Second round of updates for the Backstage quickstart

[bgood]

The major updates in this round include:

• Code to build and deploy the container images
• Documentation to guide readers on how to update Cloud SQL and deploy the Kubernetes manifests
• Templatization of the Kubernetes manifests and application configs

[aburhan]

@bgood

Running terraform apply resulted in the follow issue.

1. APIs that need to be enabled:

• sqladmin.googleapis.com (Cloud SQL Admin API)
• compute.googleapis.com (Compute Engine API)
• iam.googleapis.com (Identity and Access Management API)
• iap.googleapis.com (Cloud Identity-Aware Proxy API)
• cloudresourcemanager.googleapis.com (Cloud Resource Manager API)
• autoscaling.googleapis.com (Autoscaling API)
• containerfilesystem.googleapis.com (Container Filesystem API)

2. Deprecation warning (FYI)
   "Warning: Deprecated Resource
   │
   │ with google_iap_brand.backstageIapBrand,
   │ on iap.tf line 15, in resource "google_iap_brand" "backstageIapBrand":
   │ 15: resource "google_iap_brand" "backstageIapBrand" {
   │
   │ after July 2025, the google_iap_brand Terraform resource will no longer function as intended due to the deprecation of the IAP OAuth Admin API"

   this says it must be setup in the console...Deprecation of IAP OAuth Admin API hashicorp/terraform-provider-google#21378

3. Readme step 6 has a typo

   gcloud container clusters get-credentials backstage-qs --region us-central1 --dns-endpoint   # this should be--dns-endpoint

[bgood]

@aburhan Thank you!

1. The list of APIs that get enabled are in variables.tf and they are enabled in project.tf. IAM was missing but I've added it to the list. The others were there but because they are enabled async, there are race conditions in the Terraform, I haven't tracked down yet. Figured we could take care of that in a different PR.
2. Good catch, let's discuss.
3. Good catch, fixed.

[bgood]

@aburhan For your second point of feedback. I added a gcloud command to create the brand and then calculate the brand name in Terraform, so we should be good now for that deprecation. @gushob21 thanks for the pointers.

[aburhan]

@bgood

I got it up and running there just one required update and one nit update.

issue	fix/error
Instruction “4. Set the configuration variables" instruction doesn't isn't setting the YOUR_IAP_SUPPORT_EMAIL	Add: sed -i "s/YOUR_IAP_SUPPORT_EMAIL/${IAP_SUPPORT_EMAIL}/g" ${BACKSTAGE_QS_BASE_DIR}/backstage-qs.auto.tfvars
Initial run of the terraform results in errors. Rerunning the terraform usually resolves	Add a note in the instructions to run terraform again if they experience the issue or add it depends_on clause in terraform.

[gushob21]

I have not run the architecture , assuming that it works, made just one comment :)