# `letsencrypt.reverter`

Reverter class saves configuration checkpoints and allows for recovery.

class `letsencrypt.reverter.``Reverter`(config)

  Bases: `object`

  Reverter Class - save and revert configuration checkpoints.

  Note

  Consider moving everything over to CSV format.

  Parameters: | config (`letsencrypt.interfaces.IConfig`) – Configuration.

  `revert_temporary_config`()

    Reload users original configuration files after a temporary save.

    This function should reinstall the users original configuration files for all saves with temporary=True

    Raises: | .ReverterError – when unable to revert config

  `rollback_checkpoints`(rollback=1)

    Revert ‘rollback’ number of configuration checkpoints.

    Parameters: | rollback (int) – Number of checkpoints to reverse. A str num will be cast to an integer. So “2” is also acceptable.
    Raises: | .ReverterError – if there is a problem with the input or if the function is unable to correctly revert the configuration checkpoints

  `view_config_changes`(for_logging=False)

    Displays all saved checkpoints.

    All checkpoints are printed by `letsencrypt.interfaces.IDisplay.notification()`.

    Todo

    Decide on a policy for error handling, OSError IOError...

    Raises: | .errors.ReverterError – If invalid directory structure.

  `add_to_temp_checkpoint`(save_files, save_notes)

    Add files to temporary checkpoint.

    Parameters:

    - save_files (set) – set of filepaths to save
    - save_notes (str) – notes about changes during the save

  `add_to_checkpoint`(save_files, save_notes)

    Add files to a permanent checkpoint.

    Parameters:

    - save_files (set) – set of filepaths to save
    - save_notes (str) – notes about changes during the save

  `_add_to_checkpoint_dir`(cp_dir, save_files, save_notes)

    Add save files to checkpoint directory.

    Parameters:

    - cp_dir (str) – Checkpoint directory filepath
    - save_files (set) – set of files to save
    - save_notes (str) – notes about changes made during the save

    Raises:

    - IOError – if unable to open cp_dir + FILEPATHS file
    - .ReverterError – if unable to add checkpoint

  `_read_and_append`(filepath)

    Reads the file lines and returns a file obj.

    Read the file returning the lines, and a pointer to the end of the file.

  `_recover_checkpoint`(cp_dir)

    Recover a specific checkpoint.

    Recover a specific checkpoint provided by cp_dir Note: this function does not reload augeas.

    Parameters: | cp_dir (str) – checkpoint directory file path
    Raises: | errors.ReverterError – If unable to recover checkpoint

  `_run_undo_commands`(filepath)

    Run all commands in a file.

  `_check_tempfile_saves`(save_files)

    Verify save isn’t overwriting any temporary files.

    Parameters: | save_files (set) – Set of files about to be saved.
    Raises: | letsencrypt.errors.ReverterError – when save is attempting to overwrite a temporary file.

  `register_file_creation`(temporary, *files)

    Register the creation of all files during letsencrypt execution.

    Call this method before writing to the file to make sure that the file will be cleaned up if the program exits unexpectedly. (Before a save occurs)

    Parameters:

    - temporary (bool) – If the file creation registry is for a temp or permanent save.
    - *files – file paths (str) to be registered

    Raises: | letsencrypt.errors.ReverterError – If call does not contain necessary parameters or if the file creation is unable to be registered.

  `register_undo_command`(temporary, command)

    Register a command to be run to undo actions taken.

    Warning

    This function does not enforce order of operations in terms of file modification vs. command registration. All undo commands are run first before all normal files are reverted to their previous state. If you need to maintain strict order, you may create checkpoints before and after the the command registration. This function may be improved in the future based on demand.

    Parameters:

    - temporary (bool) – Whether the command should be saved in the IN_PROGRESS or TEMPORARY checkpoints.
    - command (list of str) – Command to be run.

  `_get_cp_dir`(temporary)

    Return the proper reverter directory.

  `recovery_routine`()

    Revert configuration to most recent finalized checkpoint.

    Remove all changes (temporary and permanent) that have not been finalized. This is useful to protect against crashes and other execution interruptions.

    Raises: | .errors.ReverterError – If unable to recover the configuration

  `_remove_contained_files`(file_list)

    Erase all files contained within file_list.

    Parameters: | file_list (str) – file containing list of file paths to be deleted
    Returns: | Success
    Return type: | bool
    Raises: | letsencrypt.errors.ReverterError – If all files within file_list cannot be removed

  `finalize_checkpoint`(title)

    Finalize the checkpoint.

    Timestamps and permanently saves all changes made through the use of `add_to_checkpoint()` and `register_file_creation()`

    Parameters: | title (str) – Title describing checkpoint
    Raises: | letsencrypt.errors.ReverterError – when the checkpoint is not able to be finalized.

  `_timestamp_progress_dir`()

    Timestamp the checkpoint.