Start a VM instance

Restart a stopped VM instance.

Explore further

For detailed documentation that includes this code sample, see the following:

• Stop or restart a Compute Engine instance

Code sample

Go

Before trying this sample, follow the Go setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Go API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"context"
	"fmt"
	"io"

	compute "cloud.google.com/go/compute/apiv1"
	computepb "cloud.google.com/go/compute/apiv1/computepb"
)

// startInstance starts a stopped Google Compute Engine instance (with unencrypted disks).
func startInstance(w io.Writer, projectID, zone, instanceName string) error {
	// projectID := "your_project_id"
	// zone := "europe-central2-b"
	// instanceName := "your_instance_name"

	ctx := context.Background()
	instancesClient, err := compute.NewInstancesRESTClient(ctx)
	if err != nil {
		return fmt.Errorf("NewInstancesRESTClient: %w", err)
	}
	defer instancesClient.Close()

	req := &computepb.StartInstanceRequest{
		Project:  projectID,
		Zone:     zone,
		Instance: instanceName,
	}

	op, err := instancesClient.Start(ctx, req)
	if err != nil {
		return fmt.Errorf("unable to start instance: %w", err)
	}

	if err = op.Wait(ctx); err != nil {
		return fmt.Errorf("unable to wait for the operation: %w", err)
	}

	fmt.Fprintf(w, "Instance started\n")

	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Java API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import com.google.api.gax.longrunning.OperationFuture;
import com.google.cloud.compute.v1.InstancesClient;
import com.google.cloud.compute.v1.Operation;
import com.google.cloud.compute.v1.Operation.Status;
import com.google.cloud.compute.v1.StartInstanceRequest;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class StartInstance {

  public static void main(String[] args)
      throws IOException, ExecutionException, InterruptedException, TimeoutException {
    // TODO(developer): Replace these variables before running the sample.
    /* project: project ID or project number of the Cloud project your instance belongs to.
       zone: name of the zone your instance belongs to.
       instanceName: name of the instance your want to start. */
    String project = "your-project-id";
    String zone = "zone-name";
    String instanceName = "instance-name";

    startInstance(project, zone, instanceName);
  }

  // Starts a stopped Google Compute Engine instance (with unencrypted disks).
  public static void startInstance(String project, String zone, String instanceName)
      throws IOException, ExecutionException, InterruptedException, TimeoutException {
    /* Initialize client that will be used to send requests. This client only needs to be created
       once, and can be reused for multiple requests. After completing all of your requests, call
       the `instancesClient.close()` method on the client to safely
       clean up any remaining background resources. */
    try (InstancesClient instancesClient = InstancesClient.create()) {

      // Create the request.
      StartInstanceRequest startInstanceRequest = StartInstanceRequest.newBuilder()
          .setProject(project)
          .setZone(zone)
          .setInstance(instanceName)
          .build();

      OperationFuture<Operation, Operation> operation = instancesClient.startAsync(
          startInstanceRequest);

      // Wait for the operation to complete.
      Operation response = operation.get(3, TimeUnit.MINUTES);

      if (response.getStatus() == Status.DONE) {
        System.out.println("Instance started successfully ! ");
      }
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Node.js API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

/**
 * TODO(developer): Uncomment and replace these variables before running the sample.
 */
// const projectId = 'YOUR_PROJECT_ID';
// const zone = 'europe-central2-b'
// const instanceName = 'YOUR_INSTANCE_NAME'

const compute = require('@google-cloud/compute');

async function startInstance() {
  const instancesClient = new compute.InstancesClient();

  const [response] = await instancesClient.start({
    project: projectId,
    zone,
    instance: instanceName,
  });
  let operation = response.latestResponse;
  const operationsClient = new compute.ZoneOperationsClient();

  // Wait for the operation to complete.
  while (operation.status !== 'DONE') {
    [operation] = await operationsClient.wait({
      operation: operation.name,
      project: projectId,
      zone: operation.zone.split('/').pop(),
    });
  }

  console.log('Instance started.');
}

startInstance();

PHP

Before trying this sample, follow the PHP setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine PHP API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

use Google\Cloud\Compute\V1\Client\InstancesClient;
use Google\Cloud\Compute\V1\StartInstanceRequest;

/**
 * Starts a stopped Google Compute Engine instance (with unencrypted disks).
 *
 * @param string $projectId Project ID or project number of the Cloud project your instance belongs to.
 * @param string $zone Name of the zone your instance belongs to.
 * @param string $instanceName Name of the instance you want to stop.
  *
 * @throws \Google\ApiCore\ApiException if the remote call fails.
 * @throws \Google\ApiCore\ValidationException if local error occurs before remote call.
 */
function start_instance(
    string $projectId,
    string $zone,
    string $instanceName
) {
    // Start the Compute Engine instance using InstancesClient.
    $instancesClient = new InstancesClient();
    $request = (new StartInstanceRequest())
        ->setInstance($instanceName)
        ->setProject($projectId)
        ->setZone($zone);
    $operation = $instancesClient->start($request);

    // Wait for the operation to complete.
    $operation->pollUntilComplete();
    if ($operation->operationSucceeded()) {
        printf('Instance %s started successfully' . PHP_EOL, $instanceName);
    } else {
        $error = $operation->getError();
        printf('Failed to start instance: %s' . PHP_EOL, $error?->getMessage());
    }
}

Python

Before trying this sample, follow the Python setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Python API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

from __future__ import annotations

import sys
from typing import Any

from google.api_core.extended_operation import ExtendedOperation
from google.cloud import compute_v1


def wait_for_extended_operation(
    operation: ExtendedOperation, verbose_name: str = "operation", timeout: int = 300
) -> Any:
    """
    Waits for the extended (long-running) operation to complete.

    If the operation is successful, it will return its result.
    If the operation ends with an error, an exception will be raised.
    If there were any warnings during the execution of the operation
    they will be printed to sys.stderr.

    Args:
        operation: a long-running operation you want to wait on.
        verbose_name: (optional) a more verbose name of the operation,
            used only during error and warning reporting.
        timeout: how long (in seconds) to wait for operation to finish.
            If None, wait indefinitely.

    Returns:
        Whatever the operation.result() returns.

    Raises:
        This method will raise the exception received from `operation.exception()`
        or RuntimeError if there is no exception set, but there is an `error_code`
        set for the `operation`.

        In case of an operation taking longer than `timeout` seconds to complete,
        a `concurrent.futures.TimeoutError` will be raised.
    """
    result = operation.result(timeout=timeout)

    if operation.error_code:
        print(
            f"Error during {verbose_name}: [Code: {operation.error_code}]: {operation.error_message}",
            file=sys.stderr,
            flush=True,
        )
        print(f"Operation ID: {operation.name}", file=sys.stderr, flush=True)
        raise operation.exception() or RuntimeError(operation.error_message)

    if operation.warnings:
        print(f"Warnings during {verbose_name}:\n", file=sys.stderr, flush=True)
        for warning in operation.warnings:
            print(f" - {warning.code}: {warning.message}", file=sys.stderr, flush=True)

    return result


def start_instance(project_id: str, zone: str, instance_name: str) -> None:
    """
    Starts a stopped Google Compute Engine instance (with unencrypted disks).
    Args:
        project_id: project ID or project number of the Cloud project your instance belongs to.
        zone: name of the zone your instance belongs to.
        instance_name: name of the instance your want to start.
    """
    instance_client = compute_v1.InstancesClient()

    operation = instance_client.start(
        project=project_id, zone=zone, instance=instance_name
    )

    wait_for_extended_operation(operation, "instance start")

What's next

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