prisme-flow/nodes/bridge/kafka/kafka.js

prisme platform flow engine

/**
 * Created by prisme.io on 09/06/2017.
 */
module.exports = function (RED) {
    /*
     *   Kafka Producer
     *   Parameters:
     - topics
     - zkquorum(example: zkquorum = “[host]:2181")
     */
  function kafkaNode (config) {
    RED.nodes.createNode(this, config)
    var topic = config.topic
    var clusterZookeeper = config.zkquorum
    var debug = (config.debug == 'debug')
    var node = this
    var kafka = require('kafka-node')
    var HighLevelProducer = kafka.HighLevelProducer
    var Client = kafka.Client
    var topics = config.topics
    var client = new Client(clusterZookeeper)

    try {
      this.on('input', function (msg) {
        var payloads = []

                // check if multiple topics
        if (topics.indexOf(',') > -1) {
          var topicArry = topics.split(',')

          for (i = 0; i < topicArry.length; i++) {
            payloads.push({topic: topicArry[i], messages: msg.payload})
          }
        } else {
          payloads = [{topic: topics, messages: msg.payload}]
        }

        producer.send(payloads, function (err, data) {
          if (err) {
            node.error(err)
          }
          node.log('Message Sent: ' + data)
        })
      })
    } catch (e) {
      node.error(e)
    }
    var producer = new HighLevelProducer(client)
    this.status({fill: 'green', shape: 'dot', text: 'connected to ' + clusterZookeeper})
  }

  RED.nodes.registerType('kafka', kafkaNode)

    /*
     *   Kafka Consumer
     *   Parameters:
     - topics
     - groupId
     - zkquorum(example: zkquorum = “[host]:2181")
     */
  function kafkaInNode (config) {
    RED.nodes.createNode(this, config)

    var node = this

    var kafka = require('kafka-node')
    var HighLevelConsumer = kafka.HighLevelConsumer
    var Client = kafka.Client
    var topics = String(config.topics)
    var clusterZookeeper = config.zkquorum
    var groupId = config.groupId
    var debug = (config.debug == 'debug')
    var client = new Client(clusterZookeeper)

    var topicJSONArry = []

        // check if multiple topics
    if (topics.indexOf(',') > -1) {
      var topicArry = topics.split(',')
      if (debug) {
        console.log(topicArry)
        console.log(topicArry.length)
      }

      for (i = 0; i < topicArry.length; i++) {
        if (debug) {
          console.log(topicArry[i])
        }
        topicJSONArry.push({topic: topicArry[i]})
      }
      topics = topicJSONArry
    } else {
      topics = [{topic: topics}]
    }

    var options = {
      groupId: groupId,
      autoCommit: config.autoCommit,
      autoCommitMsgCount: 10
    }

    try {
      var consumer = new HighLevelConsumer(client, topics, options)
      this.log('Consumer created...')
      this.status({fill: 'green', shape: 'dot', text: 'connected to ' + clusterZookeeper})

      consumer.on('message', function (message) {
        if (debug) {
          console.log(message)
          node.log(message)
        }
        var msg = {payload: message}
        node.send(msg)
      })

      consumer.on('error', function (err) {
        console.error(err)
      })
    } catch (e) {
      node.error(e)
    }
  }

  RED.nodes.registerType('kafka in', kafkaInNode)
}