Terraform Google Scheduled Functions Module

This modules makes it easy to set up a scheduled job to trigger events/run functions.

Compatibility

This module is meant for use with Terraform 0.12. If you haven't upgraded and need a Terraform 0.11.x-compatible version of this module, the last released version intended for Terraform 0.11.x is v0.4.1.

Usage

You can go to the examples folder, however the usage of the module could be like this in your own main.tf file:

module "scheduled-function" {
  source  = "terraform-google-modules/scheduled-function/google"
  version = "0.1.0"
  project_id   = "<PROJECT ID>"
  job_name="<NAME_OF_JOB>"
  schedule="<CRON_SYNTAX_SCHEDULE"
  function_entry_point="<NAME_OF_FUNCTION>"
  function_source_directory="<DIRECTORY_OF_FUNCTION_SOURCE>"
  function_name="<RESOURCE_NAMES>"
  region="<REGION>"
}

Then perform the following commands on the root folder:

• terraform init to get the plugins
• terraform plan to see the infrastructure plan
• terraform apply to apply the infrastructure build
• terraform destroy to destroy the built infrastructure

Inputs

Name	Description	Type	Default	Required
bucket_name	The name to apply to the bucket. Will default to a string of -scheduled-function-XXXX> with XXXX being random characters.	string	""	no
function_available_memory_mb	The amount of memory in megabytes allotted for the function to use.	string	"256"	no
function_description	The description of the function.	string	"Processes log export events provided through a Pub/Sub topic subscription."	no
function_entry_point	The name of a method in the function source which will be invoked when the function is executed.	string	n/a	yes
function_environment_variables	A set of key/value environment variable pairs to assign to the function.	map	<map>	no
function_event_trigger_failure_policy_retry	A toggle to determine if the function should be retried on failure.	string	"false"	no
function_labels	A set of key/value label pairs to assign to the function.	map	<map>	no
function_name	The name to apply to the function	string	n/a	yes
function_runtime	The runtime in which the function will be executed.	string	"nodejs6"	no
function_source_archive_bucket_labels	A set of key/value label pairs to assign to the function source archive bucket.	map	<map>	no
function_source_directory	The contents of this directory will be archived and used as the function source.	string	n/a	yes
function_timeout_s	The amount of time in seconds allotted for the execution of the function.	string	"60"	no
job_description	Addition text to describet the job	string	""	no
job_name	The name of the scheduled job to run	string	n/a	yes
job_schedule	The job frequency, in cron syntax	string	"*/2 * * * *"	no
message_data	The data to send in the topic message.	string	"dGVzdA=="	no
project_id	The ID of the project where this VPC will be created	string	n/a	yes
region	The region in which resources will be applied.	string	n/a	yes
topic_name	Name of pubsub topic connecting the scheduled job and the function	string	"test-topic"	no
time_zone	The timezone to be used in scheduler job	string	"Etc/UTC"	no

Outputs

Name	Description
name	The name of the job created

Requirements

Terraform plugins

• Terraform 0.12.x
• terraform-provider-google plugin v2.1

App Engine

Note that this module requires App Engine being configured in the specified project/region. This is because Google Cloud Scheduler is dependent on the project being configured with App Engine. Refer to the Google Cloud Scheduler documentation for more information on the App Engine dependency.

The recommended way to create projects with App Engine enabled is via the Project Factory module. There is an example of how to create the project within that module

Configure a Service Account

In order to execute this module you must have a Service Account with the following roles.

• roles/storage.admin
• roles/pubsub.editor
• roles/cloudscheduler.admin
• roles/cloudfunctions.developer
• roles/iam.serviceAccountUser

Enable API's

In order to operate with the Service Account you must activate the following API on the project where the Service Account was created:

• Cloud Scheduler API - cloudscheduler.googleapis.com
• Cloud PubSub API - pubsub.googleapis.com
• Cloud Functions API - cloudfunctions.googleapis.com

Install

Terraform

Be sure you have the correct Terraform version (0.12.x), you can choose the binary here:

• https://releases.hashicorp.com/terraform/

Testing and documentation generation

Requirements

• docker
• terraform-docs 0.6.0

Integration test

Terraform integration tests

It is recommended to to run the integration tests via docker. To do so, run make test_integration_docker. In containers, this will

• Perform terraform init command
• Perform terraform get command
• Perform terraform validate command
• Perform terraform apply -auto-approve command and check that it has created the appropriate resources
• Perform terraform destroy -force command and check that it has destroyed the appropriate resources

Autogeneration of documentation from .tf files

Run

make generate_docs

Linting

The makefile in this project will lint or sometimes just format any shell, Python, golang, Terraform, or Dockerfiles. The linters will only be run if the makefile finds files with the appropriate file extension.

All of the linter checks are in the default make target, so you just have to run

make -s

The -s is for 'silent'. Successful output looks like this

Running shellcheck
Running flake8
Running gofmt
Running terraform validate
Running hadolint on Dockerfiles
Test passed - Verified all file Apache 2 headers

The linters are as follows:

• Shell - shellcheck. Can be found in homebrew
• Python - flake8. Can be installed with 'pip install flake8'
• Golang - gofmt. gofmt comes with the standard golang installation. golang is a compiled language so there is no standard linter.
• Terraform - terraform has a built-in linter in the 'terraform validate' command.
• Dockerfiles - hadolint. Can be found in homebrew