Datasources: Ensure the 'Host' custom header functions as expected (#80715)

Supports "Host" custom header.

Co-authored-by: Pei-Tang Huang <tangtheone@gmail.com>

pkg/services/datasources/service/datasource_test.go

@@ -865,6 +865,75 @@ func TestService_GetHttpTransport(t *testing.T) {
 		require.Equal(t, "Ok", bodyStr)
 	})
 
+	t.Run("Should set request Host if it is configured in custom headers within JsonData", func(t *testing.T) {
+		provider := httpclient.NewProvider()
+
+		sjson := simplejson.NewFromAny(map[string]any{
+			"httpHeaderName1": "Host",
+		})
+
+		sqlStore := db.InitTestDB(t)
+		secretsService := secretsmng.SetupTestService(t, fakes.NewFakeSecretsStore())
+		secretsStore := secretskvs.NewSQLSecretsKVStore(sqlStore, secretsService, log.New("test.logger"))
+		quotaService := quotatest.New(false, nil)
+		dsService, err := ProvideService(sqlStore, secretsService, secretsStore, cfg, featuremgmt.WithFeatures(), acmock.New(), acmock.NewMockedPermissionsService(), quotaService, &pluginstore.FakePluginStore{})
+		require.NoError(t, err)
+
+		ds := datasources.DataSource{
+			ID:       1,
+			OrgID:    1,
+			Name:     "kubernetes",
+			URL:      "http://k8s:8001",
+			Type:     "Kubernetes",
+			JsonData: sjson,
+		}
+
+		secureJsonData, err := json.Marshal(map[string]string{
+			"httpHeaderValue1": "example.com",
+		})
+		require.NoError(t, err)
+
+		err = secretsStore.Set(context.Background(), ds.OrgID, ds.Name, secretskvs.DataSourceSecretType, string(secureJsonData))
+		require.NoError(t, err)
+
+		headers := dsService.getCustomHeaders(sjson, map[string]string{"httpHeaderValue1": "example.com"})
+		require.Equal(t, "example.com", headers["Host"])
+
+		// 1. Start HTTP test server which checks the request headers
+		backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if r.Host == "example.com" {
+				w.WriteHeader(200)
+				_, err := w.Write([]byte("Ok"))
+				require.NoError(t, err)
+				return
+			}
+
+			w.WriteHeader(503)
+			_, err := w.Write([]byte("Server name mismatch"))
+			require.NoError(t, err)
+		}))
+		defer backend.Close()
+
+		// 2. Get HTTP transport from datasource which uses the test server as backend
+		ds.URL = backend.URL
+		rt, err := dsService.GetHTTPTransport(context.Background(), &ds, provider)
+		require.NoError(t, err)
+		require.NotNil(t, rt)
+
+		// 3. Send test request which should have the Authorization header set
+		req := httptest.NewRequest("GET", backend.URL+"/test-host", nil)
+		res, err := rt.RoundTrip(req)
+		require.NoError(t, err)
+		t.Cleanup(func() {
+			err := res.Body.Close()
+			require.NoError(t, err)
+		})
+		body, err := io.ReadAll(res.Body)
+		require.NoError(t, err)
+		bodyStr := string(body)
+		require.Equal(t, "Ok", bodyStr)
+	})
+
 	t.Run("Should use request timeout if configured in JsonData", func(t *testing.T) {
 		provider := httpclient.NewProvider()