Expand OpenSearch SDK with aws sigv4 signing of requests on the Client using aws-opensearch-connector

ESClientBuilder.ts

import { defaultProvider } from '@aws-sdk/credential-provider-node';
import { Client } from '@opensearch-project/opensearch';

// tslint:disable-next-line:no-var-requires
const createAwsOpensearchConnector = require('aws-opensearch-connector');

export async function getEsClient(node: string = `https://${process.env.elasticsearch}`) {
    const es = new Client({
        ...createAwsOpensearchConnector({
            credentials: await defaultProvider()(),
            region: process.env.AWS_REGION || 'eu-central-1',
            getCredentials: (cb: () => void) => cb(),
        }),
        node,
    });
    return es;
}