In the previous part we created our GKE Autopilot cluster. In this part we will configure the Cloud SQL Instance.

The following resources will be created:

• A highly available private Cloud SQL MySQL Instance
• A database and a user
• An automatic internal IP range for private connection
• A private connection to GCP services

Cloud SQL

• The Cloud SQL Instance used is a MySQL database server
• The Multiples zones option is enabled to ensure high-availability
• The Instance is not publicly accessible and it's reachable only using its private IP
• The authentication is done via IAM
• Automated backup is enabled
• We create a database and a user for later

Create a terraform file infra/plan/cloud-sql.tf

resource "random_string" "db_name_suffix" {
  length  = 4
  special = false
  upper   = false
}

resource "google_sql_database_instance" "mysql" {

  # Instance info
  name             = "mysql-private-${random_string.db_name_suffix.result}"
  region           = var.region
  database_version = var.mysql_database_version

  settings {

    # Region and zonal availability
    availability_type = var.mysql_availability_type
    location_preference {
      zone = var.mysql_location_preference
    }

    # Machine Type
    tier              = var.mysql_machine_type

    # Storage
    disk_size         = var.mysql_default_disk_size

    # Connections
    ip_configuration {
      ipv4_enabled        = false
      private_network     = google_compute_network.custom.id
    }

    # Backups
    backup_configuration {
      binary_log_enabled = true
      enabled = true
      start_time = "06:00"
    }
  }
  depends_on = [
    google_service_networking_connection.private-vpc-connection
  ]
}

data "google_secret_manager_secret_version" "wordpress-admin-user-password" {
  secret = "wordpress-admin-user-password"
}

resource "google_sql_database" "wordpress" {
  name     = "wordpress"
  instance = google_sql_database_instance.mysql.name
}

resource "google_sql_user" "wordpress" {
  name = "wordpress"
  instance = google_sql_database_instance.mysql.name
  password = data.google_secret_manager_secret_version.wordpress-admin-user-password.secret_data
}

Add the following outputs

output "cloud-sql-connection-name" {
  value = google_sql_database_instance.mysql.connection_name
}

output "cloud-sql-instance-name" {
  value = "mysql-private-${random_string.db_name_suffix.result}"
}

Private connection

We need to configure private services access to allocate an IP address range and create a private service connection. This will allow resources in the Web subnet to connect to the Cloud SQL instance.

Complete the file infra/plan/vpc.tf with the following resources:

resource "google_compute_global_address" "private-ip-peering" {
  name          = "google-managed-services-custom"
  purpose       = "VPC_PEERING"
  address_type  = "INTERNAL"
  prefix_length = 24
  network       = google_compute_network.custom.id
}

resource "google_service_networking_connection" "private-vpc-connection" {
  network = google_compute_network.custom.id
  service = "servicenetworking.googleapis.com"
  reserved_peering_ranges = [
    google_compute_global_address.private-ip-peering.name
  ]
}

Complete the file infra/plan/variable.tf:

variable "region" {
  type = string
  default = "europe-west1"
}

variable "mysql_location_preference" {
  type = string
  default = "europe-west1-b"
}

variable "mysql_machine_type" {
  type = string
  default = "db-n1-standard-2"
}

variable "mysql_database_version" {
  type = string
  default = "MYSQL_8_0"
}

variable "mysql_default_disk_size" {
  type = string
  default = "100"
}

variable "mysql_availability_type" {
  type = string
  default = "REGIONAL"
}

Before applying the changes, we need to create the secret of the user password:

gcloud services enable secretmanager.googleapis.com --project $PROJECT_ID

gcloud beta secrets create wordpress-admin-user-password --locations $REGION --replication-policy user-managed
echo -n "changeme" | gcloud beta secrets versions add wordpress-admin-user-password --data-file=-

Let's deploy our Cloud SQL instance

cd infra/plan

gcloud services enable sqladmin.googleapis.com --project $PROJECT_ID

terraform apply

Let's check if all the resources have been created and are working correctly:

Cloud SQL instance

Peering connection

Private connection

Conclusion

Our Cloud SQL instance is now available. In the last part, we'll establish a connection between a container deployed in GKE cluster and a database created in an Cloud SQL instance.