Example terraform for gcp nodes with network config.

Create a simple network with some nodes, for use with Rancher's Custom Cluster feature, where nodes are pre-provisioned. Then one can pass other configurations/automations to install a Kubernetes distribution like RKE2 or K3S.

• Requies valid gcp credentials in .env file in local working directory
• Requires variables configuration to match project details

## example .env
export GOOGLE_APPLICATION_CREDENTIALS="$PWD/project-name-hexidentity.json"
export GCLOUD_PROJECT=$(jq -r '.project_id' $GOOGLE_APPLICATION_CREDENTIALS)
export GCLOUD_REGION="northamerica-northeast2"

• Requires ssh key in local dir, *.pub added to gitignore
• uses NVME scratch disk for Longhorn experimentation
• sets up trusted-services (ssl, ssh, vpn) and trusted-nets (local & remote)

I had a reference architecture used in AWS for a while, and wondered how to quickly emulate the same in GCP given proper pre-existing access.

• Updated to include variables, ipv6 optional configuration, pg backend, and latest gcp tofu provider.