Application should be provisioned using Terraform. For each application that requires resources in AWS, create a Terraform root module for each account in which it will be deployed.
infra/ applications/ example/ sandbox/ production/
To ensure that staging and production match, you can encapsulate stateful resources into a module:
infra/ applications/ example/ modules/ state/
You can then this module to provision resources in each account. You can also use the Flightdeck application-config module to set up the namespace, service account, secrets, and role bindings in your cluster:
# applications/example/sandbox/main.tf module "staging" { source = "../modules/state" cluster_names = [data.aws_eks_cluster.sandbox_v1.name] environment = "staging" s3_bucket = "example-staging-activestorage" redis_sidekiq_name = "example-staging-sidekiq-redis-orange" redis_sidekiq_node_type = "cache.t4g.micro" postgres_identifier = "example-staging-strawberry" postgres_instance_class = "db.t4g.small" } module "staging_sandbox_v1" { providers = { kubernetes = kubernetes.sandbox_v1 } source = "github.com/thoughtbot/flightdeck//aws/application-config" namespace = module.staging.namespace secrets_manager_secrets = module.staging.secrets_manager_secrets pod_service_account = module.staging.service_account_name pod_iam_role = module.staging.pod_role_arn } data "aws_eks_cluster" "sandbox_v1" { name = "example-sandbox-v1" }