Coverage for .tox/coverage/lib/python3.11/site-packages/wuttamess/ssh.py: 100%

1# -*- coding: utf-8; -*- 

2################################################################################ 

3# 

4# WuttaMess -- Fabric Automation Helpers 

5# Copyright © 2024 Lance Edgar 

6# 

7# This file is part of Wutta Framework. 

8# 

9# Wutta Framework is free software: you can redistribute it and/or modify it 

10# under the terms of the GNU General Public License as published by the Free 

11# Software Foundation, either version 3 of the License, or (at your option) any 

12# later version. 

13# 

14# Wutta Framework is distributed in the hope that it will be useful, but 

15# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 

16# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 

17# more details. 

18# 

19# You should have received a copy of the GNU General Public License along with 

20# Wutta Framework. If not, see <http://www.gnu.org/licenses/>. 

21# 

22################################################################################ 

23""" 

24SSH Utilities 

25""" 

26 

27 

28def cache_host_key(c, host, port=None, user=None): 

29 """ 

30 Cache the SSH host key for the given host, for the given user. 

31 

32 :param c: Fabric connection. 

33 

34 :param host: Name or IP of the host whose key should be cached. 

35 

36 Note that you can specify a username along with the hostname if 

37 needed, e.g. any of these works: 

38 

39 * ``1.2.3.4`` 

40 * ``foo@1.2.3.4`` 

41 * ``example.com`` 

42 * ``foo@example.com`` 

43 

44 :param port: Optional SSH port for the ``host``; default is 22. 

45 

46 :param user: User on the fabric target whose SSH key cache should 

47 be updated to include the given ``host``. 

48 """ 

49 port = f'-p {port} ' if port else '' 

50 

51 # first try to run a basic command over ssh 

52 cmd = f'ssh {port}{host} whoami' 

53 if user and user != 'root': 

54 result = c.sudo(cmd, user=user, warn=True) 

55 else: 

56 result = c.run(cmd, warn=True) 

57 

58 # no need to update cache if command worked okay 

59 if not result.failed: 

60 return 

61 

62 # basic command failed, but in some cases that is simply b/c 

63 # normal commands are not allowed, although the ssh connection 

64 # itself was established okay. so here we check for that. 

65 if "Disallowed command" in result.stderr: 

66 return 

67 

68 # okay then we now think that the ssh connection itself 

69 # was not made, which presumably means we *do* need to 

70 # cache the host key, so try that now 

71 cmd = f'ssh -o StrictHostKeyChecking=no {port}{host} whoami' 

72 if user and user != 'root': 

73 c.sudo(cmd, user=user, warn=True) 

74 else: 

75 c.run(cmd, warn=True)