Add a proper content type to Healthhook (#51)

Some application require the Content-Type be set to json
to parse json. So now we provide it by default

Author: geobeau

internal/controller/applicationdisruptionbudget_controller.go

@@ -222,6 +222,7 @@ func (r *ApplicationDisruptionBudgetResolver) CallHealthHook(ctx context.Context
 	}
 
 	client := &http.Client{}
+	headers := make(map[string][]string, 1)
 
 	data, err := json.Marshal(nd)
 	if err != nil {
@@ -233,6 +234,10 @@ func (r *ApplicationDisruptionBudgetResolver) CallHealthHook(ctx context.Context
 		return err
 	}
 
+	headers["Content-Type"] = []string{"application/json"}
+
+	req.Header = headers
+
 	resp, err := client.Do(req)
 	if err != nil {
 		return err

internal/controller/nodedisruption_controller_test.go

@@ -248,6 +248,8 @@ var _ = Describe("NodeDisruption controller", func() {
 						Expect(err).Should(Succeed())
 						hookURL = req.URL.String()
 						hookCallCount++
+						// Validate that the hook is called with valid headers
+						Expect(req.Header["Content-Type"][0]).Should(Equal("application/json"))
 						w.WriteHeader(http.StatusOK)
 					}