TerraformUsage.md

Using the Terraform CLI

Prereqs

When using the Terraform CLI, make sure you have all the necessary tools installed on your workstation.

Preparation

Set Google Cloud Authentication

Prepare a file with authentication information, as described in Authenticating Terraform to access Google Cloud.

Prepare Variable Definitions (.tfvars) File

Prepare your terraform.tfvars file, as described in Customize Input Values.

Running Terraform Commands

Initialize Terraform Environment

Initialize the Terraform environment for this project by running

terraform init

This creates a .terraform directory locally and initializes Terraform plugins and modules used in this project.

Note: terraform init only needs to be run once unless new Terraform plugins or modules were added.

Preview Cloud Resources (optional)

To preview the resources that the Terraform script will create, run

terraform plan

Create Cloud Resources

When satisfied with the plan and ready to create cloud resources, run

terraform apply -auto-approve

This command can take a few minutes to complete. Once complete, Terraform output values are written to the console.

The kubeconfig file for the cluster is being written to [prefix]-gke-kubeconfig.conf in the current directory $(pwd).

Display Outputs

Once the cloud resources have been created with apply command, to display Terraform output values, run

terraform output

Modify Cloud Resources

After provisioning the infrastructure, if further changes were to be made then add the variable and desired value to terraform.tfvars and run terrafom apply again.

Tear Down Cloud Resources

To destroy the kubernetes cluster and all related resources, run

terraform destroy

NOTE: The "destroy" action is irreversible.

Interacting with the Kubernetes cluster

Creating the cloud resources writes the kube_config output value to a file ./[prefix]-gke-kubeconfig.conf. When the Kubernetes cluster is ready, use kubectl to interact with the cluster.

Note this requires cluster_endpoint_public_access_cidrs value to be set to your local ip or CIDR range.

Example Using kubectl

export KUBECONFIG=$(pwd)/<your prefix>-gke-kubeconfig.conf
kubectl get nodes