airflow-dags/reference/providers/google/cloud/example_dags/example_compute_igm.py

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"""
Example Airflow DAG that uses IGM-type compute operations:
* copy of Instance Template
* update template in Instance Group Manager

This DAG relies on the following OS environment variables

* GCP_PROJECT_ID - the Google Cloud project where the Compute Engine instance exists
* GCE_ZONE - the zone where the Compute Engine instance exists

Variables for copy template operator:
* GCE_TEMPLATE_NAME - name of the template to copy
* GCE_NEW_TEMPLATE_NAME - name of the new template
* GCE_NEW_DESCRIPTION - description added to the template

Variables for update template in Group Manager:

* GCE_INSTANCE_GROUP_MANAGER_NAME - name of the Instance Group Manager
* SOURCE_TEMPLATE_URL - url of the template to replace in the Instance Group Manager
* DESTINATION_TEMPLATE_URL - url of the new template to set in the Instance Group Manager
"""

import os

from airflow import models
from airflow.providers.google.cloud.operators.compute import (
    ComputeEngineCopyInstanceTemplateOperator,
    ComputeEngineInstanceGroupUpdateManagerTemplateOperator,
)
from airflow.utils.dates import days_ago

GCP_PROJECT_ID = os.environ.get("GCP_PROJECT_ID", "example-project")
GCE_ZONE = os.environ.get("GCE_ZONE", "europe-west1-b")

# [START howto_operator_compute_template_copy_args]
GCE_TEMPLATE_NAME = os.environ.get("GCE_TEMPLATE_NAME", "instance-template-test")
GCE_NEW_TEMPLATE_NAME = os.environ.get(
    "GCE_NEW_TEMPLATE_NAME", "instance-template-test-new"
)
GCE_NEW_DESCRIPTION = os.environ.get("GCE_NEW_DESCRIPTION", "Test new description")
GCE_INSTANCE_TEMPLATE_BODY_UPDATE = {
    "name": GCE_NEW_TEMPLATE_NAME,
    "description": GCE_NEW_DESCRIPTION,
    "properties": {"machineType": "n1-standard-2"},
}
# [END howto_operator_compute_template_copy_args]

# [START howto_operator_compute_igm_update_template_args]
GCE_INSTANCE_GROUP_MANAGER_NAME = os.environ.get(
    "GCE_INSTANCE_GROUP_MANAGER_NAME", "instance-group-test"
)

SOURCE_TEMPLATE_URL = os.environ.get(
    "SOURCE_TEMPLATE_URL",
    "https://www.googleapis.com/compute/beta/projects/"
    + GCP_PROJECT_ID
    + "/global/instanceTemplates/instance-template-test",
)

DESTINATION_TEMPLATE_URL = os.environ.get(
    "DESTINATION_TEMPLATE_URL",
    "https://www.googleapis.com/compute/beta/projects/"
    + GCP_PROJECT_ID
    + "/global/instanceTemplates/"
    + GCE_NEW_TEMPLATE_NAME,
)

UPDATE_POLICY = {
    "type": "OPPORTUNISTIC",
    "minimalAction": "RESTART",
    "maxSurge": {"fixed": 1},
    "minReadySec": 1800,
}

# [END howto_operator_compute_igm_update_template_args]


with models.DAG(
    "example_gcp_compute_igm",
    schedule_interval=None,  # Override to match your needs
    start_date=days_ago(1),
    tags=["example"],
) as dag:
    # [START howto_operator_gce_igm_copy_template]
    gce_instance_template_copy = ComputeEngineCopyInstanceTemplateOperator(
        project_id=GCP_PROJECT_ID,
        resource_id=GCE_TEMPLATE_NAME,
        body_patch=GCE_INSTANCE_TEMPLATE_BODY_UPDATE,
        task_id="gcp_compute_igm_copy_template_task",
    )
    # [END howto_operator_gce_igm_copy_template]
    # Added to check for idempotence
    # [START howto_operator_gce_igm_copy_template_no_project_id]
    gce_instance_template_copy2 = ComputeEngineCopyInstanceTemplateOperator(
        resource_id=GCE_TEMPLATE_NAME,
        body_patch=GCE_INSTANCE_TEMPLATE_BODY_UPDATE,
        task_id="gcp_compute_igm_copy_template_task_2",
    )
    # [END howto_operator_gce_igm_copy_template_no_project_id]
    # [START howto_operator_gce_igm_update_template]
    gce_instance_group_manager_update_template = (
        ComputeEngineInstanceGroupUpdateManagerTemplateOperator(
            project_id=GCP_PROJECT_ID,
            resource_id=GCE_INSTANCE_GROUP_MANAGER_NAME,
            zone=GCE_ZONE,
            source_template=SOURCE_TEMPLATE_URL,
            destination_template=DESTINATION_TEMPLATE_URL,
            update_policy=UPDATE_POLICY,
            task_id="gcp_compute_igm_group_manager_update_template",
        )
    )
    # [END howto_operator_gce_igm_update_template]
    # Added to check for idempotence (and without UPDATE_POLICY)
    # [START howto_operator_gce_igm_update_template_no_project_id]
    gce_instance_group_manager_update_template2 = (
        ComputeEngineInstanceGroupUpdateManagerTemplateOperator(
            resource_id=GCE_INSTANCE_GROUP_MANAGER_NAME,
            zone=GCE_ZONE,
            source_template=SOURCE_TEMPLATE_URL,
            destination_template=DESTINATION_TEMPLATE_URL,
            task_id="gcp_compute_igm_group_manager_update_template_2",
        )
    )
    # [END howto_operator_gce_igm_update_template_no_project_id]

    gce_instance_template_copy >> gce_instance_template_copy2 >> gce_instance_group_manager_update_template
    gce_instance_group_manager_update_template >> gce_instance_group_manager_update_template2