email_client.py

#!/usr/bin/python
#
# Copyright 2018 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import grpc
import os

import demo_pb2
import demo_pb2_grpc

from opencensus.trace.tracer import Tracer
from opencensus.ext.grpc import client_interceptor
from opencensus.ext.zipkin.trace_exporter import ZipkinExporter
from opencensus.trace.samplers import AlwaysOnSampler

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

# Setup Zipkin exporter
try: 
  zipkin_service_addr = os.environ.get("ZIPKIN_SERVICE_ADDR", '')
  if zipkin_service_addr == "":
    logger.info("Skipping Zipkin traces initialization. Set environment variable ZIPKIN_SERVICE_ADDR=<host>:<port> to enable.")
    raise KeyError()
  host, port = zipkin_service_addr.split(":")
  ze = ZipkinExporter(service_name="recommendationservice-client",
    host_name=host,
    port=port,
    endpoint='/api/v2/spans')
  sampler = AlwaysOnSampler()
  tracer = Tracer(exporter=ze, sampler=sampler)
  tracer_interceptor = client_interceptor.OpenCensusClientInterceptor(sampler, ze)
  logger.info("Zipkin traces enabled, sending to " + zipkin_service_addr)
except KeyError:
  tracer_interceptor = client_interceptor.OpenCensusClientInterceptor()

def send_confirmation_email(email, order):
  channel = grpc.insecure_channel('0.0.0.0:8080')
  channel = grpc.intercept_channel(channel, tracer_interceptor)
  stub = demo_pb2_grpc.EmailServiceStub(channel)
  try:
    response = stub.SendOrderConfirmation(demo_pb2.SendOrderConfirmationRequest(
      email = email,
      order = order
    ))
    logger.info('Request sent.')
  except grpc.RpcError as err:
    logger.error(err.details())
    logger.error('{}, {}'.format(err.code().name, err.code().value))

if __name__ == '__main__':
  logger.info('Client for email service.')