util: add cephError as error type for all packages

Signed-off-by: Niels de Vos <[email protected]>

internal/errutil/error.go

@@ -0,0 +1,57 @@
+package errutil
+
+type cephErrno int
+
+// Error returns the error string for the errno.
+func (e cephErrno) Error() string {
+	_, strerror := FormatErrno(int(e))
+	return strerror
+}
+
+// cephError combines the source/component that generated the error and its
+// related errno.
+type cephError struct {
+	source string
+	errno  cephErrno
+}
+
+// Error returns the error string with the source and errno.
+func (e cephError) Error() string {
+	return FormatErrorCode(e.source, int(e.errno))
+}
+
+// Unwrap returns an error without the source.
+func (e cephError) Unwrap() error {
+	if e.errno == 0 {
+		return nil
+	}
+
+	return e.errno
+}
+
+// Is checks if both errors have the same errno.
+func (e cephError) Is(err error) bool {
+	ce, ok := err.(cephError)
+	if !ok {
+		return false
+	}
+
+	return e.errno == ce.errno
+}
+
+// ErrorCode returns the errno of the error.
+func (e cephError) ErrorCode() int {
+	return int(e.errno)
+}
+
+// GetError returns a new error that can be compared with errors.Is(),
+// independently of the source/component of the error.
+func GetError(source string, e int) error {
+	if e == 0 {
+		return nil
+	}
+	return cephError{
+		source: source,
+		errno:  cephErrno(int(e)),
+	}
+}