pkg/retry: retry 50{2,3,4} server errors

For quay.io it is quite common that if fails with 50{2,3,4} errors and
trying again is often enough to fix them. As such it would be good if
we retry them by default.

Fixes #2299

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

Author: Luap99

pkg/retry/retry.go

@@ -5,10 +5,12 @@ import (
 	"io"
 	"math"
 	"net"
+	"net/http"
 	"net/url"
 	"syscall"
 	"time"
 
+	"github.com/containers/image/v5/docker"
 	"github.com/docker/distribution/registry/api/errcode"
 	errcodev2 "github.com/docker/distribution/registry/api/v2"
 	"github.com/hashicorp/go-multierror"
@@ -81,6 +83,13 @@ func IsErrorRetryable(err error) bool {
 			return false
 		}
 		return true
+	case docker.UnexpectedHTTPStatusError:
+		// Retry on 502, 502 and 503 http server errors, they appear to be quite common in the field.
+		// https://github.com/containers/common/issues/2299
+		if e.StatusCode >= http.StatusBadGateway && e.StatusCode <= http.StatusGatewayTimeout {
+			return true
+		}
+		return false
 	case *net.OpError:
 		return IsErrorRetryable(e.Err)
 	case *url.Error: // This includes errors returned by the net/http client.