Creating a default ROSA (classic architecture) cluster using Terraform

$ mkdir terraform-cluster && cd terraform-cluster

$ export RHCS_TOKEN=<your_offline_token>

$ cat<<-EOF>main.tf
#
# Copyright (c) 2023 Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = ">= 4.20.0"
    }
    rhcs = {
      version = ">= 1.6.2"
      source  = "terraform-redhat/rhcs"
    }
  }
}

# Export token using the RHCS_TOKEN environment variable
provider "rhcs" {}

provider "aws" {
  region = var.aws_region
  ignore_tags {
    key_prefixes = ["kubernetes.io/"]
  }
  default_tags {
    tags = var.default_aws_tags
  }
}

data "aws_availability_zones" "available" {}

locals {
  # The default setting creates 3 availability zones. Set to "false" to create a single availability zones.
  region_azs = var.multi_az ? slice([for zone in data.aws_availability_zones.available.names : format("%s", zone)], 0, 3) : slice([for zone in data.aws_availability_zones.available.names : format("%s", zone)], 0, 1)
}

resource "random_string" "random_name" {
  length  = 6
  special = false
  upper   = false
}

locals {
  path                 = coalesce(var.path, "/")
  worker_node_replicas = try(var.worker_node_replicas, var.multi_az ? 3 : 2)
  # If cluster_name is not null, use that, otherwise generate a random cluster name
  cluster_name = coalesce(var.cluster_name, "rosa-\${random_string.random_name.result}")
}

# The network validator requires an additional 60 seconds to validate Terraform clusters.
resource "time_sleep" "wait_60_seconds" {
  count = var.create_vpc ? 1 : 0
  depends_on = [module.vpc]
  create_duration = "60s"
}

module "rosa-classic" {
  source                 = "terraform-redhat/rosa-classic/rhcs"
  version                = "1.5.0"
  cluster_name           = local.cluster_name
  openshift_version      = var.openshift_version
  account_role_prefix    = local.cluster_name
  operator_role_prefix   = local.cluster_name
  replicas               = local.worker_node_replicas
  aws_availability_zones = local.region_azs
  create_oidc            = true
  private                = var.private_cluster
  aws_private_link       = var.private_cluster
  aws_subnet_ids         = var.create_vpc ? var.private_cluster ? module.vpc[0].private_subnets : concat(module.vpc[0].public_subnets, module.vpc[0].private_subnets) : var.aws_subnet_ids
  multi_az               = var.multi_az
  create_account_roles   = true
  create_operator_roles  = true

  depends_on = [time_sleep.wait_60_seconds]
}
EOF

$ cat<<-EOF>variables.tf
#
# Copyright (c) 2023 Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
variable "openshift_version" {
  type        = string
  default     = "4.14.20"
  description = "Desired version of OpenShift for the cluster, for example '4.14.20'. If version is greater than the currently running version, an upgrade will be scheduled."
}

variable "create_vpc" {
  type        = bool
  description = "If you would like to create a new VPC, set this value to 'true'. If you do not want to create a new VPC, set this value to 'false'."
}

# ROSA Cluster info
variable "cluster_name" {
  default     = null
  type        = string
  description = "The name of the ROSA cluster to create"
}

variable "additional_tags" {
  default = {
    Terraform   = "true"
    Environment = "dev"
  }
  description = "Additional AWS resource tags"
  type        = map(string)
}

variable "path" {
  description = "(Optional) The arn path for the account/operator roles as well as their policies."
  type        = string
  default     = null
}

variable "multi_az" {
  type        = bool
  description = "Multi AZ Cluster for High Availability"
  default     = true
}

variable "worker_node_replicas" {
  default     = 3
  description = "Number of worker nodes to provision. Single zone clusters need at least 2 nodes, multizone clusters need at least 3 nodes"
  type        = number
}

variable "aws_subnet_ids" {
  type        = list(any)
  description = "A list of either the public or public + private subnet IDs to use for the cluster blocks to use for the cluster"
  default     = ["subnet-01234567890abcdef", "subnet-01234567890abcdef", "subnet-01234567890abcdef"]
}

variable "private_cluster" {
  type        = bool
  description = "If you want to create a private cluster, set this value to 'true'. If you want a publicly available cluster, set this value to 'false'."
}

#VPC Info
variable "vpc_name" {
  type        = string
  description = "VPC Name"
  default     = "tf-qs-vpc"
}

variable "vpc_cidr_block" {
  type        = string
  description = "value of the CIDR block to use for the VPC"
  default     = "10.0.0.0/16"
}

variable "private_subnet_cidrs" {
  type        = list(any)
  description = "The CIDR blocks to use for the private subnets"
  default     = ["10.0.1.0/24", "10.0.2.0/24", "10.0.3.0/24"]
}

variable "public_subnet_cidrs" {
  type        = list(any)
  description = "The CIDR blocks to use for the public subnets"
  default     = ["10.0.101.0/24", "10.0.102.0/24", "10.0.103.0/24"]
}

variable "single_nat_gateway" {
  type        = bool
  description = "Single NAT or per NAT for subnet"
  default     = false
}

#AWS Info
variable "aws_region" {
  type    = string
  default = "us-east-2"
}

variable "default_aws_tags" {
  type        = map(string)
  description = "Default tags for AWS"
  default     = {}
}
EOF

$ cat<<-EOF>vpc.tf
#
# Copyright (c) 2023 Red Hat, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
module "vpc" {
  source  = "terraform-aws-modules/vpc/aws"
  version = "5.1.2"

  count = var.create_vpc ? 1 : 0
  name  = var.vpc_name
  cidr  = var.vpc_cidr_block

  azs             = local.region_azs
  private_subnets = var.private_subnet_cidrs
  public_subnets  = var.public_subnet_cidrs

  enable_nat_gateway   = true
  single_nat_gateway   = var.single_nat_gateway
  enable_dns_hostnames = true
  enable_dns_support   = true

  tags = var.additional_tags
}
EOF

$ terraform init

$ terraform validate

Success! The configuration is valid.

$ terraform apply

var.create_vpc
  If you would like to create a new VPC, set this value to 'true'. If you do not want to create a new VPC, set this value to 'false'.

  Enter a value:

var.private_cluster
  If you want to create a private cluster, set this value to 'true'. If you want a publicly available cluster, set this value to 'false'.

  Enter a value:

Plan: 74 to add, 0 to change, 0 to destroy.

Do you want to perform these actions?
  Terraform will perform the actions described above.
  Only 'yes' will be accepted to approve.

  Enter a value: yes

$ rosa list clusters

ID                                NAME          STATE  TOPOLOGY
27c3snjsupa9obua74ba8se5kcj11269  rosa-tf-demo  ready  Classic (STS)

$ rosa list account-roles

I: Fetching account roles
ROLE NAME                                   ROLE TYPE      ROLE ARN                                                           OPENSHIFT VERSION  AWS Managed
ROSA-demo-ControlPlane-Role                 Control plane  arn:aws:iam::<ID>:role/ROSA-demo-ControlPlane-Role                 4.14               No
ROSA-demo-Installer-Role                    Installer      arn:aws:iam::<ID>:role/ROSA-demo-Installer-Role                    4.14               No
ROSA-demo-Support-Role                      Support        arn:aws:iam::<ID>:role/ROSA-demo-Support-Role                      4.14               No
ROSA-demo-Worker-Role                       Worker         arn:aws:iam::<ID>:role/ROSA-demo-Worker-Role                       4.14               No

$ rosa list operator-roles

I: Fetching operator roles
ROLE PREFIX    AMOUNT IN BUNDLE
rosa-demo      6

$ terraform destroy

var.create_vpc
  If you would like to create a new VPC, set this value to 'true.' If you do not want to create a new VPC, set this value to 'false.'

  Enter a value:

var.private_cluster
  If you want to create a private cluster, set this value to 'true.' If you want a publicly available cluster, set this value to 'false.'

  Enter a value:

Plan: 0 to add, 0 to change, 74 to destroy.

Do you really want to destroy all resources?
  Terraform will destroy all your managed infrastructure, as shown above.
  There is no undo. Only 'yes' will be accepted to confirm.

  Enter a value: yes

$ rosa list clusters

I: No clusters available

$ rosa list account-roles

I: Fetching account roles
I: No account roles available

$ rosa list operator-roles

I: Fetching operator roles
I: No operator roles available