Maintain the production GKE cluster using Terraform

[NimJay]

Background

• We would like to update the production GKE cluster because of b/350893565 (Google-internal link).
• This is also a follow-up to pull-request (PR) 2418 where we started maintaining the staging/PR deployments' GKE cluster via Terraform.

Change Summary

• This change:
  • introduces Terraform for a new GKE cluster to be used for production
  • introduces Terraform for a static IP address to be used for cymbal-shops.retail.cymbal.dev. (We'll need to update the DNS later — before deleting the current production GKE cluster.)
  • updates .github/terraform/README.md.

Testing Procedure

• I have not terraform apply-ed yet.
• If you'd like you can test the terraform plan:

git checkout nimjay-terraform-prod-cluster # Checkout this branch
cd .github/terraform/
terraform init
terraform plan -var project_id=online-boutique-ci

• You should see 2 things being planned for creation: the cluster and the static IP address.

After merging

After merging this, we will need to:

1. terraform apply to create the new GKE cluster (and new static IP address).
2. Deploy the production resources (in [/.github/release-cluster]
   (https://github.com/GoogleCloudPlatform/microservices-demo/tree/main/.github/release-cluster)) to the new cluster.
3. Update the DNS record for cymbal-shops.retail.cymbal.dev to point to the new static IP address. See cl/600467717.
4. Troubleshoot any issues. I'm sure we'll run into issues with HTTPS.
5. Update GitHub Actions to use new cluster and docs about creating a new release.
6. Delete the old production cluster.
7. Update go/sample-app-ci.

[github-actions]

🚲 PR staged at http://104.154.165.160

[github-actions]

🚲 PR staged at http://104.154.165.160

[github-actions]

🚲 PR staged at http://104.154.165.160

[github-actions]

🚲 PR staged at http://104.154.165.160