Add tests for reverseproxy.

pkg/reverseproxy/handler_test.go

@@ -0,0 +1,94 @@
+package reverseproxy
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"testing"
+)
+
+type dummyResponseWriter struct {
+	buf    bytes.Buffer
+	code   int
+	header http.Header
+}
+
+func (w *dummyResponseWriter) Header() http.Header {
+	if w.header == nil {
+		w.header = http.Header{}
+	}
+	return w.header
+}
+func (w *dummyResponseWriter) WriteHeader(statusCode int)  { w.code = statusCode }
+func (w *dummyResponseWriter) Write(b []byte) (int, error) { return w.buf.Write(b) }
+
+func dummyRequest(t *testing.T) *http.Request {
+	t.Helper()
+	req, err := http.NewRequest("GET", "https://httpbin.org/anything", nil)
+	req.Header.Set("User-Agent", "dummy")
+	if err != nil {
+		t.Fatal(err)
+	}
+	return req
+}
+
+func dummyURL(t *testing.T) *url.URL {
+	url, err := url.Parse("https://httpbin.org")
+	if err != nil {
+		t.Fatal(err)
+	}
+	return url
+}
+
+func TestKubernetesLivenessProbe(t *testing.T) {
+	handler := NewHTTPHandler(dummyURL(t), &httputil.ReverseProxy{}, nil)
+	handler.IsProbeRequest = IsKubernetesProbeRequest
+
+	req := dummyRequest(t)
+	req.Header.Set("User-Agent", "kube-probe/1.26")
+
+	w := &dummyResponseWriter{}
+	handler.ServeHTTP(w, req)
+
+	if w.buf.String() != ProbeResponse {
+		t.Fatalf("expected response %s, actual %s", ProbeResponse, w.buf.String())
+	}
+	if w.code != ProbeStatusCode {
+		t.Fatalf("expected status code %d, actual %d", ProbeStatusCode, w.code)
+	}
+}
+
+type dummyHeaderInjector struct{}
+
+func (i *dummyHeaderInjector) GetHeaderName() string { return "dummy" }
+func (i *dummyHeaderInjector) GetHeaderValue(req *http.Request) (string, error) {
+	return "dummy-value", nil
+}
+
+func TestInjectHeader(t *testing.T) {
+	hj := &dummyHeaderInjector{}
+	handler := NewHTTPHandler(dummyURL(t), &httputil.ReverseProxy{}, []HeaderInjector{hj})
+	handler.IsProbeRequest = IsKubernetesProbeRequest
+
+	w := &dummyResponseWriter{}
+	handler.ServeHTTP(w, dummyRequest(t))
+
+	j := struct {
+		Headers struct {
+			Dummy string
+		}
+	}{}
+
+	t.Log(w.buf.String())
+
+	err := json.Unmarshal(w.buf.Bytes(), &j)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if j.Headers.Dummy != "dummy-value" {
+		t.Fatalf("expected header value %s, actual %s", "dummy-value", j.Headers.Dummy)
+	}
+}