Terraform Code - GCP Infrastructure

This directory holds the Terraform code that enables the deployment of a GKE cluster and Postgres CloudSQL. These modules create a layered setup that helps with setting up infrastructure that is predictable, easy to manage, reproducible, and easy to extend.

NOTE: This may cost money if you are out of credits.

Requirements

• terraform

Environment Setup

To setup an environment, create a directory for the environment with the modules you wish to deploy. Example dev and prd environment has been created. Each module within an environment will follow a basic structure with 3 files:

• backend.tf - Specifies the bucket where th terraform state file is stored remotely.
• main.tf - References the module to deploy and any required variables (each module has a README specifying the required/optional variables).
• provider.tf - Specifies google provider variables (project, zone, region).

An example main.tf file for the psql module is shown below:

module "psql" {
    source = "../../../tf-modules/psql"

    environment = "dev"
    db_name     = "psql"
}

output "module" {
    value   = module.psql
    sensitive = true
}

Once the files have been setup for each module, within the environment module created run the following terraform commands to spin up the GCP infrastructure (N.B. Don't forget to setup your project and remote bucket):

terraform init
terraform plan # (skip if you want to apply immediately)
terraform apply # (--auto-approve if you're feeling adventures)

Once you have used your infrastructure and don't need it anymore, don't forget to destroy it (so that you don't incur unwanted costs):

terraform destroy # (--auto-approve if you're feeling confident)

Deployment Sequence

As the modules are setup in a layered setup the deployment sequence is important. For the current solution the deployment sequence should start with the deployment of the base module and after the gke and psql modules in parallel.

Module documentation

• Each module subdirectory has its own README.md file containing basic information on the module.

• Inputs and Outputs are automatically documented using pre-commit hook in these README.md files.

  • To automatically create the documentation you need to install the hooks as described below and add the following text within the README.md file:

  <!-- BEGINNING OF PRE-COMMIT-TERRAFORM DOCS HOOK -->
  <!-- END OF PRE-COMMIT-TERRAFORM DOCS HOOK -->

Hooks

Install pre-commit and terraform-docs (on MacOS, Homebrew has formulae for both). You can install the pre-commit hooks by running pre-commit install.

Possible Improvements

• Create multiple users with varying degrees of permissions to connect to the Postgres Database.
• Deploy k8s configmaps and secrets via terraform that reference information to the Postgres Database (host, users and passwords, etc).
• Deploy via GitHub Actions