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Google Cloud Functions Operators
================================

.. contents::
  :depth: 1
  :local:

.. _howto/operator:GcfFunctionDeleteOperator:

GcfFunctionDeleteOperator
-------------------------

Use the operator to delete a function from Google Cloud Functions.

For parameter definition, take a look at
:class:`~airflow.contrib.operators.gcp_function_operator.GcfFunctionDeleteOperator`.

Arguments
"""""""""

The following examples of OS environment variables show how you can build function name
to use in the operator:

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :start-after: [START howto_operator_gcf_common_variables]
    :end-before: [END howto_operator_gcf_common_variables]

Using the operator
""""""""""""""""""

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :dedent: 4
    :start-after: [START howto_operator_gcf_delete]
    :end-before: [END howto_operator_gcf_delete]

Templating
""""""""""

.. literalinclude:: ../../../../airflow/contrib/operators/gcp_function_operator.py
    :language: python
    :dedent: 4
    :start-after: [START gcf_function_delete_template_fields]
    :end-before: [END gcf_function_delete_template_fields]

More information
""""""""""""""""

See Google Cloud Functions API documentation to `delete a function
<https://cloud.google.com/functions/docs/reference/rest/v1/projects.locations.functions/delete>`_.

.. _howto/operator:GcfFunctionDeployOperator:

GcfFunctionDeployOperator
-------------------------

Use the operator to deploy a function to Google Cloud Functions.
If a function with this name already exists, it will be updated.

For parameter definition, take a look at
:class:`~airflow.contrib.operators.gcp_function_operator.GcfFunctionDeployOperator`.


Arguments
"""""""""

In the example DAG the following environment variables are used to parameterize the
operator's definition:

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :start-after: [START howto_operator_gcf_common_variables]
    :end-before: [END howto_operator_gcf_common_variables]

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :start-after: [START howto_operator_gcf_deploy_variables]
    :end-before: [END howto_operator_gcf_deploy_variables]

Some of those variables are used to create the request's body:

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :start-after: [START howto_operator_gcf_deploy_body]
    :end-before: [END howto_operator_gcf_deploy_body]

When a DAG is created, the default_args dictionary can be used to pass
arguments common with other tasks:

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :start-after: [START howto_operator_gcf_default_args]
    :end-before: [END howto_operator_gcf_default_args]

Note that the neither the body nor the default args are complete in the above examples.
Depending on the variables set, there might be different variants on how to pass source
code related fields. Currently, you can pass either ``sourceArchiveUrl``,
``sourceRepository`` or ``sourceUploadUrl`` as described in the
`Cloud Functions API specification
<https://cloud.google.com/functions/docs/reference/rest/v1/projects.locations.functions#CloudFunction>`_.

Additionally, ``default_args`` or direct operator args might contain ``zip_path``
parameter
to run the extra step of uploading the source code before deploying it.
In this case, you also need to provide an empty ``sourceUploadUrl``
parameter in the body.

Using the operator
""""""""""""""""""

Depending on the combination of parameters, the Function's source code can be obtained
from different sources:

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :start-after: [START howto_operator_gcf_deploy_variants]
    :end-before: [END howto_operator_gcf_deploy_variants]

The code to create the operator:

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :dedent: 4
    :start-after: [START howto_operator_gcf_deploy]
    :end-before: [END howto_operator_gcf_deploy]

You can also create the operator without project id - project id will be retrieved
from the GCP connection used:

.. exampleinclude:: ../../../../airflow/contrib/example_dags/example_gcp_function.py
    :language: python
    :dedent: 4
    :start-after: [START howto_operator_gcf_deploy_no_project_id]
    :end-before: [END howto_operator_gcf_deploy_no_project_id]

Templating
""""""""""

.. literalinclude:: ../../../../airflow/contrib/operators/gcp_function_operator.py
    :language: python
    :dedent: 4
    :start-after: [START gcf_function_deploy_template_fields]
    :end-before: [END gcf_function_deploy_template_fields]


Troubleshooting
"""""""""""""""

If during the deploy you see an error similar to:

`"HttpError 403: Missing necessary permission iam.serviceAccounts.actAs for on resource
project-name@appspot.gserviceaccount.com. Please grant the
roles/iam.serviceAccountUser role."`

it means that your service account does not have the correct Cloud IAM permissions.

1. Assign your Service Account the Cloud Functions Developer role.
2. Grant the user the Cloud IAM Service Account User role on the Cloud Functions runtime
   service account.

The typical way of assigning Cloud IAM permissions with ``gcloud`` is
shown below. Just replace PROJECT_ID with ID of your Google Cloud Platform project
and SERVICE_ACCOUNT_EMAIL with the email ID of your service account.

.. code-block:: bash

  gcloud iam service-accounts add-iam-policy-binding \
    PROJECT_ID@appspot.gserviceaccount.com \
    --member="serviceAccount:[SERVICE_ACCOUNT_EMAIL]" \
    --role="roles/iam.serviceAccountUser"

You can also do that via the GCP Web console.

See `Adding the IAM service agent user role to the runtime service <https://cloud.google.com/functions/docs/reference/iam/roles#adding_the_iam_service_agent_user_role_to_the_runtime_service_account>`_  for details.

If the source code for your function is in Google Source Repository, make sure that
your service account has the Source Repository Viewer role so that the source code
can be downloaded if necessary.

More information
""""""""""""""""

See Google Cloud API documentation `to create a function
<https://cloud.google.com/functions/docs/reference/rest/v1/projects.locations.functions/create>`_.