使用Paramiko一次创建多个SSH连接

Question

下面的代码通过SSH在一台计算机上运行grep并打印结果：

import sys, os, string
import paramiko

cmd = "grep -h 'king' /opt/data/horror_20100810*"

ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('10.10.3.10', username='xy', password='xy')
stdin, stdout, stderr = ssh.exec_command(cmd)
stdin.write('xy\n')
stdin.flush()

print stdout.readlines()

我如何一次将5台机器全部置入grep（这样就不会造成重大延迟），而不是将所有这些都放入5个变量中并全部打印出来。

Answer 1

您需要将调用放在单独的线程（或进程中，但这可能会过大），这反过来又要求代码位于函数中（无论如何，这是一个好主意：模块的顶部没有大量代码水平）。

例如：

import sys, os, string, threading
import paramiko

cmd = "grep -h 'king' /opt/data/horror_20100810*"

outlock = threading.Lock()

def workon(host):

    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect(host, username='xy', password='xy')
    stdin, stdout, stderr = ssh.exec_command(cmd)
    stdin.write('xy\n')
    stdin.flush()

    with outlock:
        print stdout.readlines()

def main():
    hosts = ['10.10.3.10', '10.10.4.12', '10.10.2.15', ] # etc
    threads = []
    for h in hosts:
        t = threading.Thread(target=workon, args=(h,))
        t.start()
        threads.append(t)
    for t in threads:
        t.join()

main()

If you had many more than five hosts, I would recommend using instead a
“thread pool” architecture and a queue of work units. But, for just five, it’s
simpler to stick to the “dedicated thread” model (especially since there is no
thread pool in the standard library, so you’d need a third party package like
threadpool… or a lot of
subtle custom code of your own of course;-).