Terraform with Google Kubernetes Engine (GKE)

Deploying a GKE K8s cluster using Terraform

Prepare the environment

Download Terraform binary:

wget https://releases.hashicorp.com/terraform/1.0.4/terraform_1.0.4_linux_amd64.zip

unzip terraform_1.0.4_linux_amd64.zip -d /usr/local/bin

Verify you can run terraform:

terraform -v

Download Google Cloud SDK:

curl https://sdk.cloud.google.com | bash
Move to /usr/local/bin and/or set your PATH if needed

Or via your package manager, i.e for Ubuntu/Debian:

Add the Cloud SDK distribution URI as a package source

echo "deb http://packages.cloud.google.com/apt cloud-sdk main" | sudo tee -a /etc/apt/sources.list.d/google-cloud-sdk.list

Import the Google Cloud Platform public key

curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -

Update the package list and install the Cloud SDK

sudo apt-get update && sudo apt-get install google-cloud-sdk

Run gcloud init and follow instructions
Run gcloud auth application-default login and follow instructions
Enable the following API's for the compute and container services:

gcloud services enable compute.googleapis.com
gcloud services enable container.googleapis.com

You can now list your GKE clusters by running the following:

gcloud container clusters list

Provision a cluster via gcloud CLI for testing:

You can very easily create a GKE cluster by running:
gcloud container clusters create \
--machine-type e2-micro \
--num-nodes 1 \
--zone us-east1-a \
--cluster-version latest \
testk8s-cluster

Creating cluster testk8s-cluster in us-east1-a... Cluster is being deployed... Cluster is being health-checked...

When the cluster is created you will find a kubeconfig file the the directory you ran the command from.
Install kubectl if you haven't alraeady:
sudo apt-get update && sudo apt-get install -y apt-transport-https ca-certificates curl

echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt-get update && sudo apt-get install -y kubectl

Run kubectl get nodes
Run gcloud container clusters update to change settings in the cluster such as the number of nodes.
Destroy the cluster by running:
gcloud container clusters delete testk8s-cluster --zone us-east1-a
NOTE: be careful not to run this on a production cluster for obvious reasons!

Provision GKE K8s via Terraform

Grab the terraform files in the repository
Amend the tf files in the repo to match your project, region, credentials file, etc
Run terraform init, this should initialize terraform and generate the state file
Run terraform validate to make sure the config has no errors
Run terraform plan which is essentially a dry-run and will provide a summary of all the changes that will be made and resources that will be created
Now terraform apply, this will create the cluster environment, enter the project-id when prompted and hit yes to confirm you want to continue. Go grab a coffee, this may take a while.
Inspect your directry tree structure, you will now see the state and kubeconfig files have been generated.
Run export KUBECONFIG="${PWD}/kubeconfig-prod"
Then run: kubectl get pods --all-namespaces
Now you can create deployments in the cluster and apply them like any other kubernetes:

kubectl create -f deployment.yaml

Run terraform destroy to destroy the entire cluster. NOTE: be careful not to run this in production!

Expose your pods via a LoadBalancer

NOTE: this will incur charges!
kubectl create -f svc-loadbalancer.yaml

kubectl get services

Routing traffic via an Ingress

kubectl create -f ingress.yaml

kubectl describe ingress <pod>

kubectl example commands:

see: https://kubernetes.io/docs/reference/kubectl/cheatsheet/

kubectl get pods -o wide
kubectl get ingress
kubectl get services
kubectl get nodes
kubectl logs <pod>
kubectl exec --stdin --tty <pod> -- /bin/bash
kubectl describe pods
kubectl describe nodes
kubectl create -f <yaml>
kubectl delete -f <yaml>

gcloud commands:

gcloud compute forwarding-rules list \ --filter description~hello-gke-k8s \ --format \ "table[box](name,IPAddress,target.segment(-2):label=TARGET_TYPE)"

binbashblog/Terraform-GCP-GKE-K8s_Cluster_files