package client import ( "encoding/json" "errors" "fmt" "io" "io/ioutil" "net/http" "github.com/docker/distribution/registry/api/errcode" ) // ErrNoErrorsInBody is returned when a HTTP response body parses to an empty // errcode.Errors slice. var ErrNoErrorsInBody = errors.New("no error details found in HTTP response body") // UnexpectedHTTPStatusError is returned when an unexpected HTTP status is // returned when making a registry api call. type UnexpectedHTTPStatusError struct { Status string } func (e *UnexpectedHTTPStatusError) Error() string { return fmt.Sprintf("received unexpected HTTP status: %s", e.Status) } // UnexpectedHTTPResponseError is returned when an expected HTTP status code // is returned, but the content was unexpected and failed to be parsed. type UnexpectedHTTPResponseError struct { ParseErr error StatusCode int Response []byte } func (e *UnexpectedHTTPResponseError) Error() string { return fmt.Sprintf("error parsing HTTP %d response body: %s: %q", e.StatusCode, e.ParseErr.Error(), string(e.Response)) } func parseHTTPErrorResponse(statusCode int, r io.Reader) error { var errors errcode.Errors body, err := ioutil.ReadAll(r) if err != nil { return err } // For backward compatibility, handle irregularly formatted // messages that contain a "details" field. var detailsErr struct { Details string `json:"details"` } err = json.Unmarshal(body, &detailsErr) if err == nil && detailsErr.Details != "" { switch statusCode { case http.StatusUnauthorized: return errcode.ErrorCodeUnauthorized.WithMessage(detailsErr.Details) case http.StatusTooManyRequests: return errcode.ErrorCodeTooManyRequests.WithMessage(detailsErr.Details) default: return errcode.ErrorCodeUnknown.WithMessage(detailsErr.Details) } } if err := json.Unmarshal(body, &errors); err != nil { return &UnexpectedHTTPResponseError{ ParseErr: err, StatusCode: statusCode, Response: body, } } if len(errors) == 0 { // If there was no error specified in the body, return // UnexpectedHTTPResponseError. return &UnexpectedHTTPResponseError{ ParseErr: ErrNoErrorsInBody, StatusCode: statusCode, Response: body, } } return errors } // HandleErrorResponse returns error parsed from HTTP response for an // unsuccessful HTTP response code (in the range 400 - 499 inclusive). An // UnexpectedHTTPStatusError returned for response code outside of expected // range. func HandleErrorResponse(resp *http.Response) error { if resp.StatusCode == 401 { err := parseHTTPErrorResponse(resp.StatusCode, resp.Body) if uErr, ok := err.(*UnexpectedHTTPResponseError); ok { return errcode.ErrorCodeUnauthorized.WithDetail(uErr.Response) } return err } if resp.StatusCode >= 400 && resp.StatusCode < 500 { return parseHTTPErrorResponse(resp.StatusCode, resp.Body) } return &UnexpectedHTTPStatusError{Status: resp.Status} } // SuccessStatus returns true if the argument is a successful HTTP response // code (in the range 200 - 399 inclusive). func SuccessStatus(status int) bool { return status >= 200 && status <= 399 }