Implement determineHTTPTransportProxyParsingFunc

client/pkg/transport/transport.go

@@ -26,24 +26,29 @@ import (
 
 type unixTransport struct{ *http.Transport }
 
+var httpTransportProxyParsingFunc = determineHTTPTransportProxyParsingFunc()
+
+func determineHTTPTransportProxyParsingFunc() func(req *http.Request) (*url.URL, error) {
+	// according to the comment of http.ProxyFromEnvironment: if the proxy URL is "localhost"
+	// (with or without a port number), then a nil URL and nil error will be returned.
+	// Thus, we workaround this limitation by manually setting an ENV named E2E_TEST_FORWARD_PROXY_IP
+	// and parse the URL (which is a localhost in our case)
+	if forwardProxy, exists := os.LookupEnv("E2E_TEST_FORWARD_PROXY_IP"); exists {
+		return func(req *http.Request) (*url.URL, error) {
+			return url.Parse(forwardProxy)
+		}
+	}
+	return http.ProxyFromEnvironment
+}
+
 func NewTransport(info TLSInfo, dialtimeoutd time.Duration) (*http.Transport, error) {
 	cfg, err := info.ClientConfig()
 	if err != nil {
 		return nil, err
 	}
 
 	t := &http.Transport{
-		Proxy: func(req *http.Request) (*url.URL, error) {
-			// according to the comment of http.ProxyFromEnvironment: if the
-			// proxy URL is "localhost" (with or without a port number),
-			// then a nil URL and nil error will be returned.
-			// Thus, we need to workaround this by manually setting an
-			// ENV named FORWARD_PROXY and parse the URL (which is a localhost in our case)
-			if forwardProxy, exists := os.LookupEnv("FORWARD_PROXY"); exists {
-				return url.Parse(forwardProxy)
-			}
-			return http.ProxyFromEnvironment(req)
-		},
+		Proxy: httpTransportProxyParsingFunc,
 		DialContext: (&net.Dialer{
 			Timeout: dialtimeoutd,
 			// value taken from http.DefaultTransport
@@ -63,7 +68,7 @@ func NewTransport(info TLSInfo, dialtimeoutd time.Duration) (*http.Transport, er
 		return dialer.DialContext(ctx, "unix", addr)
 	}
 	tu := &http.Transport{
-		Proxy:               http.ProxyFromEnvironment,
+		Proxy:               httpTransportProxyParsingFunc,
 		DialContext:         dialContext,
 		TLSHandshakeTimeout: 10 * time.Second,
 		TLSClientConfig:     cfg,

tests/framework/e2e/cluster.go

@@ -525,7 +525,7 @@ func (cfg *EtcdProcessClusterConfig) EtcdServerProcessConfig(tb testing.TB, i in
 		if cfg.EnvVars == nil {
 			cfg.EnvVars = make(map[string]string)
 		}
-		cfg.EnvVars["FORWARD_PROXY"] = fmt.Sprintf("http://127.0.0.1:%d", forwardProxyPort)
+		cfg.EnvVars["E2E_TEST_FORWARD_PROXY_IP"] = fmt.Sprintf("http://127.0.0.1:%d", forwardProxyPort)
 	}
 
 	name := fmt.Sprintf("%s-test-%d", testNameCleanRegex.ReplaceAllString(tb.Name(), ""), i)