breakbuidl/pub-sub

Introduction

The module pubsubservice in this project replicates the Pub/Sub service that facilitates the communication among different microservices. It does so with the help of two packages viz. microservice and pubsub.

• microservice package serves as the client of the pubsub system in form of Subscriber and Publisher.
• pubsub package provides the core functionality of the system with Message, Subscription and Topic as key components.

Setup

1. Download the repository.
2. go build at the root of the directory
3. ./pubsubservice to run the program
4. go test -v ./... to run the tests

Details

The design of the components is such that to keep them as loosely coupled as possible to simulate different services in different containers.

microservice package provides an Ms struct for microservice schema and its methods.

• Ms.Start() starts the service to listen on channel to recieve messages
• Ms.Stop() stops the service and no further messages can be sent

Here's how a typical functioning goes: (Subscriptions and Topics are created beforehand)

• Ms publishes messages to topic
• pubsub broadcasts the message on all the subscribed microservices' msgChannel
• If the subscribed microservice recieves the message, it sends an ack on ackChannel. If pubsub doesn't recieve ack within ackDeadlineSeconds, it tries for msgAttemps number of times. (these configs are set in subscription)