Eseguire la connessione utilizzando i connettori di lingua AlloyDB

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;

public class AlloyDbJdbcConnectorDataSourceFactory {

  public static final String ALLOYDB_DB = System.getenv("ALLOYDB_DB");
  public static final String ALLOYDB_USER = System.getenv("ALLOYDB_USER");
  public static final String ALLOYDB_PASS = System.getenv("ALLOYDB_PASS");
  public static final String ALLOYDB_INSTANCE_NAME = System.getenv("ALLOYDB_INSTANCE_NAME");

  static HikariDataSource createDataSource() {
    HikariConfig config = new HikariConfig();

    config.setJdbcUrl(String.format("jdbc:postgresql:///%s", ALLOYDB_DB));
    config.setUsername(ALLOYDB_USER); // e.g., "postgres"
    config.setPassword(ALLOYDB_PASS); // e.g., "secret-password"
    config.addDataSourceProperty("socketFactory", "com.google.cloud.alloydb.SocketFactory");
    // e.g., "projects/my-project/locations/us-central1/clusters/my-cluster/instances/my-instance"
    config.addDataSourceProperty("alloydbInstanceName", ALLOYDB_INSTANCE_NAME);

    return new HikariDataSource(config);
  }
}

import sqlalchemy

from google.cloud.alloydbconnector import Connector


def create_sqlalchemy_engine(
    inst_uri: str,
    user: str,
    password: str,
    db: str,
    refresh_strategy: str = "background",
) -> tuple[sqlalchemy.engine.Engine, Connector]:
    """Creates a connection pool for an AlloyDB instance and returns the pool
    and the connector. Callers are responsible for closing the pool and the
    connector.

    A sample invocation looks like:

        engine, connector = create_sqlalchemy_engine(
            inst_uri,
            user,
            password,
            db,
        )
        with engine.connect() as conn:
            time = conn.execute(sqlalchemy.text("SELECT NOW()")).fetchone()
            conn.commit()
            curr_time = time[0]
            # do something with query result
            connector.close()

    Args:
        instance_uri (str):
            The instance URI specifies the instance relative to the project,
            region, and cluster. For example:
            "projects/my-project/locations/us-central1/clusters/my-cluster/instances/my-instance"
        user (str):
            The database user name, e.g., postgres
        password (str):
            The database user's password, e.g., secret-password
        db (str):
            The name of the database, e.g., mydb
        refresh_strategy (Optional[str]):
            Refresh strategy for the AlloyDB Connector. Can be one of "lazy"
            or "background". For serverless environments use "lazy" to avoid
            errors resulting from CPU being throttled.
    """
    connector = Connector(refresh_strategy=refresh_strategy)

    # create SQLAlchemy connection pool
    engine = sqlalchemy.create_engine(
        "postgresql+pg8000://",
        creator=lambda: connector.connect(
            inst_uri,
            "pg8000",
            user=user,
            password=password,
            db=db,
        ),
    )
    engine.dialect.description_encoding = None
    return engine, connector

import asyncpg
import sqlalchemy
import sqlalchemy.ext.asyncio

from google.cloud.alloydbconnector import AsyncConnector


async def create_sqlalchemy_engine(
    inst_uri: str,
    user: str,
    password: str,
    db: str,
    refresh_strategy: str = "background",
) -> tuple[sqlalchemy.ext.asyncio.engine.AsyncEngine, AsyncConnector]:
    """Creates a connection pool for an AlloyDB instance and returns the pool
    and the connector. Callers are responsible for closing the pool and the
    connector.

    A sample invocation looks like:

        engine, connector = await create_sqlalchemy_engine(
            inst_uri,
            user,
            password,
            db,
        )
        async with engine.connect() as conn:
            time = await conn.execute(sqlalchemy.text("SELECT NOW()")).fetchone()
            curr_time = time[0]
            # do something with query result
            await connector.close()

    Args:
        instance_uri (str):
            The instance URI specifies the instance relative to the project,
            region, and cluster. For example:
            "projects/my-project/locations/us-central1/clusters/my-cluster/instances/my-instance"
        user (str):
            The database user name, e.g., postgres
        password (str):
            The database user's password, e.g., secret-password
        db (str):
            The name of the database, e.g., mydb
        refresh_strategy (Optional[str]):
            Refresh strategy for the AlloyDB Connector. Can be one of "lazy"
            or "background". For serverless environments use "lazy" to avoid
            errors resulting from CPU being throttled.
    """
    connector = AsyncConnector(refresh_strategy=refresh_strategy)

    # create SQLAlchemy connection pool
    engine = sqlalchemy.ext.asyncio.create_async_engine(
        "postgresql+asyncpg://",
        async_creator=lambda: connector.connect(
            inst_uri,
            "asyncpg",
            user=user,
            password=password,
            db=db,
        ),
        execution_options={"isolation_level": "AUTOCOMMIT"},
    )
    return engine, connector

import (
	"context"
	"fmt"
	"net"

	"cloud.google.com/go/alloydbconn"
	"github.com/jackc/pgx/v5/pgxpool"
)

// connectPgx establishes a connection to your database using pgxpool and the
// AlloyDB Go Connector (aka alloydbconn.Dialer)
//
// The function takes an instance URI, a username, a password, and a database
// name. Usage looks like this:
//
//	pool, cleanup, err := connectPgx(
//	  context.Background(),
//	  "projects/myproject/locations/us-central1/clusters/mycluster/instances/myinstance",
//	  "postgres",
//	  "secretpassword",
//	  "mydb",
//	)
//
// In addition to a *pgxpool.Pool type, the function returns a cleanup function
// that should be called when you're done with the database connection.
func connectPgx(
	ctx context.Context, instURI, user, pass, dbname string,
	opts ...alloydbconn.Option,
) (*pgxpool.Pool, func() error, error) {
	// First initialize the dialer. alloydbconn.NewDialer accepts additional
	// options to configure credentials, timeouts, etc.
	//
	// For details, see:
	// https://pkg.go.dev/cloud.google.com/go/alloydbconn#Option
	d, err := alloydbconn.NewDialer(ctx, opts...)
	if err != nil {
		noop := func() error { return nil }
		return nil, noop, fmt.Errorf("failed to init Dialer: %v", err)
	}
	// The cleanup function will stop the dialer's background refresh
	// goroutines. Call it when you're done with your database connection to
	// avoid a goroutine leak.
	cleanup := func() error { return d.Close() }

	dsn := fmt.Sprintf(
		// sslmode is disabled, because the Dialer will handle the SSL
		// connection instead.
		"user=%s password=%s dbname=%s sslmode=disable",
		user, pass, dbname,
	)

	// Prefer pgxpool for applications.
	// For more information, see:
	// https://github.com/jackc/pgx/wiki/Getting-started-with-pgx#using-a-connection-pool
	config, err := pgxpool.ParseConfig(dsn)
	if err != nil {
		return nil, cleanup, fmt.Errorf("failed to parse pgx config: %v", err)
	}

	// Tell pgx to use alloydbconn.Dialer to connect to the instance.
	config.ConnConfig.DialFunc = func(ctx context.Context, _ string, _ string) (net.Conn, error) {
		return d.Dial(ctx, instURI)
	}

	// Establish the connection.
	pool, connErr := pgxpool.NewWithConfig(ctx, config)
	if connErr != nil {
		return nil, cleanup, fmt.Errorf("failed to connect: %s", connErr)
	}

	return pool, cleanup, nil
}

import (
	"database/sql"
	"fmt"

	"cloud.google.com/go/alloydbconn"
	"cloud.google.com/go/alloydbconn/driver/pgxv5"
)

// connectDatabaseSQL establishes a connection to your database using the Go
// standard library's database/sql package and using the AlloyDB Go Connector
// (aka alloydbconn.Dialer)
//
// The function takes an instance URI, a username, a password, and a database
// name. Usage looks like this:
//
//	db, cleanup, err := connectDatabaseSQL(
//	  "projects/myproject/locations/us-central1/clusters/mycluster/instances/myinstance",
//	  "postgres",
//	  "secretpassword",
//	  "mydb",
//	)
//
// In addition to a *db.SQL type, the function returns a cleanup function that
// should be called when you're done with the database connection.
func connectDatabaseSQL(
	instURI, user, pass, dbname string,
	opts ...alloydbconn.Option,
) (*sql.DB, func() error, error) {
	// First, register the AlloyDB driver. Note, the driver's name is arbitrary
	// and must only match what you use below in sql.Open. Also,
	// pgxv5.RegisterDriver accepts options to configure credentials, timeouts,
	// etc.
	//
	// For details, see:
	// https://pkg.go.dev/cloud.google.com/go/alloydbconn#Option
	//
	// The cleanup function will stop the dialer's background refresh
	// goroutines. Call it when you're done with your database connection to
	// avoid a goroutine leak.
	cleanup, err := pgxv5.RegisterDriver("alloydb", opts...)
	if err != nil {
		return nil, cleanup, err
	}

	db, err := sql.Open(
		"alloydb",
		fmt.Sprintf(
			// sslmode is disabled, because the Dialer will handle the SSL
			// connection instead.
			"host=%s user=%s password=%s dbname=%s sslmode=disable",
			instURI, user, pass, dbname,
		),
	)
	return db, cleanup, err
}