如何使用 python 从 microservice-1 调用 microservice-2？

Question

How to call my microservice-2 from microservice-1. So our result looks like this:-

Result:- {“message”: “vivek”} --> {“message”: “keviv”, “random”: 3.89}

command to access microservice-1:-

curl http://127.0.0.1:5000/reverse_random/vivek

microservice-1

from flask import Flask, jsonify
app = Flask(__name__)

@app.route('/reverse_reandom/<string:string>', methods=['GET'])
def reverse(string):
    string = string[::-1]
    return jsonify({'message': string })


if __name__ == '__main__':
   app.run(debug = True)

microservice-2

import random
from flask import Flask, jsonify

app = Flask(__name__)


@app.route('/', methods=['GET'])
def myRandom():
    r1 = random.uniform(0, 10)
    return jsonify({'message': r1 })

if __name__ == '__main__':
    app.run(debug=True)

Answer 1

you'll need to issue a GET request to service 2 in order to get the random number, I suggest to use requests for this, like

r = requests.get('url-for-service-2:port/')
data = r.json()
random_num = data['message']

keep in mind to check the data object for message key, or using .get() or equivalent

Answer 2

Run microservice-2 on a different port. Send request using Python standard or 3rd party library from microservice-1 to microservice-2 upon request to microservice-1.

Below is the example of using Python3 standard library only:

m1.py:

from flask import Flask, jsonify
import urllib
import json 

app = Flask(__name__)

@app.route('/reverse_random/<string:string>', methods=['GET'])
def reverse(string):
    content = urllib.request.urlopen('http://127.0.0.1:5001').read().decode('utf-8')
    print('response from m2: ', content)
    string = string[::-1]
    return jsonify({'message': string, 'random' : json.loads(content)['message']})


if __name__ == '__main__':
   app.run(debug = True)

m2.py :

import random
from flask import Flask, jsonify

app = Flask(__name__)

@app.route('/', methods=['GET'])
def myRandom():
    r1 = random.uniform(0, 10)

    return jsonify({'message': r1 })

if __name__ == '__main__':
    app.run(debug=True, port=5001) # running m2 on a different port than default 5000

Run the m1: python3 m1.py

Run the m2 in a different shell: python3 m2.py

Send request to m1: curl http://127.0.0.1:5000/reverse_random/vivek

The result is:

{ 
  "message": "keviv",  
  "random": 4.138115905045612 
} 

Observe the log of m1 and of m2 to make sure m2 was invoked.

Answer 3

To connect between services you can use background tasks such as celery and ramq or use nsq and nats