Managing GCP Composer Kubernetes cluster using Terraform - kubernetes

Question

I've created a GCP Composer environment using Terraform:
terraform {
required_providers {
google = {
source = "hashicorp/google"
version = "3.5.0"
}
}
}
provider "google" {
credentials = file("my_key.json")
project = "my_project_id"
region = "us-east1"
zone = "us-east1-b"
}
resource "google_composer_environment" "my_composer_id" {
name = "my_composer_name"
region = "us-east1"
config {
node_count = 3
node_config {
zone = "us-east1-b"
machine_type = "n1-standard-1"
}
}
}
Composer also automatically creates a Kubernetes Engine cluster. Such cluster has a single node pool called default-pool. I'd like to create a new node pool inside the cluster created by Composer. Something like this:
resource "google_container_node_pool" "my_node_pool_id" {
name = "my_node_pool_name"
location = "us-east1"
cluster = ????
node_count = 0
node_config {
preemptible = true
machine_type = "n1-standard-1"
}
autoscaling {
min_node_count = 0
max_node_count = 3
}
}
However, as I didn't create the cluster in the Terraform file (as it was automatically created by Composer), I don't have the reference to it.

Answer 1

Cluster name can be accessed via the key gke_cluster available in the config section of your Cloud Composer environment :
resource "google_container_node_pool" "my_node_pool_id" {
name = "my_node_pool_name"
location = "us-east1-b"
cluster = element(
split("/",
lookup(
google_composer_environment.my_composer_id.config[0],
"gke_cluster"
)
),
5
)
// ...
}
The 5th element corresponds to the name of the GKE cluster.