2 Connect to a remote host via SSH and execute a command on the host.
9 from bup import helpers
12 def connect(rhost, port, subcmd):
13 """Connect to 'rhost' and execute the bup subcommand 'subcmd' on it."""
14 assert(not re.search(r'[^\w-]', subcmd))
15 main_exe = os.environ.get('BUP_MAIN_EXE') or sys.argv[0]
16 nicedir = os.path.split(os.path.abspath(main_exe))[0]
17 nicedir = re.sub(r':', "_", nicedir)
21 argv = ['bup', subcmd]
23 # WARNING: shell quoting security holes are possible here, so we
24 # have to be super careful. We have to use 'sh -c' because
25 # csh-derived shells can't handle PATH= notation. We can't
26 # set PATH in advance, because ssh probably replaces it. We
27 # can't exec *safely* using argv, because *both* ssh and 'sh -c'
28 # allow shellquoting. So we end up having to double-shellquote
30 escapedir = re.sub(r'([^\w/])', r'\\\\\\\1', nicedir)
31 buglvl = helpers.atoi(os.environ.get('BUP_DEBUG'))
32 force_tty = helpers.atoi(os.environ.get('BUP_FORCE_TTY'))
34 sh -c PATH=%s:'$PATH BUP_DEBUG=%s BUP_FORCE_TTY=%s bup %s'
35 """ % (escapedir, buglvl, force_tty, subcmd)
38 argv.extend(('-p', port))
39 argv.extend((rhost, '--', cmd.strip()))
40 #helpers.log('argv is: %r\n' % argv)
42 # runs in the child process
44 os.environ['PATH'] = ':'.join([nicedir,
45 os.environ.get('PATH', '')])
47 return subprocess.Popen(argv, stdin=subprocess.PIPE, stdout=subprocess.PIPE,