package errs import ( "encoding/json" "fmt" "net/http" "github.com/pkg/errors" ) // StatusCoder interface is used by errors that returns the HTTP response code. type StatusCoder interface { StatusCode() int } // StackTracer must be by those errors that return an stack trace. type StackTracer interface { StackTrace() errors.StackTrace } // Option modifies the Error type. type Option func(e *Error) error // withDefaultMessage returns an Option that modifies the error by overwriting the // message only if it is empty. func withDefaultMessage(format string, args ...interface{}) Option { return func(e *Error) error { if len(e.Msg) > 0 { return e } e.Msg = fmt.Sprintf(format, args...) return e } } // WithMessage returns an Option that modifies the error by overwriting the // message only if it is empty. func WithMessage(format string, args ...interface{}) Option { return func(e *Error) error { e.Msg = fmt.Sprintf(format, args...) return e } } // WithKeyVal returns an Option that adds the given key-value pair to the // Error details. This is helpful for debugging errors. func WithKeyVal(key string, val interface{}) Option { return func(e *Error) error { if e.Details == nil { e.Details = make(map[string]interface{}) } e.Details[key] = val return e } } // Error represents the CA API errors. type Error struct { Status int Err error Msg string Details map[string]interface{} } // ErrorResponse represents an error in JSON format. type ErrorResponse struct { Status int `json:"status"` Message string `json:"message"` } // Cause implements the errors.Causer interface and returns the original error. func (e *Error) Cause() error { return e.Err } // Error implements the error interface and returns the error string. func (e *Error) Error() string { return e.Err.Error() } // StatusCode implements the StatusCoder interface and returns the HTTP response // code. func (e *Error) StatusCode() int { return e.Status } // Message returns a user friendly error, if one is set. func (e *Error) Message() string { if len(e.Msg) > 0 { return e.Msg } return e.Err.Error() } // Wrap returns an error annotating err with a stack trace at the point Wrap is // called, and the supplied message. If err is nil, Wrap returns nil. func Wrap(status int, e error, m string, args ...interface{}) error { if e == nil { return nil } _, opts := splitOptionArgs(args) if err, ok := e.(*Error); ok { err.Err = errors.Wrap(err.Err, m) e = err } else { e = errors.Wrap(e, m) } return StatusCodeError(status, e, opts...) } // Wrapf returns an error annotating err with a stack trace at the point Wrap is // called, and the supplied message. If err is nil, Wrap returns nil. func Wrapf(status int, e error, format string, args ...interface{}) error { if e == nil { return nil } as, opts := splitOptionArgs(args) if err, ok := e.(*Error); ok { err.Err = errors.Wrapf(err.Err, format, args...) e = err } else { e = errors.Wrapf(e, format, as...) } return StatusCodeError(status, e, opts...) } // MarshalJSON implements json.Marshaller interface for the Error struct. func (e *Error) MarshalJSON() ([]byte, error) { var msg string if len(e.Msg) > 0 { msg = e.Msg } else { msg = http.StatusText(e.Status) } return json.Marshal(&ErrorResponse{Status: e.Status, Message: msg}) } // UnmarshalJSON implements json.Unmarshaler interface for the Error struct. func (e *Error) UnmarshalJSON(data []byte) error { var er ErrorResponse if err := json.Unmarshal(data, &er); err != nil { return err } e.Status = er.Status e.Err = fmt.Errorf(er.Message) return nil } // Format implements the fmt.Formatter interface. func (e *Error) Format(f fmt.State, c rune) { if err, ok := e.Err.(fmt.Formatter); ok { err.Format(f, c) return } fmt.Fprint(f, e.Err.Error()) } // Messenger is a friendly message interface that errors can implement. type Messenger interface { Message() string } // StatusCodeError selects the proper error based on the status code. func StatusCodeError(code int, e error, opts ...Option) error { switch code { case http.StatusBadRequest: return BadRequestErr(e, opts...) case http.StatusUnauthorized: return UnauthorizedErr(e, opts...) case http.StatusForbidden: return ForbiddenErr(e, opts...) case http.StatusInternalServerError: return InternalServerErr(e, opts...) case http.StatusNotImplemented: return NotImplementedErr(e, opts...) default: return UnexpectedErr(code, e, opts...) } } var ( seeLogs = "Please see the certificate authority logs for more info." // BadRequestDefaultMsg 400 default msg BadRequestDefaultMsg = "The request could not be completed; malformed or missing data. " + seeLogs // UnauthorizedDefaultMsg 401 default msg UnauthorizedDefaultMsg = "The request lacked necessary authorization to be completed. " + seeLogs // ForbiddenDefaultMsg 403 default msg ForbiddenDefaultMsg = "The request was forbidden by the certificate authority. " + seeLogs // NotFoundDefaultMsg 404 default msg NotFoundDefaultMsg = "The requested resource could not be found. " + seeLogs // InternalServerErrorDefaultMsg 500 default msg InternalServerErrorDefaultMsg = "The certificate authority encountered an Internal Server Error. " + seeLogs // NotImplementedDefaultMsg 501 default msg NotImplementedDefaultMsg = "The requested method is not implemented by the certificate authority. " + seeLogs ) // splitOptionArgs splits the variadic length args into string formatting args // and Option(s) to apply to an Error. func splitOptionArgs(args []interface{}) ([]interface{}, []Option) { indexOptionStart := -1 for i, a := range args { if _, ok := a.(Option); ok { indexOptionStart = i break } } if indexOptionStart < 0 { return args, []Option{} } opts := []Option{} // Ignore any non-Option args that come after the first Option. for _, o := range args[indexOptionStart:] { if opt, ok := o.(Option); ok { opts = append(opts, opt) } } return args[:indexOptionStart], opts } // NewErr returns a new Error. If the given error implements the StatusCoder // interface we will ignore the given status. func NewErr(status int, err error, opts ...Option) error { var ( e *Error ok bool ) if e, ok = err.(*Error); !ok { if sc, ok := err.(StatusCoder); ok { e = &Error{Status: sc.StatusCode(), Err: err} } else { cause := errors.Cause(err) if sc, ok := cause.(StatusCoder); ok { e = &Error{Status: sc.StatusCode(), Err: err} } else { e = &Error{Status: status, Err: err} } } } for _, o := range opts { o(e) } return e } // Errorf creates a new error using the given format and status code. func Errorf(code int, format string, args ...interface{}) error { as, opts := splitOptionArgs(args) opts = append(opts, withDefaultMessage(NotImplementedDefaultMsg)) e := &Error{Status: code, Err: fmt.Errorf(format, as...)} for _, o := range opts { o(e) } return e } // InternalServer creates a 500 error with the given format and arguments. func InternalServer(format string, args ...interface{}) error { args = append(args, withDefaultMessage(InternalServerErrorDefaultMsg)) return Errorf(http.StatusInternalServerError, format, args...) } // InternalServerErr returns a 500 error with the given error. func InternalServerErr(err error, opts ...Option) error { opts = append(opts, withDefaultMessage(InternalServerErrorDefaultMsg)) return NewErr(http.StatusInternalServerError, err, opts...) } // NotImplemented creates a 501 error with the given format and arguments. func NotImplemented(format string, args ...interface{}) error { args = append(args, withDefaultMessage(NotImplementedDefaultMsg)) return Errorf(http.StatusNotImplemented, format, args...) } // NotImplementedErr returns a 501 error with the given error. func NotImplementedErr(err error, opts ...Option) error { opts = append(opts, withDefaultMessage(NotImplementedDefaultMsg)) return NewErr(http.StatusNotImplemented, err, opts...) } // BadRequest creates a 400 error with the given format and arguments. func BadRequest(format string, args ...interface{}) error { args = append(args, withDefaultMessage(BadRequestDefaultMsg)) return Errorf(http.StatusBadRequest, format, args...) } // BadRequestErr returns an 400 error with the given error. func BadRequestErr(err error, opts ...Option) error { opts = append(opts, withDefaultMessage(BadRequestDefaultMsg)) return NewErr(http.StatusBadRequest, err, opts...) } // Unauthorized creates a 401 error with the given format and arguments. func Unauthorized(format string, args ...interface{}) error { args = append(args, withDefaultMessage(UnauthorizedDefaultMsg)) return Errorf(http.StatusUnauthorized, format, args...) } // UnauthorizedErr returns an 401 error with the given error. func UnauthorizedErr(err error, opts ...Option) error { opts = append(opts, withDefaultMessage(UnauthorizedDefaultMsg)) return NewErr(http.StatusUnauthorized, err, opts...) } // Forbidden creates a 403 error with the given format and arguments. func Forbidden(format string, args ...interface{}) error { args = append(args, withDefaultMessage(ForbiddenDefaultMsg)) return Errorf(http.StatusForbidden, format, args...) } // ForbiddenErr returns an 403 error with the given error. func ForbiddenErr(err error, opts ...Option) error { opts = append(opts, withDefaultMessage(ForbiddenDefaultMsg)) return NewErr(http.StatusForbidden, err, opts...) } // NotFound creates a 404 error with the given format and arguments. func NotFound(format string, args ...interface{}) error { args = append(args, withDefaultMessage(NotFoundDefaultMsg)) return Errorf(http.StatusNotFound, format, args...) } // NotFoundErr returns an 404 error with the given error. func NotFoundErr(err error, opts ...Option) error { opts = append(opts, withDefaultMessage(NotFoundDefaultMsg)) return NewErr(http.StatusNotFound, err, opts...) } // UnexpectedErr will be used when the certificate authority makes an outgoing // request and receives an unhandled status code. func UnexpectedErr(code int, err error, opts ...Option) error { opts = append(opts, withDefaultMessage("The certificate authority received an "+ "unexpected HTTP status code - '%d'. "+seeLogs, code)) return NewErr(code, err, opts...) }