unable to connect to elasticsearch service using AWS lambda - node.js

Question

I am running my lambdas on port:4566 using localstack using below image
version: "2.1"
services:
localstack:
image: "localstack/localstack"
container_name: "localstack"
ports:
- "4566-4620:4566-4620"
- "127.0.0.1:8055:8080"
environment:
- SERVICES=s3,es,dynamodb,apigateway,lambda,sns,sqs,sloudformation
- DEBUG=1
- EDGE_PORT=4566
- DATA_DIR=/var/lib/localstack/data
- DOCKER_HOST=unix:///var/run/docker.sock
- HOST_TMP_FOLDER=${TMPDIR}
- LAMBDA_EXECUTOR=docker
- DYNAMODB_SHARE_DB=1
- DISABLE_CORS_CHECKS=1
- AWS_DDB_ENDPOINT=http://localhost:4566
volumes:
- "${TMPDIR:-/var/lib/localstack}:/var/lib/localstack"
- "/var/run/docker.sock:/var/run/docker.sock"
networks:
- "local"
elasticsearch:
container_name: tqd-elasticsearch
image: docker.elastic.co/elasticsearch/elasticsearch:7.0.1
# volumes:
# - esdata:/usr/share/elasticsearch/data
environment:
- bootstrap.memory_lock=true
- "ES_JAVA_OPTS=-Xms512m -Xmx512m"
- discovery.type=single-node
depends_on:
- "localstack"
logging:
driver: none
ports:
- 9300:9300
- 9200:9200
networks:
- "local"
networks:
local:
driver: "bridge"
Problem: Not getting any response from elasticsearch while calling it from lambda
This is my lambda code
module.exports.createIndex = async () => {
const elasticClient = new Client({
node: "http://localhost:9200"
});
console.log("before the client call")
console.log(getIndices().then(res => { console.log(res) }).catch(err => {
console.log(err)
}))
console.log("after the client call")
const getIndices = async () =>
{
return await elasticClient.indices.create({
index:"index-from-lambda"
})
}
return {
statusCode: 201,
body: JSON.stringify({
msg:"index created successfully"
})
}
}
logs on my docker image,
before the client call
Promise { <pending> }
console.log("after the client call")
After this even when i go to bash and validate whether this index has been created or not , it returns empty set of indexes i.e. no index has been created
But, the same code works fine i.e. creates index on elasticsearch at port 9200 while called from httpserver #port 3000 and from standalone javascript file
standalone server code
const express = require('express')
const app = express();
const { Client } = require('#elastic/elasticsearch');
const elasticClient = new Client({
node: "http://localhost:9200"
});
app.listen(3000, () => {
console.log('listening to the port 3000')
})
const getIndices = async () =>
{
return await elasticClient.cat.indices()
}
console.log(getIndices().then(res => { console.log(res) }).catch(err => {
console.log(err)
}))
this is standalone js script
const { Client } = require('#elastic/elasticsearch');
const elasticClient = new Client({
node: "http://localhost:9200"
});
const getIndices = async () =>
{
return await elasticClient.cat.indices()
}
console.log(getIndices().then(res => { console.log(res) }).catch(err => {
console.log(err)
}))
Is this any kind of networking error or docker image error?

Answer 1

This issue has been listed out here,
The problem is with the endpoint.
So localhost actually addresses your docker container, not your host machine.
If you run your express server on the host, please use host.docker.internal as hostname, which will address the host from your docker container.
Same is the thing with Elasticsearch image.
Now code becomes,
elasticClient = new Client({
node:"http://host.docker.internal:9200"
})
Rest remains the same.