Replace gRPC errors in business logic with internal ones (#558)

management/server/status/error.go

@@ -0,0 +1,72 @@
+package status
+
+import (
+	"fmt"
+)
+
+const (
+	// UserAlreadyExists indicates that user already exists
+	UserAlreadyExists Type = 1
+
+	// PreconditionFailed indicates that some pre-condition for the operation hasn't been fulfilled
+	PreconditionFailed Type = 2
+
+	// PermissionDenied indicates that user has no permissions to view data
+	PermissionDenied Type = 3
+
+	// NotFound indicates that the object wasn't found in the system (or under a given Account)
+	NotFound Type = 4
+
+	// Internal indicates some generic internal error
+	Internal Type = 5
+
+	// InvalidArgument indicates some generic invalid argument error
+	InvalidArgument Type = 6
+
+	// AlreadyExists indicates a generic error when an object already exists in the system
+	AlreadyExists Type = 7
+
+	// Unauthorized indicates that user is not authorized
+	Unauthorized Type = 8
+
+	// BadRequest indicates that user is not authorized
+	BadRequest Type = 9
+)
+
+// Type is a type of the Error
+type Type int32
+
+// Error is an internal error
+type Error struct {
+	ErrorType Type
+	Message   string
+}
+
+// Type returns the Type of the error
+func (e *Error) Type() Type {
+	return e.ErrorType
+}
+
+// Error is an error string
+func (e *Error) Error() string {
+	return e.Message
+}
+
+// Errorf returns Error(ErrorType, fmt.Sprintf(format, a...)).
+func Errorf(errorType Type, format string, a ...interface{}) error {
+	return &Error{
+		ErrorType: errorType,
+		Message:   fmt.Sprintf(format, a...),
+	}
+}
+
+// FromError returns Error, true if the provided error is of type of Error. nil, false otherwise
+func FromError(err error) (s *Error, ok bool) {
+	if err == nil {
+		return nil, true
+	}
+	if e, ok := err.(*Error); ok {
+		return e, true
+	}
+	return nil, false
+}