我的标准程序PostgreSQL用于访问远程服务器上的数据库是打开的，首先创建一个ssh隧道：
ssh username1@remote.somewhere.com -L 5432:localhost:5432 -p 222
然后在python中从另一个shell运行我的查询：
conn = psycopg2.connect("host=localhost" + " dbname=" +
conf.dbname + " user=" + conf.user +
" password=" + conf.password)
cur = conn.cursor()
cur.execute(query)
创建隧道后，这段python代码可以很好地工作。但是，我希望psycopg2已经打开SSH隧道或“以某种方式”到达远程数据库而无需在我的localhost上重定向它。
是否可以使用psycopg2执行此操作？
否则可以在我的python代码中打开ssh隧道？
如果我使用：
os.system("ssh username1@remote.somewhere.com -L 5432:localhost:5432 -p 222")
shell将被重定向到远程主机，阻止主线程的执行。
答案 0 :(得分：7)
你也可以使用sshtunnel，短而甜：
from sshtunnel.sshtunnel import SSHTunnelForwarder
PORT=5432
with SSHTunnelForwarder((REMOTE_HOST, REMOTE_SSH_PORT),
ssh_username=REMOTE_USERNAME,
ssh_password=REMOTE_PASSWORD,
remote_bind_address=('localhost', PORT),
local_bind_address=('localhost', PORT)):
conn = psycopg2.connect(...)
答案 1 :(得分：1)
通过os.system在单独的线程/进程中调用您的ssh。您还可以将-N与ssh一起使用以避免打开远程shell。
答案 2 :(得分：0)
Clodoaldo Neto的代码完美地为我工作，但要注意它之后不会清理这个过程。
Luca Fiaschi所展示的方法也适用于我。我为python3和更新的psutil模块更新了一下。更改只是process.username和process.cmdline现在是函数，迭代器是process_iter（）而不是get_process_list（）。
这是一个稍微修改过的代码示例，Luca Fiaschi发布了与python3一起使用的代码（需要psutil模块）。我希望它至少大部分是正确的！
#!/usr/bin/env python3
import psutil
import psycopg2
import subprocess
import time
import os
# Tunnel Config
SSH_HOST = "111.222.333.444"
SSH_USER = "user"
SSH_KEYFILE = "key.pem"
SSH_FOREIGN_PORT = 5432 # Port that postgres is running on the foreign server
SSH_INTERNAL_PORT = 5432 # Port we open locally that is forwarded to
# FOREIGN_PORT on the server.
# Postgres Config
DB_HOST = "127.0.0.1"
DB_PORT = SSH_INTERNAL_PORT
DB_PASSWORD = "password"
DB_DATABASE = "postgres"
DB_USER = "user"
class SSHTunnel(object):
"""
A context manager implementation of an ssh tunnel opened from python
"""
def __init__(self, tunnel_command):
assert "-fN" in tunnel_command, "need to open the tunnel with -fN"
self._tunnel_command = tunnel_command
self._delay = 0.1
self.ssh_tunnel = None
def create_tunnel(self):
tunnel_cmd = self._tunnel_command
ssh_process = subprocess.Popen(tunnel_cmd, universal_newlines=True,
shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
stdin=subprocess.PIPE)
# Assuming that the tunnel command has "-f" and "ExitOnForwardFailure=yes", then the
# command will return immediately so we can check the return status with a poll().
while True:
p = ssh_process.poll()
if p is not None: break
time.sleep(self._delay)
if p == 0:
# Unfortunately there is no direct way to get the pid of the spawned ssh process, so we'll find it
# by finding a matching process using psutil.
current_username = psutil.Process(os.getpid()).username()
ssh_processes = [proc for proc in psutil.process_iter() if proc.cmdline() == tunnel_cmd.split() and proc.username() == current_username]
if len(ssh_processes) == 1:
self.ssh_tunnel = ssh_processes[0]
return ssh_processes[0]
else:
raise RuntimeError('multiple (or zero?) tunnel ssh processes found: ' + str(ssh_processes))
else:
raise RuntimeError('Error creating tunnel: ' + str(p) + ' :: ' + str(ssh_process.stdout.readlines()))
def release(self):
""" Get rid of the tunnel by killin the pid
"""
if self.ssh_tunnel:
self.ssh_tunnel.terminate()
def __enter__(self):
self.create_tunnel()
return self
def __exit__(self, type, value, traceback):
self.release()
def __del__(self):
self.release()
command = "ssh -i %s %s@%s -fNL %d:localhost:%d"\
% (SSH_KEYFILE, SSH_USER, SSH_HOST, SSH_INTERNAL_PORT, SSH_FOREIGN_PORT)
with SSHTunnel(command):
conn = psycopg2.connect(host = DB_HOST, password = DB_PASSWORD,
database = DB_DATABASE, user = DB_USER, port = DB_PORT)
curs = conn.cursor()
sql = "select * from table"
curs.execute(sql)
rows = curs.fetchall()
print(rows)
答案 3 :(得分：0)
使用 sshtunnel 包
我不熟悉 SSH 隧道，所以我在使用 mrts 的回答时遇到了一些困难。 也许这些精确度可以帮助某人。
在 psycopg2.connect() 中，host 和 port 是您刚刚通过 ssh 隧道连接远程主机创建的。
这是我的代码：
from sshtunnel import SSHTunnelForwarder
server = SSHTunnelForwarder((REMOTE_HOST, REMOTE_SSH_PORT),
ssh_username=REMOTE_USERNAME,
ssh_password=REMOTE_PASSWORD,
remote_bind_address=('localhost', PORT),
local_bind_address=('localhost', PORT))
server.start()
import psycopg2
conn = psycopg2.connect(
database=DATABASE,
user=USER,
host=server.local_bind_host,
port=server.local_bind_port,
password=PWD)
cur = conn.cursor()
cur.execute("select * from yourtable limit 1;")
data = cur.fetchall()
print(data)
我希望这个例子更清楚。
答案 4 :(得分：-1)
目前我正在使用基于this gist的解决方案：
class SSHTunnel(object):
"""
A context manager implementation of an ssh tunnel opened from python
"""
def __init__(self, tunnel_command):
assert "-fN" in tunnel_command, "need to open the tunnel with -fN"
self._tunnel_command = tunnel_command
self._delay = 0.1
def create_tunnel(self):
tunnel_cmd = self._tunnel_command
import time, psutil, subprocess
ssh_process = subprocess.Popen(tunnel_cmd, universal_newlines=True,
shell=True,
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
stdin=subprocess.PIPE)
# Assuming that the tunnel command has "-f" and "ExitOnForwardFailure=yes", then the
# command will return immediately so we can check the return status with a poll().
while True:
p = ssh_process.poll()
if p is not None: break
time.sleep(self._delay)
if p == 0:
# Unfortunately there is no direct way to get the pid of the spawned ssh process, so we'll find it
# by finding a matching process using psutil.
current_username = psutil.Process(os.getpid()).username
ssh_processes = [proc for proc in psutil.get_process_list() if proc.cmdline == tunnel_cmd.split() and proc.username == current_username]
if len(ssh_processes) == 1:
self.ssh_tunnel = ssh_processes[0]
return ssh_processes[0]
else:
raise RuntimeError, 'multiple (or zero?) tunnel ssh processes found: ' + str(ssh_processes)
else:
raise RuntimeError, 'Error creating tunnel: ' + str(p) + ' :: ' + str(ssh_process.stdout.readlines())
def release(self):
""" Get rid of the tunnel by killin the pid
"""
self.ssh_tunnel.terminate()
def __enter__(self):
self.create_tunnel()
return self
def __exit__(self, type, value, traceback):
self.release()
def __del__(self):
self.release()
def test():
#do things that will fail if the tunnel is not opened
print "done =========="
command = "ssh username@someserver.com -L %d:localhost:%d -p 222 -fN" % (someport, someport)
with SSHTunnel(command):
test()
如果有人有更好的主意，请告诉我
答案 5 :(得分：-2)
from time import sleep
os.system("ssh username1@remote.somewhere.com -fNL 5432:localhost:5432 -p 222")
while True:
try:
conn = psycopg2.connect(
"host=localhost dbname={0} user={1} password={2}".format(
conf.dbname, conf.user, conf.password
)
)
break
except psycopg2.OperationalError:
sleep(3)