This example creates a [Cloud SQL instance](https://cloud.google.com/sql) with multi-region read replicas as described in the [Cloud SQL for PostgreSQL disaster recovery](https://cloud.google.com/architecture/cloud-sql-postgres-disaster-recovery-complete-failover-fallback) article.
The solution is resilient to a regional outage. To get familiar with the procedure needed in the unfortunate case of a disaster recovery, please follow steps described in [part two](https://cloud.google.com/architecture/cloud-sql-postgres-disaster-recovery-complete-failover-fallback#phase-2) of the aforementioned article.
This example will deploy all its resources into the project defined by the `project_id` variable. Please note that we assume this project already exists. However, if you provide the appropriate values to the `project_create` variable, the project will be created as part of the deployment.
If `project_create` is left to `null`, the identity performing the deployment needs the `owner` role on the project defined by the `project_id` variable. Otherwise, the identity performing the deployment needs `resourcemanager.projectCreator` on the resource hierarchy node specified by `project_create.parent` and `billing.user` on the billing account specified by `project_create.billing_account_id`.
Configure the Terraform variables in your `terraform.tfvars` file. You need to specify at least the `project_id` and `prefix` variables. See [`terraform.tfvars.sample`](terraform.tfvars.sample) as starting point.
| [prefix](variables.tf#L40) | Unique prefix used for resource names. Not used for project if 'project_create' is null. | <code>string</code> | ✓ | |
| [project_id](variables.tf#L54) | Project id, references existing project if `project_create` is null. | <code>string</code> | ✓ | |
| [cmek_encryption](variables.tf#L17) | Flag to enable CMEK on GCP resources created. | <code>bool</code> | | <code>false</code> |
| [data_eng_principals](variables.tf#L23) | Groups with Service Account Token creator role on service accounts in IAM format, only user supported on CloudSQL, eg 'user@domain.com'. | <code>list(string)</code> | | <code>[]</code> |
| [project_create](variables.tf#L45) | Provide values if project creation is needed, uses existing project if null. Parent is in 'folders/nnn' or 'organizations/nnn' format. | <codetitle="object({ billing_account_id = string parent = string })">object({…})</code> | | <code>null</code> |
| [regions](variables.tf#L59) | Map of instance_name => location where instances will be deployed. | <code>map(string)</code> | | <codetitle="{ primary = "europe-west1" replica = "europe-west3" }">{…}</code> |