Authentication using the metadata service

package main

import (
  "context"
  "database/sql"
  "os"

  "github.com/ydb-platform/ydb-go-sdk/v3"
  yc "github.com/ydb-platform/ydb-go-yc"
)

func main() {
  ctx, cancel := context.WithCancel(context.Background())
  defer cancel()
  nativeDriver, err := ydb.Open(ctx,
    os.Getenv("YDB_CONNECTION_STRING"),
    yc.WithMetadataCredentials(ctx),
    yc.WithInternalCA(), // append Yandex Cloud certificates
  )
  if err != nil {
    panic(err)
  }
  defer nativeDriver.Close(ctx) 
  connector, err := ydb.Connector(nativeDriver)
  if err != nil {
    panic(err)
  }
  db := sql.OpenDB(connector)
  defer db.Close()
  ...
}

public void work(String connectionString) {
    AuthProvider authProvider = CloudAuthHelper.getMetadataAuthProvider(); 

    GrpcTransport transport = GrpcTransport.forConnectionString(connectionString)
            .withAuthProvider(authProvider)
            .build());
    
    TableClient tableClient = TableClient.newClient(transport).build();

    doWork(tableClient);

    tableClient.close();
    transport.close();
}

using Ydb.Sdk;
using Ydb.Sdk.Yc;

var metadataProvider = new MetadataProvider();

// Await initial IAM token.
await metadataProvider.Initialize();

var config = new DriverConfig(
    endpoint: endpoint, // Database endpoint, "grpcs://host:port"
    database: database, // Full database path
    credentials: metadataProvider
);

await using var driver = await Driver.CreateInitialized(config);

<?php

use YdbPlatform\Ydb\Ydb;
use YdbPlatform\Ydb\Auth\Implement\MetadataAuthentication;

$config = [

    // Database path
    'database'    => '/local',

    // Database endpoint
    'endpoint'    => 'localhost:2136',

    // Auto discovery (dedicated server only)
    'discovery'   => false,

    // IAM config
    'iam_config'  => [
        'insecure' => true,
        // 'root_cert_file' => './CA.pem', // Root CA file (uncomment for dedicated server)
    ],
    
    'credentials' => new MetadataAuthentication()
];

$ydb = new Ydb($config);