@sagi.io/workers-pubsub

workers-pubsub

@sagi.io/workers-pubsub is a Google Pub/Sub REST API for Cloudflare Workers (can also be used with Node).

⭐ We use it at OpenSay to efficiently access Google's PubSub REST API with 1 round trip.

Installation

$ npm i @sagi.io/workers-pubsub

API

We follow Google's Pub/Sub REST API specification. We'll add more methods if there's demand.

See below for concrete examples for Cloudflare Workers and Node.js.

PubSubREST({ ... })

Instantiates PubSub instance.

Function definition:

 const PubSubREST = async ({
  serviceAccountJSON,
  cryptoImpl = null,
  fetchImpl = null,
}) => { ... }

Where:

• serviceAccountJSON required Is a Google Cloud service account with a Pub/Sub Admin role. An object.
• cryptoImpl optional Not needed when running on Cloudflare Workers. See concrete example below for how to use it with Node.js.
• fetchImpl optional Not needed when running on Cloudflare Workers. See concrete example below for how to use it with Node.js.

PubSub.topics.publish({ ... })

Publishes a message to a topic.

Function definition:

const publish = ({ topic, messages } = {}) => { ... }

Where:

• topic required The topic to send messages to.
• messages required an array of Pub/Sub messages. You can use the PubSub.helpers.createPubSubMessage method to easily create a Pub/Sub message.

PubSub.topics.list({ ... })

Lists all topics.

PubSub.helpers.createPubSubMessage({ ... })

Helps create a PubSub message easily.

Function definition:

const createPubSubMessage = ({ message = '', attributes = undefined } = {}) => { ... }

Where:

• message optional A message string. e.g. Hello World.
• attributes optional An object with string values. e.g. { type: 'slack-poll' }.
• ordering_key optional An ordering key to allow subscribers to receive messages in order in the same region. Read more here.

Returns a Pub/Sub message.

Cloudflare Workers Example

import base64url from 'base64url'
import PubSubREST from '@sagi.io/workers-pubsub'

const serviceAccountJSON = ...

const PubSub = await PubSubREST({ serviceAccountJSON })

const topic = 'gcf-task'
const psMessage = PubSub.helpers.createPubSubMessage({ message: 'Hello World!' })
const messages = [ psMessage ]

await PubSub.topics.publish({ topic, messages })

Node.js Example

import fetchImpl from 'cross-fetch'
import { Crypto }from 'node-webcrypto-ossl'
import PubSubREST from '@sagi.io/workers-pubsub'

const cryptoImpl = new Crypto()

const serviceAccountJSON = ...

const PubSub = await PubSubREST({ serviceAccountJSON, cryptoImpl. fetchImpl })

const topic = 'gcf-task'
const psMessage = PubSub.helpers.createPubSubMessage({ message: 'Hello World!' })
const messages = [ psMessage ]

await PubSub.topics.publish({ topic, messages })