Add util to set transport defaults

pkg/util/http.go

@@ -18,6 +18,7 @@ package util
 
 import (
 	"io"
+	"net/http"
 	"net/url"
 	"strings"
 )
@@ -44,3 +45,20 @@ func IsProbableEOF(err error) bool {
 	}
 	return false
 }
+
+var defaultTransport = http.DefaultTransport.(*http.Transport)
+
+// SetTransportDefaults applies the defaults from http.DefaultTransport
+// for the Proxy, Dial, and TLSHandshakeTimeout fields if unset
+func SetTransportDefaults(t *http.Transport) *http.Transport {
+	if t.Proxy == nil {
+		t.Proxy = defaultTransport.Proxy
+	}
+	if t.Dial == nil {
+		t.Dial = defaultTransport.Dial
+	}
+	if t.TLSHandshakeTimeout == 0 {
+		t.TLSHandshakeTimeout = defaultTransport.TLSHandshakeTimeout
+	}
+	return t
+}