Code examples for connecting to a OpenSearch cluster

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Updated at March 5, 2026

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Python

Before connecting, prepare a certificate.

To connect, enter admin for the username and the password you set when creating the cluster.

To see code examples with the host FQDN filled in, open the cluster page in the management console and click Connect.

Go

Before connecting, install the required dependencies:

go mod init opensearch-example && \
go get github.com/opensearch-project/opensearch-go

Connecting with SSL

Code example:

connect.go

package main

import (
	"crypto/tls"
	"crypto/x509"
	"crypto/x509"
	"github.com/opensearch-project/opensearch-go"
	"io/ioutil"
	"log"
	"net/http"
)

var hosts = []string{
	"<FQDN_of_host_1_with_DATA_role>:9200",
	...,
	"<FQDN_of_host_N_with_DATA_role>:9200"
	}

var CA = "/home/<home_directory>/.opensearch/root.crt"

var password = "<password>"

func main() {
	caCert, err := ioutil.ReadFile(CA)
	if err != nil {
		log.Fatal(err)
	}
	caCertPool := x509.NewCertPool()
	caCertPool.AppendCertsFromPEM(caCert)

	cfg := opensearch.Config{
		Addresses: hosts,
		Transport: &http.Transport{
			TLSClientConfig: &tls.Config{
				RootCAs: caCertPool,
			},
		},
		Username: "admin",
		Password: password,
	}
	es, err := opensearch.NewClient(cfg)
	if err != nil {
		log.Printf("Error creating the client: %s", err)
	} else {
		log.Println(es.Info())
	}
}

Unlike other connection methods, in this example, you need to use the full path to the CA.pem certificate for OpenSearch in the CA variable.

Connecting:
```
go run connect.go
```

To learn how to get a host FQDN, see this guide.

Python

Before connecting, install the required dependencies:

sudo apt update && sudo apt install --yes python3 python3-pip && \
pip3 install opensearch-py

Connecting with SSL

Code example:

connect.py

from opensearchpy import OpenSearch

CA = '~/.opensearch/root.crt'
PASS = '<password>'
HOSTS = [
  "<FQDN_of_host_1_with_DATA_role>",
  ...,
  "<FQDN_of_host_N_with_DATA_role>"
]

conn = OpenSearch(
  HOSTS,
  http_auth=('admin', PASS),
  use_ssl=True,
  verify_certs=True,
  ca_certs=CA)

print(conn.info())

Connecting:
```
python3 connect.py
```

To learn how to get a host FQDN, see this guide.

Code examples for connecting to a OpenSearch cluster

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