Python通过套接字传递子进程的I/O
我知道网上有类似的问题,但我在这个具体的例子上遇到了麻烦,找不到好的答案。我想为dar设置一个远程备份服务器,大概是这个意思。我之前问过一个单独的问题,关于如何通过调用netcat和subprocess.Popen来实现,但如果可以的话,我更希望用Python来设置套接字并处理所有的数据传输。因为要传输的数据量很大,所以我不能先把所有输入都读完再传递。
现在的问题是,服务器似乎没有读取到数据。
目前,我有以下代码:
from socket import socket, AF_INET, SOCK_STREAM
import sys
import SocketServer
import subprocess
class DarHandler(SocketServer.BaseRequestHandler):
def handle(self):
print('entering handler')
data = self.request.recv(1024).strip()
print('got: ' + data)
if data == 'xform':
s = socket(AF_INET, SOCK_STREAM)
s.bind(('',0))
myaddr, myport = s.getsockname()
print('bound new socket to {0}:{1}'.format(myaddr, myport))
self.request.send(str(myport))
s.listen(1)
conn, remoteaddr = s.accept()
print('accepted connection from {0}:{1}'.format(*remoteaddr))
xform_input = conn.makefile('rb',0)
proc = subprocess.Popen(
['/usr/bin/dar_xform', '-s', '10k', '-', 'archives/sockbackup',],
stdin=xform_input
)
return_code = proc.wait()
print('dar_xform returned {0}'.format(return_code))
conn.close()
self.request.send(str(return_code))
else:
self.request.send('bad request')
print('send result, exiting handler')
server_address = ('localhost', 18010)
def server():
server = SocketServer.TCPServer(server_address, DarHandler)
print('listening')
server.serve_forever()
def client():
sock = socket(AF_INET, SOCK_STREAM)
print('connecting to server')
sock.connect(('localhost', 18010))
print('connected, sending request')
sock.send('xform')
print('waiting for response')
port = sock.recv(1024)
print('got: ' + port)
s = socket(AF_INET, SOCK_STREAM)
s.connect(('localhost', int(port)))
print('connected to dar_xform port')
dar_output = s.makefile('wb',0)
return_code = subprocess.call(
['/usr/bin/dar', '-B', 'config/test.dcf', '-c', '-',],
stdout=dar_output
)
print('dar returned {0}'.format(return_code))
s.close()
result = sock.recv(1024)
print('received: ' + result)
sock.close()
print('socket closed, exiting')
if __name__ == "__main__":
if sys.argv[1].startswith('serv'):
server()
else:
client()
当我在客户端运行时,服务器端输出如下:
listening entering handler got: xform bound new socket to 0.0.0.0:41658 accepted connection from 127.0.0.1:42440
然后就停在那里了。与此同时,dar
在客户端运行,而客户端则一直在等待服务器的响应:
connecting to server connected, sending request waiting for response got: 41300 connected to dar_xform port -------------------------------------------- 53 inode(s) saved with 0 hard link(s) recorded 0 inode(s) changed at the moment of the backup 0 inode(s) not saved (no inode/file change) 0 inode(s) failed to save (filesystem error) 1 inode(s) ignored (excluded by filters) 0 inode(s) recorded as deleted from reference backup -------------------------------------------- Total number of inodes considered: 54 -------------------------------------------- EA saved for 0 inode(s) -------------------------------------------- dar returned 0
1 个回答
0
看起来服务器上的 dar_xform 命令出问题了...
试着给 dar_xform
命令提供一个完整的路径,然后用 subprocess.Popen(...)
来运行,看看问题是否还会出现。你描述的情况很像是 PATH
的问题,特别是因为在命令行里它能正常工作。