Can't connect to Elasticsearch with Node.Js on Kubernetes (socket hang up)

I have a NodeJs application running inside a Kubernetes cluster. I’ve also followed the official steps to setup Elasticsearch on Kubernetes.

I am not sure if this has actually something to do with elasticsearch-js or if I am doing something wrong here.

Issue

I am unable to connect to the Elasticsearch cluster. I get this error:

ConnectionError: socket hang up

This is a code snippet of my connection:

const client = new elasticsearch.Client({
  node: process.env.elasticsearch_node, // http://elasticsearch-es-http.default.svc.cluster.local:9200
});

Minimal reproduction

I’ve created a minimal reproduction of this issue here: https://github.com/flolu/elasticsearch-k8s-connection. (Setup instructions are in the README)

Basically, everything works fine when running Elasticsearch inside Docker compose, but I can’t connect when running inside Kubernetes.

[delvedor]

Given that you are using a self-signed certificate, you should also set rejectUnauthorized to false:

const { Client } = require('@elastic/elasticsearch')
const client = new Client({
  node: 'https://localhost:9200',
  auth: {
    username: 'elastic',
    password: 'changeme'
  },
  ssl: {
    ca: fs.readFileSync('./cacert.pem'),
    rejectUnauthorized: false
  }
})

You can find the SSL documentation here.

[delvedor]

Glad you were able to sort it out! Yeah, it’s fine to use it as long as you trust that certificate. By default, Node.js rejects certificates that didn’t use an official CA authority, but given that you have created that cert via Elasticsearch, it’s safe to use.

Closing this, feel free to reopen if you have other questions! 😃