Accessing an Elasticsearch Cluster Using Go
This section describes how to access a CSS cluster using Go.
Preparations
- The CSS cluster is available.
- Ensure that the server running Go can communicate with the CSS cluster.
- Ensure that Go has been installed on the server. You can download Go from the official website: https://go.dev/dl/.
Connecting to a Non-Security Mode Cluster
Connect to a non-security mode cluster. The sample code is as follows:
package mainimport ("github.com/elastic/go-elasticsearch/v7""log")func main() {cfg := elasticsearch.Config{Addresses: []string{"http://HOST:9200/",},}es, _ := elasticsearch.NewClient(cfg)log.Println(es.Info())}
In the information above, HOST indicates the internal IP address of a cluster node.
Connecting to a Security-Mode Cluster
- Connect to a security-mode cluster with HTTPS disabled. The sample code is as follows:package mainimport ("github.com/elastic/go-elasticsearch/v7""log")func main() {cfg := elasticsearch.Config{Addresses: []string{"http://HOST:9200/",},Username: "USERNAME",Password: "PASSWORD",}es, _ := elasticsearch.NewClient(cfg)log.Println(es.Info())}
- Connect to a security cluster that has enabled HTTPS and does not use certificates. The sample code is as follows:package mainimport ("crypto/tls""github.com/elastic/go-elasticsearch/v7""log""net/http")func main() {cfg := elasticsearch.Config{Addresses: []string{"https://HOST:9200/",},Username: "USERNAME",Password: "PASSWORD",Transport: &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true,},},}es, _ := elasticsearch.NewClient(cfg)log.Println(es.Info())}
- Connect to a security cluster that has enabled HTTPS and uses certificates. The sample code is as follows:package mainimport ("crypto/tls""crypto/x509""flag""github.com/elastic/go-elasticsearch/v7""io/ioutil""log""net""net/http""time")func main() {insecure := flag.Bool("insecure-ssl", false, "Accept/Ignore all server SSL certificates")flag.Parse()// Get the SystemCertPool, continue with an empty pool on errorrootCAs, _ := x509.SystemCertPool()if rootCAs == nil {rootCAs = x509.NewCertPool()}// Read in the cert filecerts, err := ioutil.ReadFile("/tmp/CloudSearchService.cer")if err != nil {log.Fatalf("Failed to append %q to RootCAs: %v", "xxx", err)}// Append our cert to the system poolif ok := rootCAs.AppendCertsFromPEM(certs); !ok {log.Println("No certs appended, using system certs only")}config := elasticsearch.Config{Addresses: []string{"https://HOST:9200/",},Username: "USERNAME",Password: "PASSWORD",Transport: &http.Transport{MaxIdleConnsPerHost: 10,ResponseHeaderTimeout: time.Second,DialContext: (&net.Dialer{Timeout: 30 * time.Second,KeepAlive: 30 * time.Second,}).DialContext,TLSClientConfig: &tls.Config{InsecureSkipVerify: *insecure,RootCAs: rootCAs,},},}es, _ := elasticsearch.NewClient(config)log.Println(elasticsearch.Version)log.Println(es.Info())}
Parameter | Description |
---|---|
HOST | IP address for accessing the Elasticsearch cluster. If there are multiple IP addresses, separate them with commas (,). |
USERNAME | Username for accessing the cluster. |
PASSWORD | Password of the user. |
Running Code
Write the code above to the EsTest.gc file based on the cluster type and save the file to an independent directory. Run the following command in that directory to run the code:
go env -w GO111MODULE=ongo env -w GOPROXY=https://goproxy.io,directgo env -w GONOSUMDB=*go mod init testgo mod tidygo run EsTest.go
Parent topic: Accessing Elasticsearch Clusters
- Preparations
- Connecting to a Non-Security Mode Cluster
- Connecting to a Security-Mode Cluster
- Running Code