I'm writing a python script to automatize the installation of some tools every time I create a VM and, since I'm not a bash fan I'm doing it with python.
The problem is that apt
installations require sudo privileges, while pip
installations don't.
I'm looking for a way to downgrade my privileges back to normal user's after all apt installations.
At the moment I tryed a pretty ugly oneliner like os.system(f"su {user} && ...")
or subprocess.Popen(...)
Is there a decent way?
CodePudding user response:
You can use a list of apt
commands with subprocess
or pexpect
. It can also prompt for a password if no password is provided using getpass
:
NOTE - Tested on Ubuntu 20.04 using Python 3.8.10
NOTE - Updated to use and test pipes.quote - Thx, pts!
import pipes
import shlex
import subprocess
from getpass import getpass
import pexpect
sudo_password = '********'
# First command in double quotes to test pipes.quote - Thx, pts!
commands = ["apt show python3 | grep 'Version'",
'sudo -S apt show python3 | grep Version', ]
print('Using subprocess...')
for c in commands:
c = str.format('bash -c {0}'.format(pipes.quote(c)))
# Use sudo_password if not None or empty; else, prompt for a password
sudo_password = (
sudo_password '\r'
) if sudo_password and sudo_password.strip() else getpass() '\r'
p = subprocess.Popen(shlex.split(c), stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE, universal_newlines=True)
output, error = p.communicate(sudo_password)
rc = p.returncode
if rc != 0:
raise RuntimeError('Unable to execute command {0}: {1}'.format(
c, error.strip()))
else:
print(output.strip())
print('\nUsing pexpect...')
for c in commands:
c = str.format('bash -c {0}'.format(pipes.quote(c)))
command_output, exitstatus = pexpect.run(
c,
# Use sudo_password if not None or empty; else, prompt for a password
events={
'(?i)password': (
sudo_password '\r'
) if sudo_password and sudo_password.strip() else (
getpass() '\r')
},
withexitstatus=True)
if exitstatus != 0:
raise RuntimeError('Unable to execute command {0}: {1}'.format(
c, command_output))
# For Python 2.x, use string_escape.
# For Python 3.x, use unicode_escape.
# Do not use utf-8; Some characters, such as backticks, may cause exceptions
print(command_output.decode('unicode_escape').strip())
Output:
Using subprocess...
Version: 3.8.2-0ubuntu2
Version: 3.8.2-0ubuntu2
Using pexpect (and getpass)...
Version: 3.8.2-0ubuntu2
[sudo] password for stack:
Version: 3.8.2-0ubuntu2
Process finished with exit code 0