Fix code with autopep8

If allowed by the remote server, try using sudo to remove
old backups (rm needs to be allowed in sudoers to run
without password)

PKGBUILD

@@ -0,0 +1,40 @@
+# PKGBUILD
+
+# Maintainer: Daniele Fucini <dfucini [at] gmail [dot] com>
+
+pkgname=simple_backup
+pkgdesc='Simple backup script that uses rsync to copy files'
+pkgver=4.1.6
+pkgrel=1
+url="https://git.shouldnt.work/fuxino/${pkgname}"
+arch=('any')
+license=('GPL-3.0-or-later')
+makedepends=('git'
+             'python-setuptools'
+             'python-build'
+             'python-installer'
+             'python-wheel')
+depends=('python>=3.10'
+         'rsync'
+         'python-dotenv')
+optdepends=('python-systemd: use systemd log'
+            'python-dbus: for desktop notifications'
+            'python-paramiko: for remote backup through ssh')
+conflicts=('simple_backup-git')
+source=(git+${url}?signed#tag=${pkgver})
+validpgpkeys=('7E12BC1FF3B6EDB2CD8053EB981A2B2A3BBF5514')
+sha256sums=('b3b29d9e2e1b7b949e95674d9a401e8eeb0d5f898e8450473dce94f799ee9df3')
+
+build()
+{
+    cd ${srcdir}/${pkgname}
+    python -m build --wheel --no-isolation
+}
+
+package()
+{
+    cd ${srcdir}/${pkgname}
+    python -m installer --destdir=${pkgdir} dist/*.whl
+    install -Dm644 ${pkgname}/${pkgname}.conf ${pkgdir}/usr/share/doc/${pkgname}/${pkgname}.conf
+    install -Dm644 man/${pkgname}.1 ${pkgdir}/usr/share/man/man1/${pkgname}.1
+}

README.md

@@ -49,3 +49,23 @@ For Arch Linux and Arch-based distros, two packages are available in the AUR (au
 - **simple_backup** for the release version
 - **simple_backup-git** for the git version
 
+## Remote backup
+> **Warning**
+> This feature is experimental
+
+It's possible to use a remote server as destination for the backup. Just use the --username (or -u) and --host arguments (or set them in the configuration file).
+For this to work, rsync must be installed on the server too.
+
+### Server authentication
+The best way to handle the authentication is to have an ssh agent running on your system, otherwise if a passphrase is necessary to unlock the ssh key, it will be necessary to enter it more than once.
+If needed, it's possible to specify the ssh key location with the --keyfile argument or in the configuration file.
+
+To be able to connect to the user's ssh agent when running simple_backup with sudo, make sure to preserve the SSH_AUTH_SOCK environment variable. For example:
+
+```bash
+sudo --preserve-env=SSH_AUTH_SOCK -s simple_backup [options]
+```
+
+or by editing the sudoers file.
+If SSH key authentication is not available, password authentication will be used instead.
+Check the man page for more details.

man/simple_backup.1

@@ -1,13 +1,13 @@
-.TH SIMPLE_BACKUP 1 2023-06-01 SIMPLE_BACKUP 3.2.6
+.TH SIMPLE_BACKUP 1 2025-03-30 SIMPLE_BACKUP 4.1.6
 .SH NAME
 simple_backup \- Backup files and folders using rsync
 .SH SYNOPSIS
-.BR simple_backup
+.B simple_backup
 \-h, \-\-help
 .PD 0
 .P
 .PD
-.BR simple_backup
+.B simple_backup
 [\-c, \-\-config FILE]
 [\-i, \-\-input INPUT [INPUT...]]
 [\-o, \-\-output DIR]
@@ -16,71 +16,177 @@ simple_backup \- Backup files and folders using rsync
 .PD
 .RS 14 [\-e, \-\-exclude FILE|DIR|PATTERN [FILE|...]]
 [\-k, \-\-keep N]
+[\-\-ssh\-host HOSTNAME]
+[\-\-ssh\-user USERNAME]
+[\-\-keyfile FILE]
+.PD 0
+.P
+.PD
 [\-s, \-\-checksum]
+[\-z, \-\-compress]
 [\-\-remove\-before\-backup]
 .RE
 .SH DESCRIPTION
-.BR simple_backup
+.B simple_backup
-is a python script for performing backup of files and folders. It uses rsync to copy the files to the specified location.
+is a python script for performing backup of files and folders.
-Parameters for the backup such as input files/directories, output location and files or folders to exclude can be specified
+.P
-in a configuration file (default location $HOME/.config/simple_backup/simple_backup.conf) or directly on the command line.
+It uses rsync to copy the files to the specified location. Parameters for the backup such as
+input files/directories, output location and files or folders to exclude can be specified
+in a configuration file (default location $HOME/.config/simple_backup/simple_backup.conf)
+or directly on the command line.
+.P
 Parameters specified on the command line will override those in the configuration file.
 .SH OPTIONS
 .TP
 .B \-h, \-\-help
-Print a short help message and exit
+Print a short help message and exit.
 .TP
 .B \-c, \-\-config FILE
 Specify the configuration file, useful to specify a different one from the default.
 .TP
 .B \-i, \-\-input INPUT [INPUT...]
-Specify the files and directories to backup. Multiple inputs can be specified, just separate them with a space.
+Specify the files and directories to backup. Multiple inputs can be specified, just separate
-If filenames or paths contain spaces, don't forget to escape them, or to use single or double quotes around them.
+them with a space. If filenames or paths contain spaces, don't forget to escape them,
+or to use single or double quotes around them.
 .TP
 .B \-o, \-\-output DIR
-Specify the directory where the files will be copied. The program will automatically create a subdirectory called
+Specify the directory where the files will be copied. The program will automatically
-\(aqsimple_backup\(aq (if it does not already exist) and inside this directory the actual backup directory (using
+create a subdirectory called \(aqsimple_backup\(aq (if it does not already exist) and
-the current date and time)
+inside this directory the actual backup directory (using the current date and time).
 .TP
 .B \-e, \-\-exclude FILE|DIR|PATTERN [FILE|...]]
-Specify files, directories or patterns to exclude from the backup. Matching files and directories will not be copied.
+Specify files, directories or patterns to exclude from the backup. Matching files and directories
-Multiple elements can be specified, in the same way as for the \-\-input option
+will not be copied. Multiple elements can be specified, in the same way as for the \-\-input option.
 .TP
 .B \-k, \-\-keep N
-Specify how many old backups (so excluding the current one) will be kept. The default behavior is to keep them all
+Specify how many old backups (so excluding the current one) will be kept. The default behavior
-(same as N=\-1)
+is to keep them all (same as N=\-1).
+.TP
+.B \-u, \-\-user USERNAME
+Explicitly specify the user running the backup (in case it is needed for home directory expansion).
+.TP
+.B \-\-ssh\-host HOSTNAME
+Hostname of the server where to copy the files in case of remote backup through SSH.
+.TP
+.B \-\-ssh\-user USERNAME
+Username for connecting to the server in case of remote backup.
+.TP
+.B \-\-keyfile FILE
+Location of the SSH key for server authentication. 
 .TP
 .B \-s, \-\-checksums
-Same as rsync option \(aq\-\-checksum\(aq, use checksums instead of mod\-time and size to skip files.
+Same as rsync option \(aq\-\-checksum\(aq, use checksums instead of mod\-time and size
+to skip files.
+.TP
+.B \-z, \-\-compress
+Compress data during transfer (rsync \(aq\-\-compress\(aq option). Useful for remote backup
+if saving bandwith is needed.
 .TP
 .B \-\-remove\-before\-backup
-Remove old backups (if necessary) before creating the new backup. Useful to free some space before performing the backup.
+Remove old backups (if necessary) before creating the new backup. Useful to free some space
+before performing the backup.
 Default behavior is to remove old backups after successfully completing the backup.
 .TP
 .B \-\-no\-syslog
-Don't use systemd journal for logging
+Don't use systemd journal for logging.
+.TP
+.B \-\-rsync\-options OPTIONS [OPTION...]
+By default, the following rsync options are used:
+.RS
+.P
+    \-a \-r \-v \-h \-s \-H \-X
+.P
+Using \-\-rsync\-options it is possible to manually select which options to use. Supported values are the following:
+.P
+    \-a, \-l, \-p, \-t, \-g, \-o, \-c, \-h, \-D, \-H, \-X, \-s
+.P
+Options \-r and \-v are used in any case. Not that options must be specified without dash (\-), for example:
+.P
+.EX
+    simple_backup \-\-rsync\-options a l p
+.EE
+.P
+Check
+.BR rsync (1)
+for details about the options.
+.RE
+.TP
+.B \-\-remote\-sudo
+Run rsync on the remote server with sudo. This is needed if you want to preserve the owner of the files/folders to be copied (rsync \-\-owner option). For this to work the user used to login to the server obviously need to be allowed to use sudo. In addition, the user need to be able to run rsync with sudo without a password. To do this, /etc/sudoers on the server need to be edited adding a line like this one:
+.RS
+.P
+    <username> ALL=NOPASSWD:<path/to/rsync>
+.P
+To be able to remove old backups generated with \-\-remote\-sudo (see \-\-keep option), also
+.BR rm (1)
+needs to be allowed to run without password in the same way.
+.RE
+.TP
+.B \-\-numeric\-ids
+Use rsync \-\-numeric\-ids option. This causes rsync to use numeric uid/gid instead of trying to map uid/gid names from the local machine to the server.
 .SH CONFIGURATION
-An example configuration file is provided at \(aq/etc/simple_backup/simple_backup.conf\(aq. Copy it to the default location
+An example configuration file is provided at \(aq/usr/share/doc/simple_backup/simple_backup.conf\(aq.
-($HOME/.config/simple_backup) and edit it as needed.
+Copy it to the default location ($HOME/.config/simple_backup) and edit it as needed.
+.SH REMOTE BACKUP
+It is possible to choose a directory on a remote server as destination for the backup. The files
+are copied by rsync through SSH. Server hostname and username must be specified, either in the
+configuration file, or on the command line (\(aq\-\-ssh\-host\(aq and \(aq\-\-ssh\-user\(aq options).
+.SS AUTHENTICATION
+For authentication, it is possible to use SSH key or password.
+.P
+When using SSH key, the best way to connect to the server is to have an SSH agent running.
+Otherwise, if the SSH key is encrypted, it will be necessary to enter the passphrase more
+than once. It is possible to specify the SSH key to use with the option \(aq\-\-keyfile\(aq,
+if necessary.
+.P
+When running
+.B simple_backup
+with
+.B sudo,
+in order to connect to the user\(aqs SSH agent it is necessary to preserve the \(aqSSH_AUTH_SOCK\(aq environment variable, for example:
+.P
+.EX
+    sudo --preserve-env=SSH_AUTH_SOCK -s simple_backup [options]
+.EE
+.P
+It is also possible to make this permanent by editing the
+.B sudoers
+file (see
+.BR sudoers (5))
+.P
+If SSH key authentication is not available, password authentication will be used instead.
+Note that in this case
+.B sshpass
+(if available) will be used to send the password to rsync, to avoid prompting the user for
+the password multiple
+times. This can pose some security risks, see
+.BR sshpass (1)
+for details. For this reason, use SSH key authentication if possible.
 .SH EXIT STATUS
 .TP
 .B 0
-The backup was completed without errors
+The backup was completed without errors.
 .TP
 .B 1
-No valid inputs selected for backup
+No valid inputs selected for backup.
 .TP
 .B 2
-Backup failed because output directory for storing the backup does not exist
+Backup failed because output directory for storing the backup does not exist.
 .TP
 .B 3
-Permission denied to access the output directory
+Permission denied to access the output directory.
 .TP
 .B 4
-rsync error (rsync returned a non-zero value)
+rsync error (rsync returned a non-zero value).
+.TP
+.B 5
+SSH connection failed.
+.TP
+.B 6
+Bad configuration file.
 .SH SEE ALSO
 .BR rsync (1)
 .SH AUTHORS
-.MT https://github.com/Fuxino
+.MT https://git.shouldnt.work/fuxino
 Daniele Fucini
 .ME

setup.cfg

@@ -6,23 +6,22 @@ long_description = file: README.md
 author = Daniele Fucini
 author_email = dfucini@gmail.com
 license = GPL3
-url = https://github.com/Fuxino/simple_backup
+url = https://git.shouldnt.work/fuxino
 classifiers =
-   Development Status :: 5 - Production/Stable
+   Development Status :: 4 - Beta
    Environment :: Console
    License :: OSI Approved :: GNU General Public License v3 (GPLv3)
    Natural Language :: English
    Operating System :: POSIX :: Linux
-   Programming Language :: Python :: 3.7
-   Programming Language :: Python :: 3.8
-   Programming Language :: Python :: 3.9
    Programming Language :: Python :: 3.10
    Programming Language :: Python :: 3.11
+   Programming Language :: Python :: 3.12
+   Programming Language :: Python :: 3.13
    Topic :: System :: Archiving :: Backup
 
 [options]
 packages = simple_backup
-python_requires = >=3.7
+python_requires = >=3.10
 install_requires =
    python-dotenv
 
@@ -31,6 +30,8 @@ JOURNAL =
     systemd-python
 NOTIFICATIONS =
     dbus-python
+REMOTE =
+    paramiko
 
 [options.entry_points]
 console_scripts =

simple_backup/__init__.py

@@ -1,3 +1,3 @@
 """Init."""
 
-__version__ = '3.4.1'
+__version__ = '4.1.6'

simple_backup/simple_backup.conf

@@ -1,8 +1,8 @@
 # Example config file for simple_backup
 
-[default]
+[backup]
 # Files and directories to backup. Multiple items can be separated using a comma (','). It is possible to use wildcards (i.e. '*' to match multiple characters and '~' for the user's home directory).
-inputs=/home/my_home,/etc
+inputs=/home/user
 
 # Output directory.
 backup_dir=/media/Backup
@@ -12,3 +12,11 @@ exclude=*.bak
 
 # Number of old backups (i.e. excluding the one that's being created) to keep (use -1 to keep all)
 keep=-1
+
+# Uncomment the following section to enable backup to remote server through ssh
+# [server]
+# ssh_host=
+# ssh_user=
+# ssh_keyfile=
+# remote_sudo=
+# numeric_ids=

simple_backup/simple_backup.py

@@ -1,10 +1,24 @@
-#!/usr/bin/python3
+#!/usr/bin/env python3
+
+"""
+A simple python script that calls rsync to perform a backup
+
+Parameters can be specified on the command line or using a configuration file
+Backup to a remote server is also supported (experimental)
+
+Classes:
+    MyFormatter
+    Backup
+"""
 
 # Import libraries
 import sys
 import os
+from typing import Callable, List, Optional, ParamSpec, TypeVar, Union
+import warnings
 from functools import wraps
-from shutil import rmtree
+from shutil import rmtree, which
+import shlex
 import argparse
 import configparser
 import logging
@@ -13,10 +27,19 @@ from timeit import default_timer
 from subprocess import Popen, PIPE, STDOUT
 from datetime import datetime
 from tempfile import mkstemp
+from getpass import GetPassWarning, getpass
 from glob import glob
 
 from dotenv import load_dotenv
 
+warnings.filterwarnings('error')
+
+try:
+    import paramiko
+    from paramiko import RSAKey, Ed25519Key, ECDSAKey, DSSKey
+except ImportError:
+    pass
+
 try:
     from systemd import journal
 except ImportError:
@@ -29,15 +52,6 @@ except ImportError:
 
 
 load_dotenv()
-euid = os.geteuid()
-
-if euid == 0:
-    user = os.getenv('SUDO_USER')
-    homedir = os.path.expanduser(f'~{user}')
-else:
-    user = os.getenv('USER')
-    homedir = os.getenv('HOME')
-
 logging.getLogger().setLevel(logging.DEBUG)
 logger = logging.getLogger(os.path.basename(__file__))
 c_handler = StreamHandler()
@@ -54,56 +68,131 @@ if journal:
     j_handler.setFormatter(j_format)
     logger.addHandler(j_handler)
 
+P = ParamSpec('P')
+R = TypeVar('R')
 
-def timing(_logger):
+
-    def decorator_timing(func):
+def timing(func: Callable[P, R]) -> Callable[P, R]:
+    """Decorator to measure execution time of a function
+
+        Parameters:
+            func: Function to decorate
+    """
     @wraps(func)
-        def wrapper_timing(*args, **kwargs):
+    def wrapper(*args: P.args, **kwargs: P.kwargs) -> R:
         start = default_timer()
 
         value = func(*args, **kwargs)
 
         end = default_timer()
 
-            _logger.info(f'Elapsed time: {end - start:.3f} seconds')
+        logger.info('Elapsed time: %.3f seconds', end - start)
 
         return value
 
-        return wrapper_timing
+    return wrapper
-
-    return decorator_timing
 
 
 class MyFormatter(argparse.RawTextHelpFormatter, argparse.ArgumentDefaultsHelpFormatter):
-    pass
+    """Custom format for argparse help text"""
 
 
 class Backup:
+    """Main class defining parameters and functions for performing backup
 
-    def __init__(self, inputs, output, exclude, keep, options, remove_before=False):
+    Attributes:
+        inputs: list
+            Files and folders that will be backup up
+        output: str
+            Path where the backup will be saved
+        exclude: list
+            List of files/folders/patterns to exclude from backup
+        options: str
+            String representing main backup options for rsync
+        keep: int
+            Number of old backup to preserve
+        ssh_host: str
+            Hostname of server (for remote backup)
+        ssh_user: str
+            Username for server login (for remote backup)
+        ssh_keyfile: str
+            Location of ssh key
+        remote_sudo: bool
+            Run remote rsync with sudo
+        remove_before: bool
+            Indicate if removing old backups will be performed before copying files
+
+    Methods:
+        check_params():
+            Check if parameters for the backup are valid
+        define_backup_dir():
+            Define the actual backup dir
+        remove_old_backups():
+            Remove old backups if there are more than indicated by 'keep'
+        find_last_backup():
+            Get path of last backup (from last_backup symlink) for rsync --link-dest
+        run():
+            Perform the backup
+    """
+
+    def __init__(self, inputs: List[str], output: str, exclude: List[str], keep: int, options: str,
+                 ssh_host: Optional[str] = None, ssh_user: Optional[str] = None, ssh_keyfile: Optional[str] = None,
+                 remote_sudo: bool = False, remove_before: bool = False, verbose: bool = False) -> None:
         self.inputs = inputs
         self.output = output
         self.exclude = exclude
         self.options = options
         self.keep = keep
-        self.remove_before = remove_before
+        self.ssh_host = ssh_host
+        self.ssh_user = ssh_user
+        self.ssh_keyfile = ssh_keyfile
+        self.remote_sudo = remote_sudo
+        self._remove_before = remove_before
+        self._verbose = verbose
         self._last_backup = ''
+        self._server = ''
         self._output_dir = ''
         self._inputs_path = ''
         self._exclude_path = ''
-        self._err_flag = False
+        self._remote = False
+        self._ssh = None
+        self._password_auth = False
+        self._password = None
+
+    def check_params(self, homedir: str = '') -> int:
+        """Check if parameters for the backup are valid"""
 
-    def check_params(self):
         if self.inputs is None or len(self.inputs) == 0:
-            logger.info('No existing files or directories specified for backup. Nothing to do')
+            logger.info(
+                'No existing files or directories specified for backup. Nothing to do')
 
             return 1
 
         if self.output is None:
-            logger.critical('No output path specified. Use -o argument or specify output path in configuration file')
+            logger.critical(
+                'No output path specified. Use -o argument or specify output path in configuration file')
 
             return 2
 
+        if self.ssh_host is not None and self.ssh_user is not None:
+            self._remote = True
+
+        if self._remote:
+            self._ssh = self._ssh_connect(homedir)
+
+            if self._ssh is None:
+                return 5
+
+            _, stdout, _ = self._ssh.exec_command(
+                f'if [ -d "{self.output}" ]; then echo "ok"; fi')
+
+            output = stdout.read().decode('utf-8').strip()
+
+            if output != 'ok':
+                logger.critical('Output path for backup does not exist')
+
+                return 2
+        else:
             if not os.path.isdir(self.output):
                 logger.critical('Output path for backup does not exist')
 
@@ -117,19 +206,63 @@ class Backup:
         return 0
 
     # Function to create the actual backup directory
-    def create_backup_dir(self):
+    def define_backup_dir(self) -> None:
+        """Define the actual backup dir"""
         now = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
         self._output_dir = f'{self.output}/simple_backup/{now}'
 
-        os.makedirs(self._output_dir, exist_ok=True)
+        if self._remote:
+            self._server = f'{self.ssh_user}@{self.ssh_host}:'
 
-    def remove_old_backups(self):
+    def remove_old_backups(self) -> None:
+        """Remove old backups if there are more than indicated by 'keep'"""
+
+        if self._remote:
+            assert self._ssh is not None
+
+            _, stdout, _ = self._ssh.exec_command(
+                f'ls {self.output}/simple_backup')
+
+            dirs = stdout.read().decode('utf-8').strip().split('\n')
+
+            n_backup = len(dirs)
+
+            if not self._remove_before:
+                n_backup -= 1
+
+            count = 0
+
+            if n_backup > self.keep:
+                logger.info('Removing old backups...')
+                dirs.sort()
+
+                for i in range(n_backup - self.keep):
+                    if self.remote_sudo:
+                        _, _, stderr = self._ssh.exec_command(
+                            f'sudo rm -r "{self.output}/simple_backup/{dirs[i]}"')
+                    else:
+                        _, _, stderr = self._ssh.exec_command(
+                            f'rm -r "{self.output}/simple_backup/{dirs[i]}"')
+
+                    err = stderr.read().decode('utf-8').strip().split('\n')[0]
+
+                    if err != '':
+                        logger.error(
+                            'Error while removing backup %s.', {dirs[i]})
+                        logger.error(err)
+                    else:
+                        count += 1
+        else:
             try:
                 dirs = os.listdir(f'{self.output}/simple_backup')
             except FileNotFoundError:
                 return
 
-        n_backup = len(dirs) - 1
+            n_backup = len(dirs)
+
+            if not self._remove_before:
+                n_backup -= 1
+
             count = 0
 
             if n_backup > self.keep:
@@ -141,27 +274,47 @@ class Backup:
                         rmtree(f'{self.output}/simple_backup/{dirs[i]}')
                         count += 1
                     except FileNotFoundError:
-                    logger.error(f'Error while removing backup {dirs[i]}. Directory not found')
+                        logger.error(
+                            'Error while removing backup %s. Directory not found', dirs[i])
                     except PermissionError:
-                    logger.error(f'Error while removing backup {dirs[i]}. Permission denied')
+                        logger.error(
+                            'Error while removing backup %s. Permission denied', dirs[i])
 
         if count == 1:
-                logger.info(f'Removed {count} backup')
+            logger.info('Removed %d backup', count)
-            else:
+        elif count > 1:
-                logger.info(f'Removed {count} backups')
+            logger.info('Removed %d backups', count)
 
-    def find_last_backup(self):
+    def find_last_backup(self) -> None:
+        """Get path of last backup (from last_backup symlink) for rsync --link-dest"""
+
+        if self._remote:
+            if self._ssh is None:
+                logger.critical('SSH connection to server failed')
+                sys.exit(5)
+
+            _, stdout, _ = self._ssh.exec_command(
+                f'find {self.output}/simple_backup/ -mindepth 1 -maxdepth 1 -type d | sort')
+            output = stdout.read().decode('utf-8').strip().split('\n')
+
+            if output[-1] != '':
+                self._last_backup = output[-1]
+            else:
+                logger.info('No previous backups available')
+        else:
             try:
-            dirs = sorted([f.path for f in os.scandir(f'{self.output}/simple_backup') if f.is_dir(follow_symlinks=False)])
+                dirs = sorted([f.path for f in os.scandir(
+                    f'{self.output}/simple_backup') if f.is_dir(follow_symlinks=False)])
             except FileNotFoundError:
                 logger.info('No previous backups available')
 
                 return
             except PermissionError:
-            logger.critical('Cannot access the backup directory. Permission denied')
+                logger.critical(
+                    'Cannot access the backup directory. Permission denied')
 
                 try:
-                notify('Backup failed (check log for details)')
+                    _notify('Backup failed (check log for details)')
                 except NameError:
                     pass
 
@@ -172,36 +325,197 @@ class Backup:
             except IndexError:
                 logger.info('No previous backups available')
 
+    def _ssh_connect(self, homedir: str = '') -> paramiko.client.SSHClient:
+        try:
+            ssh = paramiko.SSHClient()
+        except NameError:
+            logger.error('Install paramiko for ssh support')
+
+            return None
+
+        try:
+            ssh.load_host_keys(filename=f'{homedir}/.ssh/known_hosts')
+        except FileNotFoundError:
+            logger.warning('Cannot find file %s/.ssh/known_hosts', homedir)
+
+        ssh.set_missing_host_key_policy(paramiko.WarningPolicy())
+
+        try:
+            ssh.connect(self.ssh_host, username=self.ssh_user)
+
+            return ssh
+        except UserWarning:
+            k = input(
+                f'Unknown key for host {self.ssh_host}. Continue anyway? (Y/N) ')
+
+            if k[0].upper() == 'Y':
+                ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
+            else:
+                return None
+        except paramiko.BadHostKeyException as e:
+            logger.critical('Can\'t connect to the server.')
+            logger.critical(e)
+
+            return None
+        except paramiko.SSHException:
+            pass
+
+        try:
+            ssh.connect(self.ssh_host, username=self.ssh_user)
+
+            return ssh
+        except paramiko.SSHException:
+            pass
+
+        if self.ssh_keyfile is None:
+            try:
+                password = getpass(
+                    f'{self.ssh_user}@{self.ssh_host}\'s password: ')
+                ssh.connect(self.ssh_host, username=self.ssh_user,
+                            password=password)
+
+                self._password_auth = True
+                os.environ['SSHPASS'] = password
+
+                return ssh
+            except GetPassWarning as e:
+                logger.critical('Unable to get password')
+                logger.critical(e)
+
+                return None
+            except paramiko.SSHException as e:
+                logger.critical('Can\'t connect to the server.')
+                logger.critical(e)
+
+                return None
+
+        pkey = None
+
+        try:
+            pkey = RSAKey.from_private_key_file(self.ssh_keyfile)
+        except paramiko.PasswordRequiredException:
+            password = getpass(
+                f'Enter passwphrase for key \'{self.ssh_keyfile}\': ')
+
+            try:
+                pkey = RSAKey.from_private_key_file(self.ssh_keyfile, password)
+            except paramiko.SSHException:
+                pass
+
+        if pkey is None:
+            try:
+                pkey = Ed25519Key.from_private_key_file(self.ssh_keyfile)
+            except paramiko.PasswordRequiredException:
+                try:
+                    pkey = Ed25519Key.from_private_key_file(
+                        self.ssh_keyfile, password)
+                except paramiko.SSHException:
+                    pass
+
+        if pkey is None:
+            try:
+                pkey = ECDSAKey.from_private_key_file(self.ssh_keyfile)
+            except paramiko.PasswordRequiredException:
+                try:
+                    pkey = ECDSAKey.from_private_key_file(
+                        self.ssh_keyfile, password)
+                except paramiko.SSHException:
+                    pass
+
+        if pkey is None:
+            try:
+                pkey = DSSKey.from_private_key_file(self.ssh_keyfile)
+            except paramiko.PasswordRequiredException:
+                try:
+                    pkey = DSSKey.from_private_key_file(
+                        self.ssh_keyfile, password)
+                except paramiko.SSHException:
+                    pass
+
+        try:
+            ssh.connect(self.ssh_host, username=self.ssh_user, pkey=pkey)
+        except paramiko.SSHException:
+            logger.critical('SSH connection to server failed')
+
+            return None
+
+        return ssh
+
+    def _returncode_log(self, returncode: int) -> None:
+        match returncode:
+            case 2:
+                logger.error(
+                    'Rsync error (return code 2) - Protocol incompatibility')
+            case 3:
+                logger.error(
+                    'Rsync error (return code 3) - Errors selecting input/output files, dirs')
+            case 4:
+                logger.error(
+                    'Rsync error (return code 4) - Requested action not supported')
+            case 5:
+                logger.error(
+                    'Rsync error (return code 5) - Error starting client-server protocol')
+            case 10:
+                logger.error(
+                    'Rsync error (return code 10) - Error in socket I/O')
+            case 11:
+                logger.error(
+                    'Rsync error (return code 11) - Error in file I/O')
+            case 12:
+                logger.error(
+                    'Rsync error (return code 12) - Error in rsync protocol data stream')
+            case 22:
+                logger.error(
+                    'Rsync error (return code 22) - Error allocating core memory buffers')
+            case 23:
+                logger.warning(
+                    'Rsync error (return code 23) - Partial transfer due to error')
+            case 24:
+                logger.warning(
+                    'Rsync error (return code 24) - Partial transfer due to vanished source files')
+            case 30:
+                logger.error(
+                    'Rsync error (return code 30) - Timeout in data send/receive')
+            case 35:
+                logger.error(
+                    'Rsync error (return code 35) - Timeout waiting for daemon connection')
+            case _:
+                logger.error(
+                    'Rsync error (return code %d) - Check rsync(1) for details', returncode)
+
     # Function to read configuration file
-    @timing(logger)
+    @timing
-    def run(self):
+    def run(self) -> int:
+        """Perform the backup"""
+
         logger.info('Starting backup...')
 
         try:
-            notify('Starting backup...')
+            _notify('Starting backup...')
         except NameError:
             pass
 
+        self.define_backup_dir()
         self.find_last_backup()
-        self.create_backup_dir()
 
         _, self._inputs_path = mkstemp(prefix='tmp_inputs', text=True)
         count = 0
 
-        with open(self._inputs_path, 'w') as fp:
+        with open(self._inputs_path, 'w', encoding='utf-8') as fp:
             for i in self.inputs:
                 if not os.path.exists(i):
-                    logger.warning(f'Input {i} not found. Skipping')
+                    logger.warning('Input %s not found. Skipping', i)
                 else:
                     fp.write(i)
                     fp.write('\n')
                     count += 1
 
         if count == 0:
-            logger.info('No existing files or directories specified for backup. Nothing to do')
+            logger.info(
+                'No existing files or directories specified for backup. Nothing to do')
 
             try:
-                notify('Backup finished. No files copied')
+                _notify('Backup finished. No files copied')
             except NameError:
                 pass
 
@@ -209,174 +523,391 @@ class Backup:
 
         _, self._exclude_path = mkstemp(prefix='tmp_exclude', text=True)
 
-        with open(self._exclude_path, 'w') as fp:
+        with open(self._exclude_path, 'w', encoding='utf-8') as fp:
             if self.exclude is not None:
                 for e in self.exclude:
                     fp.write(e)
                     fp.write('\n')
 
-        if self.keep != -1 and self.remove_before:
+        if self.keep != -1 and self._remove_before:
             self.remove_old_backups()
 
         logger.info('Copying files. This may take a long time...')
 
         if self._last_backup == '':
-            rsync = f'rsync {self.options} --exclude-from={self._exclude_path} ' +\
+            rsync = f'/usr/bin/rsync {self.options} --exclude-from={self._exclude_path} ' +\
-                    f'--files-from={self._inputs_path} / "{self._output_dir}" ' +\
+                f'--files-from={self._inputs_path} / "{self._server}{self._output_dir}"'
-                    '--ignore-missing-args'
         else:
-            rsync = f'rsync {self.options} --link-dest="{self._last_backup}" --exclude-from=' +\
+            rsync = f'/usr/bin/rsync {self.options} --link-dest="{self._last_backup}" --exclude-from=' +\
-                    f'{self._exclude_path} --files-from={self._inputs_path} / "{self._output_dir}" ' +\
+                f'{self._exclude_path} --files-from={self._inputs_path} / "{self._server}{self._output_dir}"'
-                    '--ignore-missing-args'
 
-        p = Popen(rsync, stdout=PIPE, stderr=STDOUT, shell=True)
+        euid = os.geteuid()
+
+        if euid == 0 and self.ssh_keyfile is not None:
+            rsync = f'{rsync} -e \'ssh -i {self.ssh_keyfile} -o StrictHostKeyChecking=no\''
+        elif self._password_auth and which('sshpass'):
+            rsync = f'{rsync} -e \'sshpass -e ssh -l {self.ssh_user} -o StrictHostKeyChecking=no\''
+        else:
+            rsync = f'{rsync} -e \'ssh -o StrictHostKeyChecking=no\''
+
+        if self._remote and self.remote_sudo:
+            rsync = f'{rsync} --rsync-path="sudo rsync"'
+
+        args = shlex.split(rsync)
+
+        with Popen(args, stdin=PIPE, stdout=PIPE, stderr=STDOUT, shell=False) as p:
+            output: Union[bytes, List[str]]
             output, _ = p.communicate()
 
-        if p.returncode != 0:
+            try:
-            self._err_flag = True
+                del os.environ['SSHPASS']
+            except KeyError:
+                pass
+
+            returncode = p.returncode
 
         output = output.decode("utf-8").split('\n')
 
-        logger.info(f'rsync: {output[-3]}')
+        if returncode == 0:
-        logger.info(f'rsync: {output[-2]}')
+            if self._verbose:
+                logger.info('rsync: %s', output)
+            else:
+                logger.info('rsync: %s', output[-3])
+                logger.info('rsync: %s', output[-2])
+        else:
+            self._returncode_log(returncode)
 
-        if self.keep != -1 and not self.remove_before:
+            if self._verbose:
+                if returncode in [23, 24]:
+                    logger.warning(output)
+                else:
+                    logger.error(output)
+
+        if self.keep != -1 and not self._remove_before:
             self.remove_old_backups()
 
         os.remove(self._inputs_path)
         os.remove(self._exclude_path)
 
+        if self._remote:
+            assert self._ssh is not None
+
+            _, stdout, _ = self._ssh.exec_command(
+                f'if [ -d "{self._output_dir}" ]; then echo "ok"; fi')
+
+            output = stdout.read().decode('utf-8').strip()
+
+            if output == 'ok':
                 logger.info('Backup completed')
 
-        if self._err_flag:
+                try:
-            logger.warning('Some errors occurred (check log for details)')
+                    _notify('Backup completed')
+                except NameError:
+                    pass
+            else:
+                logger.error('Backup failed')
 
                 try:
-                notify('Backup finished with errors (check log for details)')
+                    _notify('Backup failed (check log for details)')
+                except NameError:
+                    pass
+
+            if self._ssh:
+                self._ssh.close()
+        else:
+            if returncode != 0:
+                logger.error(
+                    'Some errors occurred while performing the backup')
+
+                try:
+                    _notify(
+                        'Some errors occurred while performing the backup. Check log for details')
                 except NameError:
                     pass
 
                 return 4
-        else:
+
+            logger.info('Backup completed')
+
             try:
-                notify('Backup finished')
+                _notify('Backup completed')
             except NameError:
                 pass
 
             return 0
 
 
-def _parse_arguments():
+def _parse_arguments() -> argparse.Namespace:
+    euid = os.geteuid()
+
+    if euid == 0:
+        user = os.getenv('SUDO_USER')
+    else:
+        user = os.getenv('USER')
+
+    homedir = os.path.expanduser(f'~{user}')
+
     parser = argparse.ArgumentParser(prog='simple_backup',
                                      description='Simple backup script written in Python that uses rsync to copy files',
-                                     epilog='Report bugs to dfucini<at>gmail<dot>com',
+                                     epilog='See simple_backup(1) manpage for full documentation',
                                      formatter_class=MyFormatter)
 
+    parser.add_argument('-v', '--verbose', action='store_true',
+                        help='More verbose output')
     parser.add_argument('-c', '--config', default=f'{homedir}/.config/simple_backup/simple_backup.conf',
                         help='Specify location of configuration file')
-    parser.add_argument('-i', '--input', nargs='+', help='Paths/files to backup')
+    parser.add_argument('-i', '--inputs', nargs='+',
-    parser.add_argument('-o', '--output', help='Output directory for the backup')
+                        help='Paths/files to backup')
-    parser.add_argument('-e', '--exclude', nargs='+', help='Files/directories/patterns to exclude from the backup')
+    parser.add_argument(
-    parser.add_argument('-k', '--keep', type=int, help='Number of old backups to keep')
+        '-o', '--output', help='Output directory for the backup')
+    parser.add_argument('-e', '--exclude', nargs='+',
+                        help='Files/directories/patterns to exclude from the backup')
+    parser.add_argument('-k', '--keep', type=int,
+                        help='Number of old backups to keep')
+    parser.add_argument(
+        '-u', '--user', help='Explicitly specify the user running the backup')
     parser.add_argument('-s', '--checksum', action='store_true',
-                        help='Use checksum rsync option to compare files (MUCH SLOWER)')
+                        help='Use checksum rsync option to compare files')
+    parser.add_argument(
+        '--ssh-host', help='Server hostname (for remote backup)')
+    parser.add_argument(
+        '--ssh-user', help='Username to connect to server (for remote backup)')
+    parser.add_argument('--keyfile', help='SSH key location')
+    parser.add_argument('-z', '--compress', action='store_true',
+                        help='Compress data during the transfer')
     parser.add_argument('--remove-before-backup', action='store_true',
                         help='Remove old backups before executing the backup, instead of after')
-    parser.add_argument('--no-syslog', action='store_true', help='Disable systemd journal logging')
+    parser.add_argument('--no-syslog', action='store_true',
+                        help='Disable systemd journal logging')
+    parser.add_argument('--rsync-options', nargs='+',
+                        choices=['a', 'l', 'p', 't', 'g', 'o',
+                                 'c', 'h', 's', 'D', 'H', 'X'],
+                        help='Specify options for rsync')
+    parser.add_argument('--remote-sudo', action='store_true',
+                        help='Run rsync on remote server with sudo if allowed')
+    parser.add_argument('--numeric-ids', action='store_true',
+                        help='Use rsync \'--numeric-ids\' option (don\'t map uid/gid values by name)')
 
     args = parser.parse_args()
 
     return args
 
 
-def _expand_inputs(inputs):
+def _expand_inputs(inputs, user: Optional[str] = None):
     expanded_inputs = []
 
     for i in inputs:
         if i == '':
             continue
 
+        if user is not None:
             i_ex = glob(os.path.expanduser(i.replace('~', f'~{user}')))
+        else:
+            i_ex = glob(i)
+
+            if '~' in i:
+                logger.warning('Cannot expand \'~\'. No user specified')
 
         if len(i_ex) == 0:
-            logger.warning(f'No file or directory matching input {i}. Skipping...')
+            logger.warning(
+                'No file or directory matching input %s. Skipping...', i)
         else:
             expanded_inputs.extend(i_ex)
 
     return expanded_inputs
 
 
-def _read_config(config_file):
+def _read_config(config_file, user: Optional[str] = None):
-    if not os.path.isfile(config_file):
+    config_args = {'inputs': None,
-        logger.warning(f'Config file {config_file} does not exist')
+                   'output': None,
+                   'exclude': None,
+                   'keep': -1,
+                   'ssh_host': None,
+                   'ssh_user': None,
+                   'ssh_keyfile': None,
+                   'remote_sudo': False,
+                   'numeric_ids': False}
 
-        return None, None, None, None
+    if not os.path.isfile(config_file):
+        if user is not None:
+            logger.warning('Config file %s does not exist', config_file)
+        else:
+            logger.warning(
+                'User not specified. Can\'t read configuration file')
+
+        return config_args
 
     config = configparser.ConfigParser()
     config.read(config_file)
 
-    inputs = config.get('default', 'inputs')
+    section = 'backup'
+
+    # Allow compatibility with previous version of config file
+    try:
+        inputs = config.get(section, 'inputs')
+    except configparser.NoSectionError:
+        section = 'default'
+        inputs = config.get(section, 'inputs')
+
     inputs = inputs.split(',')
-    inputs = _expand_inputs(inputs)
+    inputs = _expand_inputs(inputs, user)
     inputs = list(set(inputs))
-    output = config.get('default', 'backup_dir')
+
+    config_args['inputs'] = inputs
+
+    output = config.get(section, 'backup_dir')
+
+    if user is not None:
         output = os.path.expanduser(output.replace('~', f'~{user}'))
-    exclude = config.get('default', 'exclude')
+    elif user is None and '~' in output:
+        logger.warning('Cannot expand \'~\', no user specified')
+
+    config_args['output'] = output
+
+    try:
+        exclude = config.get(section, 'exclude')
         exclude = exclude.split(',')
-    keep = config.getint('default', 'keep')
+    except configparser.NoOptionError:
+        exclude = []
 
-    return inputs, output, exclude, keep
+    config_args['exclude'] = exclude
+
+    try:
+        keep = config.getint(section, 'keep')
+    except configparser.NoOptionError:
+        keep = -1
+
+    config_args['keep'] = keep
+
+    try:
+        ssh_host = config.get('server', 'ssh_host')
+        ssh_user = config.get('server', 'ssh_user')
+    except (configparser.NoSectionError, configparser.NoOptionError):
+        ssh_host = None
+        ssh_user = None
+
+    config_args['ssh_host'] = ssh_host
+    config_args['ssh_user'] = ssh_user
+
+    try:
+        ssh_keyfile = config.get('server', 'ssh_keyfile')
+    except (configparser.NoSectionError, configparser.NoOptionError):
+        ssh_keyfile = None
+
+    config_args['ssh_keyfile'] = ssh_keyfile
+
+    try:
+        remote_sudo = config.getboolean('server', 'remote_sudo')
+    except (configparser.NoSectionError, configparser.NoOptionError):
+        remote_sudo = False
+
+    config_args['remote_sudo'] = remote_sudo
+
+    try:
+        numeric_ids = config.getboolean('server', 'numeric_ids')
+    except (configparser.NoSectionError, configparser.NoOptionError):
+        numeric_ids = False
+
+    config_args['numeric_ids'] = numeric_ids
+
+    return config_args
 
 
-def notify(text):
+def _notify(text: str) -> None:
     euid = os.geteuid()
 
     if euid == 0:
         uid = os.getenv('SUDO_UID')
     else:
-        uid = os.geteuid()
+        uid = euid
+
+    if uid is None:
+        return
 
     os.seteuid(int(uid))
     os.environ['DBUS_SESSION_BUS_ADDRESS'] = f'unix:path=/run/user/{uid}/bus'
 
-    obj = dbus.SessionBus().get_object('org.freedesktop.Notifications', '/org/freedesktop/Notifications')
+    obj = dbus.SessionBus().get_object('org.freedesktop.Notifications',
+                                       '/org/freedesktop/Notifications')
     obj = dbus.Interface(obj, 'org.freedesktop.Notifications')
     obj.Notify('', 0, '', 'simple_backup', text, [], {'urgency': 1}, 10000)
 
     os.seteuid(int(euid))
 
 
-def simple_backup():
+def simple_backup() -> int:
+    """Main"""
+
     args = _parse_arguments()
 
+    if args.user:
+        user = args.user
+        homedir = os.path.expanduser(f'~{user}')
+    else:
+        euid = os.geteuid()
+
+        if euid == 0:
+            user = os.getenv('SUDO_USER')
+
+            if user is not None:
+                homedir = os.path.expanduser(f'~{user}')
+            else:
+                logger.warning(
+                    'Failed to detect user. You can use -u/--user parameter to manually specify it')
+                homedir = None
+        else:
+            user = os.getenv('USER')
+            homedir = os.getenv('HOME')
+
+    if homedir is None:
+        homedir = ''
+
     if args.no_syslog:
         try:
             logger.removeHandler(j_handler)
         except NameError:
             pass
 
-    inputs, output, exclude, keep = _read_config(args.config)
+    try:
+        config_args = _read_config(args.config, user)
+    except (configparser.NoSectionError, configparser.NoOptionError):
+        logger.critical('Bad configuration file')
 
-    if args.input is not None:
+        return 6
-        inputs = args.input
 
-    if args.output is not None:
+    inputs = args.inputs if args.inputs is not None else config_args['inputs']
-        output = args.output
+    output = args.output if args.output is not None else config_args['output']
+    exclude = args.exclude if args.exclude is not None else config_args['exclude']
+    keep = args.keep if args.keep is not None else config_args['keep']
+    ssh_host = args.ssh_host if args.ssh_host is not None else config_args['ssh_host']
+    ssh_user = args.ssh_user if args.ssh_user is not None else config_args['ssh_user']
+    ssh_keyfile = args.keyfile if args.keyfile is not None else config_args['ssh_keyfile']
+    remote_sudo = args.remote_sudo or config_args['remote_sudo']
 
-    if args.exclude is not None:
+    if args.rsync_options is None:
-        exclude = args.exclude
+        rsync_options = ['-a', '-r', '-v', '-h', '-H',
+                         '-X', '-s', '--ignore-missing-args', '--mkpath']
+    else:
+        rsync_options = ['-r', '-v']
 
-    if args.keep is not None:
+        for ro in args.rsync_options:
-        keep = args.keep
+            rsync_options.append(f'-{ro}')
 
     if args.checksum:
-        backup_options = '-arcvh -H -X'
+        rsync_options.append('-c')
-    else:
-        backup_options = '-arvh -H -X'
 
-    backup = Backup(inputs, output, exclude, keep, backup_options, remove_before=args.remove_before_backup)
+    if args.compress:
+        rsync_options.append('-z')
 
-    return_code = backup.check_params()
+    if args.numeric_ids or config_args['numeric_ids']:
+        rsync_options.append('--numeric-ids')
+
+    rsync_options = ' '.join(rsync_options)
+
+    backup = Backup(inputs, output, exclude, keep, rsync_options, ssh_host, ssh_user, ssh_keyfile,
+                    remote_sudo, remove_before=args.remove_before_backup, verbose=args.verbose)
+
+    return_code = backup.check_params(homedir)
 
     if return_code == 0:
         return backup.run()