forever.sh

while true
do
  ./test.py >> log.txt
done

test.py

#!/usr/bin/python3
import requests
import datetime
import time
import sys

from google.cloud import bigquery

ZONE = "us-central1-a"

ENDPOINTS = [
    "http://snap-tests-217018.appspot.com/hello",
    "http://snap-tests-217018.appspot.com/file",
]

BQ = bigquery.Client()
TABLE_REF = BQ.dataset("latency").table("measures")
TABLE = BQ.get_table(TABLE_REF)  # API request

def load_test(endpoint):
    """Times latency to hit endpoint & logs into BQ."""
    response = requests.get(endpoint)
    rows = [(
        ZONE,
        datetime.datetime.utcnow().isoformat(), 
        response.elapsed.total_seconds(),
        endpoint)]
    errors = BQ.insert_rows(TABLE, rows)
    if len(errors) != 0: 
        print(errors, file=sys.stderr)
    else:
        print("probe: %s - %s - %f - %s" % (rows[0][0], rows[0][1], rows[0][2], rows[0][3]))
        
def main():
    while True:
        for endpoint in ENDPOINTS:
            load_test(endpoint)
            sys.stdout.flush()
            sys.stderr.flush()
            time.sleep(1)
    
if __name__ == "__main__":
    main()

VM Script

sudo apt-get update \
&& sudo apt-get upgrade -y \
&& sudo apt-get dist-upgrade \
&& sudo apt-get install python3-pip -y \
&& pip3 install google-cloud-bigquery \
&& wget https://gist.githubusercontent.com/cobookman/424670df4c1dca6e5c75a8df7b62e760/raw/eba0bfec3871089446ce6f31efbf066b83ed150f/forever.sh \
&& wget https://gist.githubusercontent.com/cobookman/424670df4c1dca6e5c75a8df7b62e760/raw/eba0bfec3871089446ce6f31efbf066b83ed150f/test.py \
&& chmod +x * \
&& sudo reboot -n