azure_sudo_timeout.py

#!/usr/bin/python

# Invoke n instances of sudo in parallel. This works fine in all machines I've
# tried this on, except Windows Azure VMs, where occasionally invocations to
# sudo take ~5s to complete when n > 1.
# Tested on a Standard_A1 instance w/Ubuntu Utopic, kernel 3.16.0-34-generic.

import subprocess
import sys
import time

sudo_args = ['/usr/bin/sudo', '/bin/true']

def run(n):
	t0 = time.time()
	processes = [subprocess.Popen(sudo_args) for i in xrange(n)]
	pids = [p.pid for p in processes]
	assert(all([p.wait() == 0 for p in processes]))
	t1 = time.time()
	delta = (t1 - t0) * 1000
	if delta >= 1000:
		print '%.2f %.2f %.2f %r' % (t0, t1, delta, pids)

if __name__ == '__main__':
	try:
		n = int(sys.argv[1])
	except:
		sys.stderr.write('Usage: python %s <processes>\n' % sys.argv[0])
		sys.exit(1)
	while True:
		run(n)