A sample repo to demonstrate a microservice based Nodejs/Express architecture in the form of a basic user service and a basic cat service with a provided frontend to allow a user to "like" a cat.
Inter-service communication is performed across two channels:
- Direct communication between services is done via REST endpoints exposed by the service itself
- Indirect communication is done via PUBSUB channels on a Redis server using a shared Publisher/Subscriber client in the
commspackage
An example of direct communication in this repository would be populating the list of "liked" cats for a particular user as demonstrated in the /user/:id/cats endpoint. An example of indirect communication is updating the number of likes a cat has received on the liked_cat channel. The actual implementation of this in the lib/users.js and lib/cats.js in each respective package. Indirect communication is completely event driven in the case that an action affects multiple services and not just a single one.
The number of microservices that can be implemented on this structure is only limited by the number of ports available to use. An improvement to this system would be to dockerize the entire system and implement a form of service discovery to allow ports to be easily configured.
To get started simply pull the repo and run:
lerna bootstrap
npm run start
This will start each service independently, including the basic web page to interact with the services. A Redis server is required. The default ports are:
- Users:
:8001 - Cats:
:8002 - Frontend:
:3000