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Service module crashes if args has no "=". #250

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Apr 26, 2012
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63 changes: 50 additions & 13 deletions lib/ansible/connection.py
Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,8 @@
import shutil
import subprocess
import pipes
import socket
import random

from ansible import errors
# prevent paramiko warning noise
Expand All @@ -37,6 +39,7 @@

################################################

RANDOM_PROMPT_LEN = 32 # 32 random chars in [a-z] gives > 128 bits of entropy


class Connection(object):
Expand Down Expand Up @@ -142,19 +145,53 @@ def exec_command(self, cmd, tmp_path, sudoable=False): # pylint: disabl
quoted_command = '"$SHELL" -c ' + pipes.quote(cmd)
chan.exec_command(quoted_command)
else:
# Rather than detect if sudo wants a password this time, -k makes
# sudo always ask for a password if one is required. The "--"
# tells sudo that this is the end of sudo options and the command
# follows. Passing a quoted compound command to sudo (or sudo -s)
# directly doesn't work, so we shellquote it with pipes.quote()
# and pass the quoted string to the user's shell.
sudocmd = 'sudo -k -- "$SHELL" -c ' + pipes.quote(cmd)
chan.exec_command(sudocmd)
if self.runner.sudo_pass:
while not chan.recv_ready():
time.sleep(0.25)
sudo_output = chan.recv(bufsize) # Pull prompt, catch errors, eat sudo output
chan.sendall(self.runner.sudo_pass + '\n')
"""
Sudo strategy:

First, if sudo doesn't need a password, it's easy: just run the
command.

If we need a password, we want to read everything up to and
including the prompt before sending the password. This is so sudo
doesn't block sending the prompt, to catch any errors running sudo
itself, and so sudo's output doesn't gunk up the command's output.
Some systems have large login banners and slow networks, so the
prompt isn't guaranteed to be in the first chunk we read. So, we
have to keep reading until we find the password prompt, or timeout
trying.

In order to detect the password prompt, we set it ourselves with
the sudo -p switch. We use a random prompt so that a) it's
exceedingly unlikely anyone's login material contains it and b) you
can't forge it. This can fail if passprompt_override is set in
/etc/sudoers.

Some systems are set to remember your sudo credentials for a set
period across terminals and won't prompt for a password. We use
sudo -k so it always asks for the password every time (if one is
required) to avoid dealing with both cases.

The "--" tells sudo that this is the end of sudo options and the
command follows.

We shell quote the command for safety, and since we can't run a quoted
command directly with sudo (or sudo -s), we actually run the user's
shell and pass the quoted command string to the shell's -c option.
"""
prompt = '[sudo via ansible, key=%s] password: ' % ''.join(chr(random.randint(ord('a'), ord('z'))) for _ in xrange(RANDOM_PROMPT_LEN))
sudocmd = 'sudo -k -p "%s" -- "$SHELL" -c %s' % (prompt, pipes.quote(cmd))
sudo_output = ''
try:
chan.exec_command(sudocmd)
if self.runner.sudo_pass:
while not sudo_output.endswith(prompt):
chunk = chan.recv(bufsize)
if not chunk:
raise errors.AnsibleError('ssh connection closed waiting for sudo password prompt')
sudo_output += chunk
chan.sendall(self.runner.sudo_pass + '\n')
except socket.timeout:
raise errors.AnsibleError('ssh timed out waiting for sudo.\n' + sudo_output)

stdin = chan.makefile('wb', bufsize)
stdout = chan.makefile('rb', bufsize)
Expand Down
9 changes: 6 additions & 3 deletions library/service
Original file line number Diff line number Diff line change
Expand Up @@ -37,9 +37,12 @@ if not len(items):
sys.exit(1)

params = {}
for x in items:
(k, v) = x.split("=")
params[k] = v
for arg in items:
if "=" not in arg:
print json.dumps(dict(failed=True, msg='expected arguments of the form name=value'))
sys.exit(1)
(name, value) = arg.split("=")
params[name] = value

name = params['name']
state = params.get('state','unknown')
Expand Down