asStreamedit

Instead of getting the parsed body back, you will get the raw Node.js stream of data.

'use strict'

const { Client } = require('@elastic/elasticsearch')
const client = new Client({ node: 'http://localhost:9200' })

async function run () {
  const { body: bulkResponse } = await client.bulk({
    refresh: true,
    body: [
      // operation to perform
      { index: { _index: 'game-of-thrones' } },
      // the document to index
      {
        character: 'Ned Stark',
        quote: 'Winter is coming.'
      },

      { index: { _index: 'game-of-thrones' } },
      {
        character: 'Daenerys Targaryen',
        quote: 'I am the blood of the dragon.'
      },

      { index: { _index: 'game-of-thrones' } },
      {
        character: 'Tyrion Lannister',
        quote: 'A mind needs books like a sword needs a whetstone.'
      }
    ]
  })

  if (bulkResponse.errors) {
    console.log(bulkResponse)
    process.exit(1)
  }

  // Let's search!
  const { body } = await client.search({
    index: 'game-of-thrones',
    body: {
      query: {
        match: {
          quote: 'winter'
        }
      }
    }
  }, {
    asStream: true
  })

  // stream async iteration, available in Node.js ≥ 10
  var payload = ''
  body.setEncoding('utf8')
  for await (const chunk of body) {
    payload += chunk
  }
  console.log(JSON.parse(payload))

  // classic stream callback style
  var payload = ''
  body.setEncoding('utf8')
  body.on('data', chunk => { payload += chunk })
  body.on('error', console.log)
  body.on('end', () => {
    console.log(JSON.parse(payload))
  })
}

run().catch(console.log)
Tip

This can be useful if you need to pipe the Elasticsearch’s response to a proxy, or send it directly to another source.

'use strict'

const { Client } = require('@elastic/elasticsearch')
const client = new Client({ node: 'http://localhost:9200' })
const fastify = require('fastify')()

fastify.post('/search/:index', async (req, reply) => {
  const { body, statusCode, headers } = await client.search({
    index: req.params.index,
    body: req.body
  }, {
    asStream: true
  })

  reply.code(statusCode).headers(headers)
  return body
})

fastify.listen(3000)