Added handler and tests

Signed-off-by: Joe Elliott <[email protected]>

Author: joe-elliott

Diff for: cmd/query/app/additional_headers_handler.go

@@ -0,0 +1,30 @@
+// Copyright (c) 2020 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package app
+
+import (
+	"net/http"
+)
+
+func additionalHeadersHandler(h http.Handler, additionalHeaders http.Header) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		header := w.Header()
+		for key, values := range additionalHeaders {
+			header[key] = values
+		}
+
+		h.ServeHTTP(w, r)
+	})
+}

Diff for: cmd/query/app/additional_headers_test.go

@@ -0,0 +1,50 @@
+// Copyright (c) 2020 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package app
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAdditionalHeadersHandler(t *testing.T) {
+
+	additionalHeaders := http.Header{}
+	additionalHeaders.Add("Access-Control-Allow-Origin", "https://mozilla.org")
+	additionalHeaders.Add("Access-Control-Expose-Headers", "X-My-Custom-Header")
+	additionalHeaders.Add("Access-Control-Expose-Headers", "X-Another-Custom-Header")
+	additionalHeaders.Add("Access-Control-Request-Headers", "field1, field2")
+
+	emptyHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte{})
+	})
+
+	handler := additionalHeadersHandler(emptyHandler, additionalHeaders)
+	server := httptest.NewServer(handler)
+	defer server.Close()
+
+	req, err := http.NewRequest("GET", server.URL, nil)
+	assert.NoError(t, err)
+
+	resp, err := httpClient.Do(req)
+	assert.NoError(t, err)
+
+	for k, v := range additionalHeaders {
+		assert.Equal(t, v, resp.Header[k])
+	}
+}

Diff for: cmd/query/app/server.go

@@ -82,11 +82,11 @@ func createHTTPServer(querySvc *querysvc.QueryService, queryOpts *QueryOptions,
 	apiHandler.RegisterRoutes(r)
 	RegisterStaticHandler(r, logger, queryOpts)
 	var handler http.Handler = r
+	handler = additionalHeadersHandler(handler, queryOpts.AdditionalHeaders)
 	if queryOpts.BearerTokenPropagation {
-		handler = bearerTokenPropagationHandler(logger, r)
+		handler = bearerTokenPropagationHandler(logger, handler)
 	}
 	handler = handlers.CompressHandler(handler)
-	handler = additionalHeadersHandler(handler, queryOpts.AdditionalHeaders)
 	recoveryHandler := recoveryhandler.NewRecoveryHandler(logger, true)
 	return &http.Server{
 		Handler: recoveryHandler(handler),