1 files changed, 30 insertions, 0 deletions
diff --git a/plugin/metrics/recorder.go b/plugin/metrics/recorder.go
new file mode 100644
index 000000000..a37f420d5
--- /dev/null
+++ b/plugin/metrics/recorder.go
@@ -0,0 +1,30 @@
+package metrics
+
+import (
+	"runtime"
+
+	"github.com/coredns/coredns/plugin/pkg/dnstest"
+
+	"github.com/miekg/dns"
+)
+
+// Recorder is a dnstest.Recorder specific to the metrics plugin.
+type Recorder struct {
+	*dnstest.Recorder
+	// CallerN holds the string return value of the call to runtime.Caller(N+1)
+	Caller [3]string
+}
+
+// NewRecorder makes and returns a new Recorder.
+func NewRecorder(w dns.ResponseWriter) *Recorder { return &Recorder{Recorder: dnstest.NewRecorder(w)} }
+
+// WriteMsg records the status code and calls the
+// underlying ResponseWriter's WriteMsg method.
+func (r *Recorder) WriteMsg(res *dns.Msg) error {
+	_, r.Caller[0], _, _ = runtime.Caller(1)
+	_, r.Caller[1], _, _ = runtime.Caller(2)
+	_, r.Caller[2], _, _ = runtime.Caller(3)
+	r.Len += res.Len()
+	r.Msg = res
+	return r.ResponseWriter.WriteMsg(res)
+}