https://www.jianshu.com/p/944674f44b24
paramiko 是 Python 中的一个用来连接远程主机的第三方工具，通过使用 paramiko 可以用来代替以 ssh 连接到远程主机执行命令。
paramiko 模块提供了两个核心组件，分别是 SSHClient 和 SFTPClient。前者用于在远程主机上执行命令，是对于 ssh 会话的封装；后者用于对资源上传下载等操作，是对 sftp 的封装。
paramiko 模块提供了一些SSH核心组件
Channel: 建立 ssh 连接后，paramiko会调用底层的 channel 类来打开一个socket连接，后续发送的命令会通过 channel 进行发送，当接收到命令的返回结果(标准输出或标准错误)后，结果又将通过 channel 发送到连接的客户端。Client: 建立的 ssh 会话的客户端。通过客户端可以去连接多个远程主机，并将执行的命令通过 client.exec_command() 方法发送到远程主机。Message: 一个用来将传输过程中的字符、整形、布尔及长类型的字符组合进行编码组成的字节流信息。Packetizer: Implementation of the base SSH packet protocol.Transport: 封装了一个加密的会话，调用该会话时会创建一个流式隧道(通常称为 channel)封装的具体逻辑，为了保持功能的纯粹性，仅通过 paramiko 实现客户端的的建立及命令的发送。
以下为实现逻辑
#!/usr/bin/env python3
# coding=utf-8
import sys
import socket
import paramiko
from paramiko.ssh_exception import NoValidConnectionsError, AuthenticationException
class Connect(object):
def __init__(self, username: str,
password: str,
port: int = 22,
hostname: str,
pkey: str = None,
look_for_keys: bool = True,
allow_agent: bool = True,
timeout: float = None
):
self.hostname = hostname
self.username = suername
self.port = port
self.password = password
self.pkey = pkey
self.allow_agent = allow_agent
self.look_for_keys = look_for_keys
self.timeout = timeout
def _connect(self):
self.client = SSHClient()
self.client.load_system_host_keys()
self.client.set_missing_host_key_policy(paramiko.AutoAddpolicy())
try:
self.client.connect(hostname=self.hostname,
port=self.port,
username=self.username,
password=self.password,
pkey=self.pkey,
allow_agent=self.allow_agent,
look_for_keys=self.look_for_keys
)
except BadHostKeyException as badKey:
msg = "Receive a bad key"
sys.exit()
except AuthenticationException as auth:
msg = "Invalid username or password"
sys.exit()
except SSHExpection as ssh:
msg = "Establish ssh session error"
sys.exit()
exception scoket.error as sock:
msg = "Connecting has a socket error"
sys.exit()
def run(self, command: str):
stdin, stdout, stderr = self.client.exec_command(command, timeout=self.timeout)
stdin.close()
stdout.flush()
try:
output = stdout.read()
err_msg = stderr.read()
output = output.decode("utf-8") if isinstance(output, bytes) else output
err_msg = err_msg.decode("utf-8") if isinstance(err_msg, bytes) else err_msg
return output, err_msg
except socket.timeout:
raise(f"Exec Command {command} timeout")
def close(self):
self.client.close()
将ssh会话保存到会话池中
#!/usr/bin/env python3
# encoding=utf-8
import os
import socket
import paramiko
from collections import deque
from paramiko.ssh_exception import SSHException
from paramiko.ssh_exception import NoValidConnectionsError, AuthenticationException
from eventlet import pools
class SSHPool(pools.Pool):
"""创建 SSH 对象池 """
_pool = deque()
def __init__(self,
ip: str,
username: str,
password: str = None,
port: int = 22,
privatekey: str = None,
timeout: float = None,
**kwargs
):
self.ip = ip
self.port = port
self.password = password
self.username = username
self.privatekey = privatekey
self.timeout = timeout
super(SSHPool, self).__init__(**kwargs)
def create(self):
try:
client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
if self.password:
client.connect(self.ip,
port=self.port,
username=self.username,
password=self.password,
timeout=self.timeout
)
elif self.privatekey:
if isinstance(self.privatekey, paramiko.rsakey.RSAKey):
key = self.privatekey
else:
keyfile = os.path.expanduser(self.privatekey)
key = paramiko.RSAKey.from_private_key_file(keyfile)
client.connect(self.ip,
port=self.port,
username=self.username,
look_for_keys=True,
pkey=key,
timeout=self.timeout
)
else:
raise SSHException("Invalid username or password")
# Paramiko by default sets the socket timeout to 0.1 seconds,
# ignoring what we set through the sshclient. This doesn't help for
# keeping long lived connections. Hence we have to bypass it, by
# overriding it after the transport is initialized. We are setting
# the sockettimeout to None and setting a keepalive packet so that,
# the server will keep the connection open. All that does is send
# a keepalive packet every ssh_conn_timeout seconds.
if self.timeout:
transport = client.get_transport()
transport.sock.settimeout(None)
transport.set_keepalive(self.timeout)
return client
except socket.timeout:
raise SSHException("Connect timeout")
except NoValidConnectionsError as novalid:
raise SSHException("Connect valid failed")
except AuthenticationException as auth:
raise SSHException("Invalid username or password")
except Exception as e:
raise SSHException("An exception happened")
def get(self):
"""从会话池中获取 SSH 会话
1. 返回一个存活的会话
2. 不存在的会话或已经失效的会话, 会新建一个会话并返回该会话
"""
conn = super(SSHPool, self).get()
print("get: [%s]" % conn)
if conn:
if conn.get_transport().is_active()