ldej / microservice-example

Microservice example

A nats, asyncio, aiohttp, sqlalchemy example for creating a microservice.

Installation

git clone https://github.com/ldej/microservice-example
cd ./microservice-example
docker-compose build

Basic usage

Start the project

docker-compose up

Make a call to create a thing:

curl -X POST 'http://127.0.0.1:5000/thing_service.create_thing' -d '{"name": "Alice"}'

See that a thing is created:

curl -X POST 'http://127.0.0.1:5000/thing_service.get_things'

Try the basic greeting service:

curl -X POST 'http://127.0.0.1:5000/greeting_service.hello' -d '{"name": "Bob"}'

See the asyncio in action. The greeting_service.hello_sleep call will sleep for 10 seconds. So open two terminals, in the first one:

curl -X POST 'http://127.0.0.1:5000/greeting_service.hello_sleep' -d '{"name": "Sleepy Bob"}'

And in the second:

curl -X POST 'http://127.0.0.1:5000/greeting_service.hello' -d '{"name": "Awake Bob"}'

The second call should return before the first call.

Websockets

Make sure the project is started. Open frontend/index.html. In the subscribe section, the RPC input will be filled with websocket_test.websocket_test. When pressing send, the websocket will be subscribed to that message on nats. There are two ways to confirm that it works. The first is to do:

curl -X POST 'http://127.0.0.1:5000/websocket_test.hello_websocket' -d '{"websockets": "are awesome"}'

This is a normal HTTP POST call. The call websocket_test.hello_websocket will send a message over nats on channel websocket_test.websocket_test. The browser will then show the message that was sent.

The second way to confirm is by using the publish section of the frontend. This will send the message to the backend over the websocket (instead of HTTP POST). And it should give the same result in the frontend.