek.nl>

* stickler bot

Signed-off-by: Miek Gieben <miek@miek.nl>

* See Also

Signed-off-by: Miek Gieben <miek@miek.nl>

plugin/local/setup.go

@@ -0,0 +1,20 @@
+package local
+
+import (
+	"github.com/coredns/caddy"
+	"github.com/coredns/coredns/core/dnsserver"
+	"github.com/coredns/coredns/plugin"
+)
+
+func init() { plugin.Register("local", setup) }
+
+func setup(c *caddy.Controller) error {
+	l := Local{}
+
+	dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
+		l.Next = next
+		return l
+	})
+
+	return nil
+}