Metropolis (Python Microservice Gateway with NATS)
Can we make
simple
,scalable
,observable
,operable
service gateway?
Purpose
Cloud Native
Single Workload Unit
Service Discovery
Service Mesh
Architecture Concept
+- Cluster --------------------------------------------------+
| |
| +- Node-1 --+ +- Node-2 -+ +- Node-3 --+ +- Node-4 -+ |
| | | | | | | | | |
| | Worker-a | | | | | | Worker-d | |
| | Worker-b | | Worker-c | | Worker-a | | Worker-c | |
| | | | | | | | | | | | | |
<======= NATS ========= NATS ======================= NATS =======>
| | | | | | | | | | | |
| | Gateway | | | | Gateway | | | |
| | | | | | | | | | | |
| +--- | -----+ +----------+ +--- | -----+ +----------+ |
| | | |
| +--------------+-------------+ |
| | |
| Ingress |
+--------------------- | ------------------------------------+
V
Components
Nats
Message bus
Worker
Business Logic worker
Gateway
Service gateway
Example
Install metropolis
$ pip install metropolis
Define Worker task
from metropolis import Worker
worker = Worker(nats='nats://localhost:4222')
@worker.task(subject='foo.bar', queue='worker')
def mytask(data, *args, **kwargs):
"""Simple task which returns reverse string
"""
return data[0][::-1]
worker.run()
Define Gateway
from metropolis import Gateway
import settings
gateway = Gateway(nats='nats://nats:4222')
gateway.app.run(host='0.0.0.0')