I tried to use the code with a small bash script that is simply writing the strings read from stdin to a log file. The call to the script with writing several lines to it does not return before I press Ctrl-D in the term calling the python scriptlet. Additionally there is no output in the log file.
Here is the test code:
import os
import pwd
import subprocess
from rolekit.functions import writefile
from tempfile import SpooledTemporaryFile
def temporary_stdin(io_input):
    """
    Create a temporary in-memory file object to store input for
    subprocess_future() calls. This is useful for passing passwords
    without specifying them on the command line (which would cause
    them to appear in the process table)
    """
    f = SpooledTemporaryFile()
    f.write(io_input)
    f.seek(0)
writefile("/tmp/readstdin", '#!/bin/bash\nwhile read line\ndo\necho "$line" >> /tmp/readstdin.log\ndone\n')
stdinfile = temporary_stdin("line 1\nline 2\nline 3\n")
preexec_fn = None
args = [ "/bin/bash", "/tmp/readstdin" ]
try:
    process = subprocess.Popen(args, close_fds=True,
                               stdin=stdinfile,
                               stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE,
                               preexec_fn=preexec_fn)
except OSError, e:
    if e.errno is errno.EPERM:
        # Could not change users prior to executing the subprocess
        print("ERROR: Insufficient privileges to impersonate UID/GID %s/%s" %
              (uid, gid))
    raise
print process.stdout.read()

- Thomas Woerner

On January 22nd, 2015, 10 p.m. UTC, Stephen Gallagher wrote:

Add utility routine for passing stdin into subprocesses