@superbalist/js-pubsub-http

An HTTP adapter for the js-pubsub package.

This adapter assumes that you have a HTTP service which accepts an array of messages POSTed to a /messages/(channel) end-point.

A server-side implementation, js-pubsub-rest-proxy, is available as a plug and play Docker appliance.

Installation

npm install @superbalist/js-pubsub-http

Usage

'use strict';

let pubsub = require('@google-cloud/pubsub');
let GoogleCloudPubSubAdapter = require('@superbalist/js-pubsub-google-cloud');
let HTTPPubSubAdapter = require('@superbalist/js-pubsub-http');

process.env.GOOGLE_APPLICATION_CREDENTIALS = '/path/to/your-gcloud-key.json';

// create the underlying adapter which is going to be decorated
let client = pubsub({
  projectId: 'your-project-id-here',
});

let googleCloudAdapter = new GoogleCloudPubSubAdapter(client);

// now create our decorator
// the decorator will proxy subscribe calls straight to the googleCloudAdapter
// publish calls will be POSTed to the service uri
let adapter = new HTTPPubSubAdapter('http://127.0.0.1', googleCloudAdapter);

adapter.subscribe('my_channel', (message) => {
  console.log(message);
  console.log(typeof message);
});

// consume messages
// note: this is a blocking call
adapter.subscribe('my_channel', (message) => {
  console.log(message);
  console.log(typeof message);
});

// publish messages
adapter.publish('my_channel', {first_name: 'Matthew'});
adapter.publish('my_channel', 'Hello World');

// publish multiple messages
let messages = [
  'message 1',
  'message 2',
];
adapter.publishBatch('my_channel', messages);

TODO

• Add unit tests

Examples

The library comes with examples for the adapter and a Dockerfile for running the example scripts.

Run make up.

You will start at a bash prompt in the /usr/src/app directory.

If you need another shell to publish a message to a blocking consumer, you can run docker-compose run js-pubsub-http /bin/bash

To run the examples:

$ ./run_consumer.sh
$ ./run_publisher.sh (in a separate shell)