Question

我一直在尝试使用paramiko在Overture Box上运行命令来建立SSH连接。

我的脚本确实正确连接到框，没有看到任何问题，当脚本运行exec_command（cmd）方法时出现问题：

Traceback (most recent call last):
  File "test.py", line 39, in <module>
    stdin, stdout, stderr = ssh.exec_command("version")
  File "/opt/csw/lib/python2.7/site-packages/paramiko/client.py", line 345, in exec_command
    chan.exec_command(command)
  File "/opt/csw/lib/python2.7/site-packages/paramiko/channel.py", line 60, in _check
    return func(self, *args, **kwds)
  File "/opt/csw/lib/python2.7/site-packages/paramiko/channel.py", line 229, in exec_command
    self._wait_for_event()
  File "/opt/csw/lib/python2.7/site-packages/paramiko/channel.py", line 1086, in _wait_for_event
    raise e
paramiko.ssh_exception.SSHException: Channel closed.

使用Linux Box作为目标主机的相同脚本产生正确的结果

代码被借用了，我刚刚找到了Googling代码：

import sys
import time
import select
import paramiko

host = raw_input("Hostname?: ")
i = 1
password = raw_input("Password?: ")


#
# Try to connect to the host.
# Retry a few times if it fails.
#
while True:
    print "Trying to connect to %s (%i/30)" % (host, i)

    try:
        ssh = paramiko.SSHClient()
        ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        ssh.connect(host, port=22, username="username", password=password)
        print "Connected to %s" % host
        break
    except paramiko.AuthenticationException:
        print "Authentication failed when connecting to %s" % host
        sys.exit(1)
    except:
        print "Could not SSH to %s, waiting for it to start" % host
        i += 1
        time.sleep(2)

    # If we could not connect within time limit
    if i == 30:
        print "Could not connect to %s. Giving up" % host
        sys.exit(1)

# Send the command (non-blocking)
stdin, stdout, stderr = ssh.exec_command("version")

# Wait for the command to terminate
while not stdout.channel.exit_status_ready():
    # Only print data if there is data to read in the channel
    if stdout.channel.recv_ready():
        rl, wl, xl = select.select([stdout.channel], [], [], 0.0)
        if len(rl) > 0:
           # Print data from stdout
            print stdout.channel.recv(1024),

#
# Disconnect from the host
#
print "Command done, closing SSH connection"
ssh.close()

我发现其他问题表明该问题可能与主机中的SFTP设置有关，但我能够做到：

sftp username@hostname

我已经搜索了一段时间，但到目前为止我找不到任何有用的信息。

提前感谢您的帮助。

编辑：差点忘了，我知道问题正是在：

stdin, stdout, stderr = ssh.exec_command("version")

我以交互方式运行整个脚本，当我运行该行时，它会中断。

Answer 1

可能是Overture不支持SSH exec_command请求。

我需要使用transport.open_session()，session.get_pty()和session.invoke_shell()来设置交互式shell会话，然后使用session.send()和session.recv()来编写/读取当exec_command()不可用时，到Cisco交换机和其他网络设备的shell会话。

Answer 2

这是解决此问题的方法，

获取连接的传输方式。
打开会话。
然后func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool { // Override point for customization after application launch. return true } func application(_ app: UIApplication, open url: URL, options: [UIApplication.OpenURLOptionsKey : Any] = [:]) -> Bool { if let authorizationFlow = self.currentAuthorizationFlow, authorizationFlow.resumeExternalUserAgentFlow(with: url){ self.currentAuthorizationFlow = nil return true } return false } recv（）`，无需睡觉。
```
exec_command(command) and then
```

Paramiko问题 - 执行命令时频道关闭

2 个答案: