1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
# ssh.py - Interact with remote SSH servers
#
# Copyright 2019 Gregory Szorc <gregory.szorc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
# no-check-code because Python 3 native.
import socket
import time
import warnings
from cryptography.utils import CryptographyDeprecationWarning
import paramiko
def wait_for_ssh(hostname, port, timeout=60, username=None, key_filename=None):
"""Wait for an SSH server to start on the specified host and port."""
class IgnoreHostKeyPolicy(paramiko.MissingHostKeyPolicy):
def missing_host_key(self, client, hostname, key):
return
end_time = time.time() + timeout
# paramiko triggers a CryptographyDeprecationWarning in the cryptography
# package. Let's suppress
with warnings.catch_warnings():
warnings.filterwarnings(
'ignore', category=CryptographyDeprecationWarning
)
while True:
client = paramiko.SSHClient()
client.set_missing_host_key_policy(IgnoreHostKeyPolicy())
try:
client.connect(
hostname,
port=port,
username=username,
key_filename=key_filename,
timeout=5.0,
allow_agent=False,
look_for_keys=False,
)
return client
except OSError:
pass
except paramiko.AuthenticationException:
raise
except paramiko.SSHException:
pass
if time.time() >= end_time:
raise Exception('Timeout reached waiting for SSH')
time.sleep(1.0)
def exec_command(client, command):
"""exec_command wrapper that combines stderr/stdout and returns channel"""
chan = client.get_transport().open_session()
chan.exec_command(command)
chan.set_combine_stderr(True)
stdin = chan.makefile('wb', -1)
stdout = chan.makefile('r', -1)
return chan, stdin, stdout
|
