terraform-google-cloud-sql-saver

Terraform module to simplify cost savings of Cloud SQL instances on GCP.

View on Terraform Registry

Purpose

This module is intended to reduce the cost of using GCP's Cloud SQL service by scheduling your instances to start and stop. This is a practice that would typically be implemented in a non-production environment. Running your instances in this manner can save you ~75% of the cost to run an instance per week. The cost savings estimate assumes an instance running 9 hours a day, 5 days a week compared to 24/7.

Note: Backups can only be performed while an instance is running so the backup window needs to be adjusted accordingly.

Inspired by a blog post from Google, the module was developed with reusability in mind by leveraging Terraform. It also goes a step beyond that of the blog post to handle:

• Multiple start/stop schedules
• Multiple instances

Architecture

1. Cloud Scheduler job sends start/stop message to Pub/Sub topic.
2. Pub/Sub topic message publish event triggers the Cloud Function.
3. Cloud Function sends start/stop API call to Cloud SQL instance(s).

Requirements

• Terraform >= 0.13.0
• terraform-provider-google plugin v4.2.x

Usage

module "cloud-sql-saver" {
  source     = "mscribellito/cloud-sql-saver/google"
  project_id = "your-project-id"
  region     = "us-east1"
  schedule =  {
    "8am-5pm-est" = {
      start     = "0 8 * * 1-5"
      stop      = "0 17 * * 1-5"
      instances = ["acme-db-1", "acme-db-2"]
      time_zone = null # set to null to use time zone from inputs
    }
    "8am-5pm-mst" = {
      start     = "0 8 * * 1-5"
      stop      = "0 17 * * 1-5"
      instances = ["acme-db-3", "acme-db-4"]
      time_zone = "America/Denver"
    }
  }
  create_app_engine = false # set to false if an App Engine application is already created in your project
}

Inputs

Name	Description	Type	Default	Required
project_id	The project ID to manage the resources.	string	n/a	yes
region	The region of the resources.	string	"us-east1"	no
schedule	Start/stop schedule.	map(object({ start = string, stop = string, instances = list(string), time_zone = string }))	{}	no
time_zone	Default time zone name from the tz database for scheduled jobs.	string	"America/New_York"	no
create_app_engine	Whether App Engine application should be created.	bool	true	no
gcp_services	List of GCP Services to enable.	list(string)	See variables.tf	no

Outputs

N/A

Changelog

• 1.1.2

  • Fix issue where bucket name is not unique.

• 1.1.1

  • Fix issue where default time zone is not configured if a time zone is not specified.

• 1.1.0

  • Add least privilege service account for Cloud Function.

• 1.0.0

  • Release stable version.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

License

MIT