email_server.py

#!/usr/bin/python

from concurrent import futures
import argparse
import os
import sys
import time
import grpc
from jinja2 import Environment, FileSystemLoader, select_autoescape, TemplateError

import demo_pb2
import demo_pb2_grpc
from grpc_health.v1 import health_pb2
from grpc_health.v1 import health_pb2_grpc

from logger import getJSONLogger
logger = getJSONLogger('emailservice-server')

# Loads confirmation email template from file
env = Environment(
    loader=FileSystemLoader('templates'),
    autoescape=select_autoescape(['html', 'xml'])
)
template = env.get_template('confirmation.html')

class BaseEmailService(demo_pb2_grpc.EmailServiceServicer):
  def Check(self, request, context):
    return health_pb2.HealthCheckResponse(
      status=health_pb2.HealthCheckResponse.SERVING)

class DummyEmailService(BaseEmailService):
  def SendOrderConfirmation(self, request, context):
    logger.info('A request to send order confirmation email to {} has been received.'.format(request.email))
    return demo_pb2.Empty()

class HealthCheck():
  def Check(self, request, context):
    return health_pb2.HealthCheckResponse(
      status=health_pb2.HealthCheckResponse.SERVING)

def start(dummy_mode):
  server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
  service = None
  if dummy_mode:
    service = DummyEmailService()
  else:
    raise Exception('non-dummy mode not implemented yet')

  demo_pb2_grpc.add_EmailServiceServicer_to_server(service, server)
  health_pb2_grpc.add_HealthServicer_to_server(service, server)

  port = os.environ.get('PORT', "8080")
  logger.info("listening on port: "+port)
  server.add_insecure_port('[::]:'+port)
  server.start()
  try:
    while True:
      time.sleep(3600)
  except KeyboardInterrupt:
    server.stop(0)




if __name__ == '__main__':
  logger.info('starting the email service in dummy mode.')
  start(dummy_mode = True)