Question

我正在尝试遍历一系列服务器＆amp;密码更改一组服务器上的sshd配置，以便我可以使用无密码SSH密钥通过root登录/运行命令。

我可以在bash中轻松完成这项工作，但我正在尝试学习Python，并且（显然）想放弃手动输入密码。

以下是我想要做的事情：

scp ~/.ssh/id_rsa.pub /etc/ssh/sshd_config USER@IP:/tmp/

ssh -o StrictHostKeyChecking=no -t USER@IP "su - root -c \"chown root:root /tmp/id_rsa.pub; chmod 600 /tmp/id_rsa.pub; chown root:root /tmp/sshd_config; mkdir /root/.ssh; chown root:root /root/.ssh; chmod 700 /root/.ssh; mv /tmp/id_rsa.pub /root/.ssh/authorized_keys; mv /tmp/sshd_config /etc/ssh/; service sshd reload\""

我已经接近使用pexpect在Python中执行此操作：

import pexpect

USER="user"
HOST="192.168.1.1"
USERPASS="userpass" 
ROOTPASS="rootpass"

COMMAND1="scp /Users/user/.ssh/id_rsa.pub /Users/user/github/ssh-pexpect/sshd_config %s@%s:/tmp/" % (USER, HOST)

COMMAND2="ssh -o StrictHostKeyChecking=no -t %s@%s \"su - root -c \"chown root:root /tmp/id_rsa.pub; chmod 600 /tmp/id_rsa.pub; chown root:root /tmp/sshd_config; mkdir /root/.ssh; chown root:root /root/.ssh; chmod 700 /root/.ssh; mv /tmp/id_rsa.pub /root/.ssh/authorized_keys; mv /tmp/sshd_config /etc/ssh/; service sshd reload\"\"" % (USER, HOST)

child = pexpect.spawn(COMMAND1)
child.expect('password:')
child.sendline(USERPASS)
child.expect(pexpect.EOF)
print child.before

child = pexpect.spawn(COMMAND2)
child.expect('password:')
child.sendline(USERPASS)
child.expect('Password:')
child.sendline(ROOTPASS)
child.expect(pexpect.EOF)
print child.before

当我运行COMMAND1（scp'ing）时工作正常。但是COMMAND2失败了：

server1:ssh-pexpect user$ python test4.py 

id_rsa.pub                                    100%  410     0.4KB/s   00:00    
sshd_config                                   100% 3498     3.4KB/s   00:00    

Traceback (most recent call last):
  File "test4.py", line 25, in <module>
    child.expect(pexpect.EOF)
  File "/Library/Python/2.7/site-packages/pexpect.py", line 1316, in expect
    return self.expect_list(compiled_pattern_list, timeout, searchwindowsize)
  File "/Library/Python/2.7/site-packages/pexpect.py", line 1330, in expect_list
    return self.expect_loop(searcher_re(pattern_list), timeout, searchwindowsize)
  File "/Library/Python/2.7/site-packages/pexpect.py", line 1414, in expect_loop
    raise TIMEOUT (str(e) + '\n' + str(self))
pexpect.TIMEOUT: Timeout exceeded in read_nonblocking().
<pexpect.spawn object at 0x102b796d0>
version: 2.4 ($Revision: 516 $)
command: /usr/bin/ssh
args: ['/usr/bin/ssh', '-o', 'StrictHostKeyChecking=no', '-t', 'user@192.168.1.1', 'su - root -c chown', 'root:root', '/tmp/id_rsa.pub;', 'chmod', '600', '/tmp/id_rsa.pub;', 'chown', 'root:root', '/tmp/sshd_config;', 'mkdir', '/root/.ssh;', 'chown', 'root:root', '/root/.ssh;', 'chmod', '700', '/root/.ssh;', 'mv', '/tmp/id_rsa.pub', '/root/.ssh/authorized_keys;', 'mv', '/tmp/sshd_config', '/etc/ssh/;', 'service', 'sshd', 'reload']
searcher: searcher_re:
    0: EOF
buffer (last 100 chars): : Permission denied
mv: try to overwrite `/etc/ssh/sshd_config', overriding mode 0600 (rw-------)? 
before (last 100 chars): : Permission denied
mv: try to overwrite `/etc/ssh/sshd_config', overriding mode 0600 (rw-------)? 
after: <class 'pexpect.TIMEOUT'>
match: None
match_index: None
exitstatus: None
flag_eof: False
pid: 3612
child_fd: 4
closed: False
timeout: 30
delimiter: <class 'pexpect.EOF'>
logfile: None
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1

如果在运行脚本之前删除远程服务器上的/ etc / ssh / sshd_config文件，我会得到：

server1:ssh-pexpect user$ python test4.py  
id_rsa.pub                                    100%  410     0.4KB/s   00:00    
sshd_config                                   100% 3498     3.4KB/s   00:00    


chown: missing operand
Try `chown --help' for more information.
chown: changing ownership of `/tmp/sshd_config': Operation not permitted
mkdir: cannot create directory `/root/.ssh': Permission denied
chown: cannot access `/root/.ssh': Permission denied
chmod: cannot access `/root/.ssh': Permission denied
mv: accessing `/root/.ssh/authorized_keys': Permission denied
mv: cannot move `/tmp/sshd_config' to `/etc/ssh/sshd_config': Permission denied
bash: service: command not found
Connection to 192.168.1.1 closed.

我甚至不确定如何调试它以查看它在哪里弄乱。不过，我认为它不能正确解析COMMAND2。对Python来说很新，所以任何建议都值得赞赏。感谢。

Answer 1

你有双引号的COMMAND2并且正确地转义任何嵌入的双引号，但你还需要双重转义任何已经转义的双引号。换句话说，不是真正的Python问题。不过，您可以切换到最外层引号的Python三引号。它也会更容易阅读。

编辑：实际上，任何适当的报价消歧都可以。由于shell也提供单引号，因此使用单引号的解决方案很好。 Python会允许你使用单引号或许多其他引用工具，如果你还没有解决问题我会推荐（因为那时你可以选择不需要对字符串本身进行任何更改的引号;更少的空间为了错误）。

所以，其中任何一个都应该没问题：

COMMAND2='ssh -o StrictHostKeyChecking=no -t %s@%s "su - root -c \"chown root:root /tmp/id_rsa.pub; chmod 600 /tmp/id_rsa.pub; chown root:root /tmp/sshd_config; mkdir /root/.ssh; chown root:root /root/.ssh; chmod 700 /root/.ssh; mv /tmp/id_rsa.pub /root/.ssh/authorized_keys; mv /tmp/sshd_config /etc/ssh/; service sshd reload\""' % (USER, HOST)

COMMAND2="""ssh -o StrictHostKeyChecking=no -t %s@%s "su - root -c \"chown root:root /tmp/id_rsa.pub; chmod 600 /tmp/id_rsa.pub; chown root:root /tmp/sshd_config; mkdir /root/.ssh; chown root:root /root/.ssh; chmod 700 /root/.ssh; mv /tmp/id_rsa.pub /root/.ssh/authorized_keys; mv /tmp/sshd_config /etc/ssh/; service sshd reload\"" """ % (USER, HOST)

COMMAND2="ssh -o StrictHostKeyChecking=no -t %s@%s 'su - root -c \"chown root:root /tmp/id_rsa.pub; chmod 600 /tmp/id_rsa.pub; chown root:root /tmp/sshd_config; mkdir /root/.ssh; chown root:root /root/.ssh; chmod 700 /root/.ssh; mv /tmp/id_rsa.pub /root/.ssh/authorized_keys; mv /tmp/sshd_config /etc/ssh/; service sshd reload\"'" % (USER, HOST)

我需要在三引号中添加一个空格，以消除相邻双引号的歧义。但你可以改用三重单引号。此外，三重引号（单引号或双引号）允许您嵌入换行符，从而显着提高易读性：

COMMAND2='''ssh -o StrictHostKeyChecking=no -t %s@%s "su - root -c '
    chown root:root /tmp/id_rsa.pub
    chmod 600 /tmp/id_rsa.pub
    chown root:root /tmp/sshd_config
    mkdir /root/.ssh
    chown root:root /root/.ssh
    chmod 700 /root/.ssh
    mv /tmp/id_rsa.pub /root/.ssh/authorized_keys
    mv /tmp/sshd_config /etc/ssh/
    service sshd reload'"''' % (USER, HOST)

Answer 2

我最终选择单引号而不是试图弄清楚如何逃避双引号：

COMMAND2="ssh -o StrictHostKeyChecking=no -t %s@%s \"su - root -c 'chown root:root /tmp/id_rsa.pub; chmod 600 /tmp/id_rsa.pub; chown root:root /tmp/sshd_config; mkdir /root/.ssh; chown root:root /root/.ssh; chmod 700 /root/.ssh; mv /tmp/id_rsa.pub /root/.ssh/authorized_keys; mv /tmp/sshd_config /etc/ssh/; service sshd reload'\"" % (USER, HOST)

pexpect和ssh：如何在su - root -c之后格式化一串命令

2 个答案: