primitive_ad_hoc_http_pinger.py

import subprocess
import time
import sys


interval = 2.0

while True:
	t1 = time.time()
	#http://manpages.ubuntu.com/manpages/trusty/en/man1/curl.1.html
	#http://stackoverflow.com/questions/17638026/calculating-server-processing-time-with-curl/29650456#29650456
	#https://curl.haxx.se/mail/lib-2011-05/0026.html
	subprocess.call("date -u --rfc-3339=seconds | tr -d '\\n'; echo -n '  '; curl --write-out 'st=%{http_code} sz=%{size_download} ip=%{remote_ip}"
		" ns^%{time_namelookup} conn^%{time_connect} sent^%{time_pretransfer} firstbyte^%{time_starttransfer} tot=%{time_total}\\n'"
		" --silent --show-error --compressed -o /dev/null https://localhost/", shell = True)
	sys.stdout.flush()
	lat = time.time() - t1

	time.sleep(max(0, interval - lat))