certbot.reverter

Reverter class saves configuration checkpoints and allows for recovery.

class certbot.reverter.Reverter(config)[source]

Bases: object

Reverter Class - save and revert configuration checkpoints.

This class can be used by the plugins, especially Installers, to undo changes made to the user’s system. Modifications to files and commands to do undo actions taken by the plugin should be registered with this class before the action is taken.

Once a change has been registered with this class, there are three states the change can be in. First, the change can be a temporary change. This should be used for changes that will soon be reverted, such as config changes for the purpose of solving a challenge. Changes are added to this state through calls to add_to_temp_checkpoint() and reverted when revert_temporary_config() or recovery_routine() is called.

The second state a change can be in is in progress. These changes are not temporary, however, they also have not been finalized in a checkpoint. A change must become in progress before it can be finalized. Changes are added to this state through calls to add_to_checkpoint() and reverted when recovery_routine() is called.

The last state a change can be in is finalized in a checkpoint. A change is put into this state by first becoming an in progress change and then calling finalize_checkpoint(). Changes in this state can be reverted through calls to rollback_checkpoints().

As a final note, creating new files and registering undo commands are handled specially and use the methods register_file_creation() and register_undo_command() respectively. Both of these methods can be used to create either temporary or in progress changes.

Note

Consider moving everything over to CSV format.

Parameters:config (certbot.interfaces.IConfig) – Configuration.
revert_temporary_config()[source]

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)[source]

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, num=None)[source]

Displays all saved checkpoints.

All checkpoints are printed by certbot.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)[source]

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)[source]

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)[source]

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)[source]

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)[source]

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)[source]

Run all commands in a file.

_check_tempfile_saves(save_files)[source]

Verify save isn’t overwriting any temporary files.

Parameters:save_files (set) – Set of files about to be saved.
Raises:certbot.errors.ReverterError – when save is attempting to overwrite a temporary file.
register_file_creation(temporary, *files)[source]

Register the creation of all files during certbot 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:

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

register_undo_command(temporary, command)[source]

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)[source]

Return the proper reverter directory.

recovery_routine()[source]

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)[source]

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:certbot.errors.ReverterError – If all files within file_list cannot be removed
finalize_checkpoint(title)[source]

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:certbot.errors.ReverterError – when the checkpoint is not able to be finalized.
_checkpoint_timestamp()[source]

Determine the timestamp of the checkpoint, enforcing monotonicity.

_timestamp_progress_dir()[source]

Timestamp the checkpoint.