PostgreSQL Operator
Terraform module for Kubernetes

The PostgreSQL operator provisions and configures a PostgreSQL database cluster on top of Kubernetes. PostgreSQL is a powerful, open-source object-relational database system.

This Terraform module provisions PostgreSQL Operator on Kubernetes. It fully integrates the Kubernetes resources into the Terraform workflow and allows configuring PostgreSQL Operator using native Terraform syntax.

The PostgreSQL Operator module is continuously updated and tested when new upstream versions are released.

TL;DR:

Call the module once per desired target cluster.
The provider alias you pass into the module determines the cluster.
Customize the Kubernetes resources per environment using Terraform syntax.

Use the module

To provision the PostgreSQL Operator Terraform module on a Kubernetes cluster, call the module, set source and version, and pass an aliased kustomization provider into the module. The provider configuration determines what cluster the Kuberneters resources are provisioned on. Framework documentation includes a complete example of how the kubeconfig output of a cluster module can be used to configure a kustomization provider alias.

module "eks_zero_postgresql" {
  providers = {
    kustomization = kustomization.eks_zero
  }

  source  = "kbst.xyz/catalog/postgresql/kustomization"
  version = "1.7.1-kbst.2"
}

module "aks_zero_postgresql" {
  providers = {
    kustomization = kustomization.aks_zero
  }

  source  = "kbst.xyz/catalog/postgresql/kustomization"
  version = "1.7.1-kbst.2"
}

module "gke_zero_postgresql" {
  providers = {
    kustomization = kustomization.gke_zero
  }

  source  = "kbst.xyz/catalog/postgresql/kustomization"
  version = "1.7.1-kbst.2"
}

Customize resources

All Kubestack cluster service modules support the same module attributes and per environment configuration. The module configuration is a Kustomization set in the per environment configuration map following Kubestack's inheritance model.

This example overwrites the metadata.namespace of all Kubernetes resources provisioned by the PostgreSQL Operator module using a Terraform variable.

module "example_postgresql" {
  providers = {
    kustomization = kustomization.example
  }

  source  = "kbst.xyz/catalog/postgresql/kustomization"
  version = "1.7.1-kbst.2"

  configuration = {
    apps = {
      namespace = var.example_postgresql_namespace
    }

    ops = {}

    loc = {}
  }
}

Full documentation how to customize a module's Kubernetes resources is available in the cluster service module configuration section of the framework documentation.

Usage

Once the operator has been deployed to the Kubernetes cluster, you can use it to provision and operate one or more database clusters by creating a custom object of the operator's custom resource.

PostgreSQL Custom Object

Below is an example of a minimal PostgreSQL custom object to instruct the operator to provision a database cluster.

To get started, put the example below into a file called postgresql.yaml and add it to your application's manifests. Then apply the manifests including the postgresql.yaml as usual.

apiVersion: "acid.zalan.do/v1"
kind: postgresql
metadata:
  name: acid-minimal-cluster
  namespace: default
spec:
  postgresql:
    version: "10"
  teamId: "ACID"
  volume:
    size: 1Gi
  numberOfInstances: 2
  users:
    # admin user
    admin:
    - superuser
    # application user
    app_user: []

  databases:
    # db_name: user_name
    app_db: app_user

Configuring your cluster

Make sure to configure name and namespace and the users and databases according to your application's requirements.

You can find additional information on these parameters and additional options in the upstream project's documentation.