From dd3ce649adb3c25d6a0d776178760d5c67829209 Mon Sep 17 00:00:00 2001
From: Haowei Cai <haoweic@google.com>
Date: Mon, 28 Jan 2019 18:07:52 -0800
Subject: [PATCH] remove fallback logic for single-format endpoints

which were deprecated in 1.10
---
 .../client-go/discovery/discovery_client.go   |  2 +-
 .../controllers/openapi/aggregator_test.go    | 31 -------------------
 .../pkg/controllers/openapi/downloader.go     | 19 +-----------
 3 files changed, 2 insertions(+), 50 deletions(-)

diff --git a/staging/src/k8s.io/client-go/discovery/discovery_client.go b/staging/src/k8s.io/client-go/discovery/discovery_client.go
index ee74cfbce8c..627375aa047 100644
--- a/staging/src/k8s.io/client-go/discovery/discovery_client.go
+++ b/staging/src/k8s.io/client-go/discovery/discovery_client.go
@@ -392,7 +392,7 @@ func (d *DiscoveryClient) OpenAPISchema() (*openapi_v2.Document, error) {
 	if err != nil {
 		if errors.IsForbidden(err) || errors.IsNotFound(err) || errors.IsNotAcceptable(err) {
 			// single endpoint not found/registered in old server, try to fetch old endpoint
-			// TODO(roycaihw): remove this in 1.11
+			// TODO: remove this when kubectl/client-go don't work with 1.9 server
 			data, err = d.restClient.Get().AbsPath("/swagger-2.0.0.pb-v1").Do().Raw()
 			if err != nil {
 				return nil, err
diff --git a/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/aggregator_test.go b/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/aggregator_test.go
index 88b70eca0ee..96bd1fb8f5a 100644
--- a/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/aggregator_test.go
+++ b/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/aggregator_test.go
@@ -92,32 +92,6 @@ func (h handlerTest) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	w.Write(h.data)
 }
 
-type handlerDeprecatedTest struct {
-	etag string
-	data []byte
-}
-
-var _ http.Handler = handlerDeprecatedTest{}
-
-func (h handlerDeprecatedTest) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	// old server returns 403 on new endpoint
-	if r.URL.Path == "/openapi/v2" {
-		w.WriteHeader(http.StatusForbidden)
-		return
-	}
-	if len(h.etag) > 0 {
-		w.Header().Add("Etag", h.etag)
-	}
-	ifNoneMatches := r.Header["If-None-Match"]
-	for _, match := range ifNoneMatches {
-		if match == h.etag {
-			w.WriteHeader(http.StatusNotModified)
-			return
-		}
-	}
-	w.Write(h.data)
-}
-
 func assertDownloadedSpec(actualSpec *spec.Swagger, actualEtag string, err error,
 	expectedSpecID string, expectedEtag string) error {
 	if err != nil {
@@ -157,9 +131,4 @@ func TestDownloadOpenAPISpec(t *testing.T) {
 	actualSpec, actualEtag, _, err = s.Download(
 		handlerTest{data: []byte("{\"id\": \"test\"}"), etag: "etag_test1"}, "etag_test2")
 	assert.NoError(t, assertDownloadedSpec(actualSpec, actualEtag, err, "test", "etag_test1"))
-
-	// Test old server fallback path
-	actualSpec, actualEtag, _, err = s.Download(handlerDeprecatedTest{data: []byte("{\"id\": \"test\"}")}, "")
-	assert.NoError(t, assertDownloadedSpec(actualSpec, actualEtag, err, "test", "\"6E8F849B434D4B98A569B9D7718876E9-356ECAB19D7FBE1336BABB1E70F8F3025050DE218BE78256BE81620681CFC9A268508E542B8B55974E17B2184BBFC8FFFAA577E51BE195D32B3CA2547818ABE4\""))
-
 }
diff --git a/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/downloader.go b/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/downloader.go
index ea25e10ff1f..f5ffc0b7bd5 100644
--- a/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/downloader.go
+++ b/staging/src/k8s.io/kube-aggregator/pkg/controllers/openapi/downloader.go
@@ -89,7 +89,7 @@ func etagFor(data []byte) string {
 	return fmt.Sprintf("%s%X\"", locallyGeneratedEtagPrefix, sha512.Sum512(data))
 }
 
-// Download downloads openAPI spec from /openapi/v2 or /swagger.json endpoint of the given handler.
+// Download downloads openAPI spec from /openapi/v2 endpoint of the given handler.
 // httpStatus is only valid if err == nil
 func (s *Downloader) Download(handler http.Handler, etag string) (returnSpec *spec.Swagger, newEtag string, httpStatus int, err error) {
 	handler = s.handlerWithUser(handler, &user.DefaultInfo{Name: aggregatorUser})
@@ -109,23 +109,6 @@ func (s *Downloader) Download(handler http.Handler, etag string) (returnSpec *sp
 	writer := newInMemoryResponseWriter()
 	handler.ServeHTTP(writer, req)
 
-	// single endpoint not found/registered in old server, try to fetch old endpoint
-	// TODO(roycaihw): remove this in 1.11
-	if writer.respCode == http.StatusForbidden || writer.respCode == http.StatusNotFound {
-		req, err = http.NewRequest("GET", "/swagger.json", nil)
-		if err != nil {
-			return nil, "", 0, err
-		}
-
-		// Only pass eTag if it is not generated locally
-		if len(etag) > 0 && !strings.HasPrefix(etag, locallyGeneratedEtagPrefix) {
-			req.Header.Add("If-None-Match", etag)
-		}
-
-		writer = newInMemoryResponseWriter()
-		handler.ServeHTTP(writer, req)
-	}
-
 	switch writer.respCode {
 	case http.StatusNotModified:
 		if len(etag) == 0 {