Fix crash when config file missing

man/simple_backup.1

@@ -172,6 +172,12 @@ Permission denied to access the output directory
 .TP
 .B 4
 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

simple_backup/simple_backup.py

@@ -29,11 +29,16 @@ from getpass import getpass
 from glob import glob
 
 from dotenv import load_dotenv
-import paramiko
-from paramiko import RSAKey, Ed25519Key, ECDSAKey, DSSKey
 
 warnings.filterwarnings('error')
 
+try:
+    raise ImportError
+    import paramiko
+    from paramiko import RSAKey, Ed25519Key, ECDSAKey, DSSKey
+except ImportError:
+    pass
+
 try:
     from systemd import journal
 except ImportError:
@@ -181,7 +186,7 @@ class Backup:
             self._ssh = self._ssh_connect()
 
             if self._ssh is None:
-                sys.exit(1)
+                sys.exit(5)
 
             _, stdout, _ = self._ssh.exec_command(f'if [ -d "{self.output}" ]; then echo "ok"; fi')
 
@@ -279,7 +284,7 @@ class Backup:
         if self._remote:
             if self._ssh is None:
                 logger.critical('SSH connection to server failed')
-                sys.exit(1)
+                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')
@@ -311,7 +316,11 @@ class Backup:
                 logger.info('No previous backups available')
 
     def _ssh_connect(self):
+        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')
@@ -597,7 +606,15 @@ def _expand_inputs(inputs):
 
 
 def _read_config(config_file):
-    config_args = {}
+    config_args = {'inputs': None,
+                   'output': None,
+                   'exclude': None,
+                   'keep': -1,
+                   'host': None,
+                   'username': None,
+                   'ssh_keyfile': None,
+                   'remote_sudo': False,
+                   'numeric_ids': False}
 
     if not os.path.isfile(config_file):
         logger.warning('Config file %s does not exist', config_file)
@@ -709,7 +726,7 @@ def simple_backup():
         config_args = _read_config(args.config)
     except (configparser.NoSectionError, configparser.NoOptionError):
         logger.critical('Bad configuration file')
-        sys.exit(1)
+        sys.exit(6)
 
     inputs = args.inputs if args.inputs is not None else config_args['inputs']
     output = args.output if args.output is not None else config_args['output']