mw/health: add reload test (#980)

Start CoreDNS instance in call Restart() on it.

test/health_reload_test.go

@@ -0,0 +1,49 @@
+package test
+
+import (
+	"io/ioutil"
+	"log"
+	"net/http"
+	"testing"
+)
+
+func TestHealthReload(t *testing.T) {
+	log.SetOutput(ioutil.Discard)
+
+	// Corefile with for example without proxy section.
+	corefile := `example.org:0 {
+	health localhost:35080
+}
+`
+	i, err := CoreDNSServer(corefile)
+	if err != nil {
+		t.Fatalf("Could not get CoreDNS serving instance: %s", err)
+	}
+
+	resp, err := http.Get("http://localhost:35080/health")
+	if err != nil {
+		t.Fatalf("Could not get health: %s", err)
+	}
+	body, err := ioutil.ReadAll(resp.Body)
+	if x := string(body); x != "OK" {
+		t.Fatalf("Expect OK, got %s", x)
+	}
+	resp.Body.Close()
+
+	i, err = i.Restart(NewInput(corefile))
+	if err != nil {
+		t.Fatalf("Could not restart CoreDNS serving instance: %s", err)
+	}
+
+	defer i.Stop()
+
+	resp, err = http.Get("http://localhost:35080/health")
+	if err != nil {
+		t.Fatalf("Could not get health: %s", err)
+	}
+	body, err = ioutil.ReadAll(resp.Body)
+	if x := string(body); x != "OK" {
+		t.Fatalf("Expect OK, got %s", x)
+	}
+	resp.Body.Close()
+}