Kubernetes环境下pysftp.Connection报OSError: Int or String expected求助

环境信息 #

• Python 3.7.6
• pysftp 0.2.9
• paramiko 3.0.0
• 操作系统：Ubuntu 20.04 LTS (Focal Fossa)
• 运行环境：IBM Elyra + Kubernetes 上的Jupyter Notebook

报错详情 #

---------------------------------------------------------------------------
OSError                                   Traceback (most recent call last)
/usr/local/bin/kernel-launchers/python/scripts/launch_ipykernel.py in <module>
----> 1 sftp_conn = pysftp.Connection(host=sftp_info['host'],port= sftp_info['port'], username= sftp_info['login'], password=sftp_info['password'],cnopts=cnopts)

/opt/conda/lib/python3.7/site-packages/pysftp/__init__.py in __init__(self, host, username, private_key, password, port, private_key_pass, ciphers, log, cnopts, default_path)
    138         # Begin the SSH transport.
    139         self._transport = None
--> 140         self._start_transport(host, port)
    141         self._transport.use_compression(self._cnopts.compression)
    142         self._set_authentication(password, private_key, private_key_pass)

/opt/conda/lib/python3.7/site-packages/pysftp/__init__.py in _start_transport(self, host, port)
    174         '''start the transport and set the ciphers if specified.'''
    175         try:
--> 176             self._transport = paramiko.Transport((host, port))
    177             # Set security ciphers if set
    178             if self._cnopts.ciphers is not None:

/opt/conda/lib/python3.7/site-packages/paramiko/transport.py in __init__(self, sock, default_window_size, default_max_packet_size, gss_kex, gss_deleg_creds, disabled_algorithms, server_sig_algs)
    428             reason = "No suitable address family"
    429             addrinfos = socket.getaddrinfo(
--> 430                 hostname, port, socket.AF_UNSPEC, socket.SOCK_STREAM
    431             )
    432             for family, socktype, proto, canonname, sockaddr in addrinfos:

/opt/conda/lib/python3.7/socket.py in getaddrinfo(host, port, family, type, proto, flags)
    750     # and socket type values to enum constants.
    751     addrlist = []
--> 752     for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
    753         af, socktype, proto, canonname, sa = res
    754         addrlist.append((_intenum_converter(af, AddressFamily),

OSError: Int or String expected

实现代码 #

import pysftp

cnopts = pysftp.CnOpts(knownhosts=None)
# cnopts.hostkeys = None
key = pysftp.RSAKey(data=decodebytes(keydata))


cnopts.hostkeys.add(sftp_info["host"], "ssh-rsa", key)

sfc = pysftp.Connection(
    host=sftp_info["host"],
    port=sftp_info["port"],
    username=sftp_info["login"],
    password=sftp_info["password"],
    cnopts=cnopts,
)

sfc.listdir()

额外警告 #

/opt/conda/lib/python3.7/site-packages/pysftp/__init__.py:61: UserWarning: Failed to load HostKeys from /home/jovyan/.ssh/known_hosts.  You will need to explicitly load HostKeys (cnopts.hostkeys.load(filename)) or disableHostKey checking (cnopts.hostkeys = None).
  warnings.warn(wmsg, UserWarning)

本地测试对比 #

本地Docker环境（基于Python:3.7.6镜像，Debian 10 (buster)）复刻相同依赖版本，代码可正常运行，即使删除~/.ssh/known_hosts也能成功连接并返回目录列表：

>>> sfc.listdir()
['data', 'fire']

直接使用paramiko连接也出现完全相同的错误，目前无法定位问题。

排查方向与解决方案 #

1. 检查sftp_info中port字段的类型
   错误提示"Int or String expected"，大概率是port参数类型异常。Kubernetes环境中，配置值可能被解析为非字符串/整数类型（比如None、布尔值或者其他对象）。在创建连接前强制转换port类型：

   # 确保port是整数或字符串
   port = int(sftp_info["port"]) if isinstance(sftp_info["port"], str) else sftp_info["port"]
   sfc = pysftp.Connection(
       host=sftp_info["host"],
       port=port,
       username=sftp_info["login"],
       password=sftp_info["password"],
       cnopts=cnopts,
   )
   

2. 验证sftp_info中host字段的有效性
   确认sftp_info["host"]是合法的字符串格式（域名或IP），没有出现空值、None或者特殊字符。可以在代码中添加打印：

   print(f"Host: {sftp_info['host']}, Type: {type(sftp_info['host'])}")
   print(f"Port: {sftp_info['port']}, Type: {type(sftp_info['port'])}")
   

3. 降级paramiko版本
   pysftp 0.2.9是比较旧的版本，而paramiko 3.0.0有较大的API变更，两者兼容性可能存在问题。尝试降级paramiko到2.x版本：

   pip install paramiko==2.12.0
   

4. 检查Kubernetes环境的DNS解析
   虽然错误提示是参数类型，但也有可能是K8s环境中DNS解析异常导致host字段处理出错。可以在Notebook中执行ping命令验证SFTP服务器的可达性：

   import subprocess
   subprocess.run(["ping", "-c", "3", sftp_info["host"]])
   

内容的提问来源于stack exchange，提问作者arundeep78