mesos-dns-option.py

import traceback
import sys
import json
import argparse
import requests
from requests.api import request
try:
    # For Python 3.0 and later
    from urllib.request import urlopen
except ImportError:
    # Fall back to Python 2's urllib2
    from urllib2 import urlopen

def getIpPortDns(mesosDnsAddr, serviceMesosDns):
    
    '''[
        {
        "service": "_auth-db-auth._tcp.marathon.mesos.",
        "ip": "10.0.0.13",
        "port": "31332"
        }
        ]'''
    response = requests.get(mesosDnsAddr + "/v1/services/" + serviceMesosDns, timeout = 20)
    if response.status_code == requests.codes.ok:
        #print(response.text)
        responseJson = json.loads(response.text)
        ip = responseJson[0]["ip"]
        port = responseJson[0]["port"]
        if not ip:
            print("No ip for " + serviceMesosDns)
        if not port:
            print("No port for " + serviceMesosDns)
    else:
        print("Error getting ip/port for " + serviceMesosDns)
        ip = ""
        port = ""
    return (ip, port)



if __name__ == "__main__":
    print("Running the Mesos DNS ip/port extractor")
    parser = argparse.ArgumentParser(description="Get the ip/port for various services from Mesos DNS")
    parser.add_argument('--mesosdns', required=True, help='Mesos DNS full address e.g. http://127.0.0.1:8123')
    parser.add_argument('--mesosdns_db', required=True, help="Mesos DNS full name for the DB e.g. '_auth-db-auth._tcp.marathon.mesos.'")
    parser.add_argument('--vars', required=True, help="The full path of the file which will be generated by this script. It will contain the new values for various env variables that are needed by the web-app e.g. './config.txt'")
    
    args = parser.parse_args()
    varsFName = args.vars
    mesosDnsAddr = args.mesosdns
    mesosDnsDb = args.mesosdns_db
    
    

with open(varsFName, "w") as varsF:
    ipPort = getIpPortDns(mesosDnsAddr, mesosDnsDb)
    print("AUTH_DB_HOST IP: " + ipPort[0])
    print("AUTH_DB_HOST PORT: " + ipPort[1])
    varsF.write("AUTH_DB_HOST=" + ipPort[0] + "\n")
    varsF.write("AUTH_DB_PORT=" + ipPort[1] + "\n")