python-pexpect和ssh:如何在su-root -c之后格式化命令字符串
作者:互联网
我正在尝试遍历服务器列表和密码来更改一组服务器上的sshd配置,以便我可以使用无密码的SSH密钥通过root登录/运行命令.
我可以在bash中轻松完成此操作,但是我正在尝试学习Python,并且(显然)希望放弃手动输入密码.
这是我想做的事:
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
当我运行该命令时,COMMAND1(scp’ing)工作正常.
但是COMMAND2失败:
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 $)
command: /usr/bin/ssh
args: ['/usr/bin/ssh', '-o', 'StrictHostKeyChecking=no', '-t', 'user@192.168.1.1', 'su - root -c chown', 'root:root', '/tmp/id_rsa.pub;', 'chmod', '600', '/tmp/id_rsa.pub;', 'chown', 'root:root', '/tmp/sshd_config;', 'mkdir', '/root/.ssh;', 'chown', 'root:root', '/root/.ssh;', 'chmod', '700', '/root/.ssh;', 'mv', '/tmp/id_rsa.pub', '/root/.ssh/authorized_keys;', 'mv', '/tmp/sshd_config', '/etc/ssh/;', 'service', 'sshd', 'reload']
searcher: searcher_re:
0: EOF
buffer (last 100 chars): : Permission denied
mv: try to overwrite `/etc/ssh/sshd_config', overriding mode 0600 (rw-------)?
before (last 100 chars): : Permission denied
mv: try to overwrite `/etc/ssh/sshd_config', overriding mode 0600 (rw-------)?
after: <class 'pexpect.TIMEOUT'>
match: None
match_index: None
exitstatus: None
flag_eof: False
pid: 3612
child_fd: 4
closed: False
timeout: 30
delimiter: <class 'pexpect.EOF'>
logfile: None
logfile_read: None
logfile_send: None
maxread: 2000
ignorecase: False
searchwindowsize: None
delaybeforesend: 0.05
delayafterclose: 0.1
delayafterterminate: 0.1
如果在运行脚本之前删除远程服务器上的/ etc / ssh / sshd_config文件,则会得到:
server1:ssh-pexpect user$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.
我什至不知道如何调试它以查看它的混乱情况.不过,我认为它无法正确解析COMMAND2.
对于Python来说还很陌生,因此欢迎您提出建议.
谢谢.
解决方法:
您在COMMAND2中使用了双引号,并正确地转义了所有嵌入的双引号,但是您还需要对所有已经转义的双引号进行转义.换句话说,这并不是真正的Python问题.不过,您可以将Python三重引号用作最外面的引号.它也会更容易阅读.
编辑:实际上,对引用进行任何适当的歧义都可以.由于外壳程序也提供单引号,因此带单引号的解决方案很好. Python将允许您使用单引号或许多其他引号工具,如果您尚未解决此问题,我会建议您使用它(因为这样您可以选择不需要对字符串本身进行任何更改的引号;较少的空间)错误).
因此,以下任何一项都可以:
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,以消除相邻的双引号的歧义.但是您可以使用三重单引号代替.另外,三引号(单引号或双引号)使您可以插入换行符,从而大大提高了可读性:
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)
标签:pexpect,ssh,python 来源: https://codeday.me/bug/20191101/1985863.html