paramiko 的 SSHClient.Close() 方法需要等待吗？

Question

每个人。

我在窗口 7 x64 上使用带有 python 3.3.3 x64 的 parmiko，以下是我的代码，奇怪的是我需要在使用 client.close() 结束会话之前添加 time.sleep(0.01) 延迟.否则SSH主机会存在很多进程，无法自动结束。

谁能帮我解释一下这些？ 用于 python3 的 paramiko： (https://travis-ci.org/nischu7/paramiko)

重复的步骤如下： A) 去掉 client.close() 之前的 time.sleep(0.01) 并运行脚本

B)输入 SSH 主机的密码

C)输入第一条命令，例如：ls -la

D) 非常频繁地键入命令，例如，按住向上箭头并多次输入交替非常快

E)当使用 ps -ef | grep dropbear（SSH服务器，OpenSSH我没测试过），存在很多进程

F) 键入 exit 和 Ctrl + Z 以终止脚本

G)在 client.close() 之前保持 time.sleep(0.01) 并再次运行脚本

H) 执行上述 B、C、D 步骤，然后用 ps -ef | 检查再次grep dropbear，这个脚本只会生成一个SSH进程。

这里是代码：

from tkinter import *

from threading import Thread
from queue import Queue, Empty

import _thread
import time

from paramiko import SSHClient, Transport, AutoAddPolicy, WarningPolicy
import getpass      

def start(client):
    try :
        client.connect(hostname='127.0.0.1', port=22, username='ubuntu', password=pw)
        return True
    except Exception as e:
        client.close()
        print(e)
        return False

def check(client,outqueue):
    while start(client):
        outqueue.put("Command to run: ")
        cmd = input()
        if cmd == "exit":
            client.close()
            break
        chan = client.get_transport().open_session()
        outqueue.put("running '%s'" % cmd)
        chan.exec_command(cmd)
        while True:
            if chan.recv_ready():
                data = chan.recv(4096).decode('ascii')
                outqueue.put("recv:\n%s" %data)
            if chan.recv_stderr_ready():
                error = chan.recv_stderr(4096).decode('ascii')
                outqueue.put("error:\n%s" %error)
            if chan.exit_status_ready():
                exitcode = chan.recv_exit_status()
                outqueue.put("exit status: %s" %exitcode)
                #print('close s')
                #print(client.close())
                time.sleep(0.01)
                client.close()
                #print('close e')
                #time.sleep(0.05)
                break

def reader(outqueue):
    while True:
        while outqueue.qsize():
            try:
                data = outqueue.get()
                if data:
                    print(data)
            except Excetpiton as e:
                print(e)
                #continue
        #time.sleep(0.5)

if __name__=='__main__':
    pw = getpass.getpass()
    client = SSHClient()
    client.set_missing_host_key_policy(WarningPolicy())
    #client.set_missing_host_key_policy(AutoAddPolicy())    
    outqueue = Queue()

    r = Thread(target=reader,args=(outqueue,))
    r.daemon = True
    r.start()

    t = Thread(target=check,args=(client,outqueue,))
    #t.daemon = True
    t.start()
    t.join()

Answer 1

这是一个错误，我多次启动客户端，所以通过以下方式解决：

from threading import Thread
from queue import Queue, Empty

import _thread
import time

from paramiko import SSHClient, Transport, AutoAddPolicy, WarningPolicy
import getpass      

def start(client):
    try :
        client.connect(hostname='127.0.0.1', port=22, username='ubuntu', password=pw)
        return True
    except Exception as e:
        client.close()
        print(e)
        return False

def check(client,outqueue): 
    while True:
        outqueue.put("Command to run: ")
        cmd = input()
        if cmd == "exit":
            client.close()
            break
        chan = client.get_transport().open_session()
        outqueue.put("running '%s'" % cmd)
        chan.exec_command(cmd)
        while True:
            if chan.recv_ready():
                data = chan.recv(4096).decode('ascii')
                outqueue.put("recv:\n%s" %data)
            if chan.recv_stderr_ready():
                error = chan.recv_stderr(4096).decode('ascii')
                outqueue.put("error:\n%s" %error)
            if chan.exit_status_ready():
                exitcode = chan.recv_exit_status()
                outqueue.put("exit status: %s" %exitcode)
                #print('close s')
                #print(client.close())
                #time.sleep(0.01)
                #client.close()
                #print('close e')
                #time.sleep(0.05)
                break

def reader(outqueue):
    while True:
        while outqueue.qsize():
            try:
                data = outqueue.get()
                if data:
                    print(data)
            except Excetpiton as e:
                print(e)
                #continue
        #time.sleep(0.5)

if __name__=='__main__':
    pw = getpass.getpass()
    client = SSHClient()
    client.set_missing_host_key_policy(WarningPolicy())
    #client.set_missing_host_key_policy(AutoAddPolicy())

    if not start(client):
        #os._exit(0)
        sys.exit(0)

    outqueue = Queue()

    r = Thread(target=reader,args=(outqueue,))
    r.daemon = True
    r.start()

    t = Thread(target=check,args=(client,outqueue,))
    #t.daemon = True
    t.start()
    t.join()