@jalavosus/graphql-kafka-subscriptions

graphql-kafka-subscriptions

Apollo graphql subscriptions over Kafka protocol

One producer and one consumer for each node instance. Communication happens over a single kafka topic.

Installation

npm install graphql-kafka-subscriptions

Mac OS High Sierra / Mojave

OpenSSL has been upgraded in High Sierra and homebrew does not overwrite default system libraries. That means when building node-rdkafka, because you are using openssl, you need to tell the linker where to find it:

export CPPFLAGS=-I/usr/local/opt/openssl/include
export LDFLAGS=-L/usr/local/opt/openssl/lib

Then you can run npm install on your application to get it to build correctly.

Usage

import { KafkaPubSub } from 'graphql-kafka-subscriptions'

export const pubsub = new KafkaPubSub({
  topic: 'anything',
  host: 'INSERT_KAFKA_IP',
  port: 'INSERT_KAFKA_PORT',
  globalConfig: {} // options passed directly to the consumer and producer
})

With multiple Kafka nodes

export const pubsub = new KafkaPubSub({
  topic: 'anything',
  host: 'kafka-10.development.foobar.com:9092,kafka-21.development.foobar.com:9092,kafka-22.development.foobar.com:9092',
})

// as mentioned in the comments of https://github.com/ancashoria/graphql-kafka-subscriptions/issues/4
// you will need to upate the site calls of `publish` in your application as called out below.

// the stock PubSub::publish expects a string and an object
      pubsub.publish('messageAdded', {
        messageAdded: newMessage,
        channelId: message.channelId
      });

// KafkaPubSub::publish expects the first parameter to be inserted into the object
      pubsub.publish({
        channel: 'messageAdded',
        messageAdded: newMessage,
        channelId: message.channelId
      });

Special thanks to:

• davidyaha for graphql-redis-subscriptions which was the main inspiration point for this project
• Apollo graphql community

Help greatly appreciated