Add IsRetryableError function

errors/error.go

@@ -2,6 +2,7 @@ package errors
 
 import (
 	"fmt"
+	"net/http"
 	"path"
 	"strconv"
 	"strings"
@@ -242,3 +243,20 @@ func pkgDescription(level int, err error) *Description {
 	} // if has stack
 	return desc
 }
+
+func IsRetryableError(err error) bool {
+
+	code := HTTPCode(err)
+
+	// 429 should always retry
+	if code == http.StatusTooManyRequests {
+		return true
+	}
+
+	// Retry for all except 200s and 400s
+	if code < 200 || (code >= 300 && code < 400) || code > 500 {
+		return true
+	}
+
+	return false
+}

errors/errors.go

@@ -2,7 +2,6 @@ package errors
 
 import (
 	"fmt"
-
 	pkg_errors "github.com/pkg/errors"
 )