fix: use cloned http.DefaultTransport. issue-1857

Signed-off-by: Karthik Kondapally <[email protected]>

Author: karthikkondapally

api/client.go

@@ -27,14 +27,26 @@ import (
 )
 
 // DefaultRoundTripper is used if no RoundTripper is set in Config.
-var DefaultRoundTripper http.RoundTripper = &http.Transport{
-	Proxy: http.ProxyFromEnvironment,
-	DialContext: (&net.Dialer{
-		Timeout:   30 * time.Second,
-		KeepAlive: 30 * time.Second,
-	}).DialContext,
-	TLSHandshakeTimeout: 10 * time.Second,
-}
+var DefaultRoundTripper http.RoundTripper = func() http.RoundTripper {
+	if t, ok := http.DefaultTransport.(*http.Transport); ok {
+		return t.Clone()
+	}
+
+	//If unable to clone construct and return
+	//refer https://github.com/golang/go/blob/master/src/net/http/transport.go#L46
+	return &http.Transport{
+		Proxy: http.ProxyFromEnvironment,
+		DialContext: (&net.Dialer{
+			Timeout:   30 * time.Second,
+			KeepAlive: 30 * time.Second,
+		}).DialContext,
+		ForceAttemptHTTP2:     true,
+		MaxIdleConns:          100,
+		IdleConnTimeout:       90 * time.Second,
+		TLSHandshakeTimeout:   10 * time.Second,
+		ExpectContinueTimeout: 1 * time.Second,
+	}
+}()
 
 // Config defines configuration parameters for a new client.
 type Config struct {