create_from_instance.py

#  Copyright 2022 Google LLC
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
# flake8: noqa


# This file is automatically generated. Please do not modify it directly.
# Find the relevant recipe file in the samples/recipes or samples/ingredients
# directory and apply your changes there.


# [START compute_template_create_from_instance]
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:
    """
    This method will wait 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 create_template_from_instance(
    project_id: str, instance: str, template_name: str
) -> compute_v1.InstanceTemplate:
    """
    Create a new instance template based on an existing instance.
    This new template specifies a different boot disk.

    Args:
        project_id: project ID or project number of the Cloud project you use.
        instance: the instance to base the new template on. This value uses
            the following format: "projects/{project}/zones/{zone}/instances/{instance_name}"
        template_name: name of the new template to create.

    Returns:
        InstanceTemplate object that represents the new instance template.
    """
    disk = compute_v1.DiskInstantiationConfig()
    # Device name must match the name of a disk attached to the instance you are
    # basing your template on.
    disk.device_name = "disk-1"
    # Replace the original boot disk image used in your instance with a Rocky Linux image.
    disk.instantiate_from = "CUSTOM_IMAGE"
    disk.custom_image = "projects/rocky-linux-cloud/global/images/family/rocky-linux-8"
    # Override the auto_delete setting.
    disk.auto_delete = True

    template = compute_v1.InstanceTemplate()
    template.name = template_name
    template.source_instance = instance
    template.source_instance_params = compute_v1.SourceInstanceParams()
    template.source_instance_params.disk_configs = [disk]

    template_client = compute_v1.InstanceTemplatesClient()
    operation = template_client.insert(
        project=project_id, instance_template_resource=template
    )

    wait_for_extended_operation(operation, "instance template creation")

    return template_client.get(project=project_id, instance_template=template_name)


# [END compute_template_create_from_instance]