terraform {
  required_providers {
    libvirt = {
      source  = "dmacvicar/libvirt"
      version = ">= 0.6.2"
    }
  }
  backend "pg" {
    conn_str = "postgres://terraform_local@localhost/terraform_local?sslmode=disable"
  }
}

provider "libvirt" {
  uri = var.libvirt_provider_uri
}

resource "libvirt_volume" "base_volume" {
  name   = "vm_base_volume"
  source = var.vm_image_source
}

resource "libvirt_volume" "control_plane_volume" {
  name           = "control_plane_${count.index}.qcow2"
  base_volume_id = libvirt_volume.base_volume.id
  count          = var.control_plane_count
}

resource "libvirt_volume" "node_volume" {
  name           = "worker_${count.index}.qcow2"
  base_volume_id = libvirt_volume.base_volume.id
  count          = var.node_count
}

resource "libvirt_volume" "load_balancer_volume" {
  name           = "load_balancer_${count.index}.qcow2"
  base_volume_id = libvirt_volume.base_volume.id
  count          = var.load_balancer_count
}

# Public ssh key for vm (it is directly injected in cloud-init configuration) #
data "template_file" "public_ssh_key" {
  template = file("${var.vm_ssh_private_key}.pub")
}

# Cloud-init configuration template #
data "template_file" "cloud_init_tpl" {
  template = file("templates/cloud_init.cfg.tpl")

  vars = {
    ssh_public_key = data.template_file.public_ssh_key.rendered
  }
}

# Cloud-init configuration template for load balancer #
data "template_file" "cloud_init_load_balancer_tpl" {
  template = file("templates/cloud_init_load_balancer.cfg.tpl")

  vars = {
    ssh_public_key = data.template_file.public_ssh_key.rendered
  }
}

# Creates cloud-init configuration file from template for node #
resource "local_file" "cloud_init_node_file" {
  content  = data.template_file.cloud_init_tpl.rendered
  filename = "config/cloud_init.cfg"
}

# Creates cloud-init configuration file from template for load balancer #
resource "local_file" "cloud_init_load_balancer_file" {
  content  = data.template_file.cloud_init_load_balancer_tpl.rendered
  filename = "config/cloud_init_load_balancer.cfg"
}

data "template_file" "network_config" {
  template = file("${path.module}/cloud-init/network_config.yaml")
}

resource "libvirt_cloudinit_disk" "cloud_init_k8s" {
  name      = "cloud_init_k8s.iso"
  user_data = data.template_file.cloud_init_tpl.rendered
  network_config = data.template_file.network_config.rendered
}

resource "libvirt_cloudinit_disk" "cloud_init_load_balancer" {
  name      = "cloud_init_load_balancer.iso"
  user_data = data.template_file.cloud_init_load_balancer_tpl.rendered
  network_config = data.template_file.network_config.rendered
}

resource "libvirt_network" "vm_net" {
  name      = "vm_net"
  mode      = "bridge"
  bridge    = "virbr0"
  autostart = true
}

resource "libvirt_domain" "load_balancer" {
  name        = "load_balancer${count.index}"
  description = "Kubernetes Load Balancer ${count.index}"
  cpu = {
    mode = "host-passthrough"
  }
  vcpu      = 1
  memory    = "1024"
  cloudinit = libvirt_cloudinit_disk.cloud_init_load_balancer.id
  disk {
    volume_id = libvirt_volume.load_balancer_volume[count.index].id
  }
  qemu_agent = true
  autostart  = true
  running    = true
  count      = var.load_balancer_count

  network_interface {
    network_id     = libvirt_network.vm_net.id
    hostname       = "load-balancer${count.index}"
    mac            = "AA:BB:CC:11:33:0${count.index}"
    wait_for_lease = true
  }
}

resource "libvirt_domain" "control_plane" {
  name        = "controller${count.index}"
  description = "Kubernetes control plane ${count.index}"
  cpu = {
    mode = "host-passthrough"
  }
  vcpu      = 2
  memory    = "2048"
  cloudinit = libvirt_cloudinit_disk.cloud_init_k8s.id
  disk {
    volume_id = libvirt_volume.control_plane_volume[count.index].id
  }
  network_interface {
    network_id     = libvirt_network.vm_net.id
    hostname       = "controller${count.index}"
    mac            = "AA:BB:CC:11:11:0${count.index}"
    wait_for_lease = true
  }
  qemu_agent = true
  autostart  = true
  running    = true
  count      = var.control_plane_count

}

resource "libvirt_domain" "node" {
  name        = "worker${count.index}"
  description = "Kubernetes Node ${count.index}"
  cpu = {
    mode = "host-passthrough"
  }
  vcpu      = 2
  memory    = "2048"
  cloudinit = libvirt_cloudinit_disk.cloud_init_k8s.id
  disk {
    volume_id = libvirt_volume.node_volume[count.index].id
  }
  qemu_agent = true
  autostart  = true
  running    = true
  count      = var.node_count

  network_interface {
    network_id     = libvirt_network.vm_net.id
    hostname       = "worker${count.index}"
    mac            = "AA:BB:CC:11:22:0${count.index}"
    wait_for_lease = true
  }
}

output "load_balancer_ip_addresses" {
  value = libvirt_domain.load_balancer.*.network_interface.0.addresses
}

output "control_plane_ip_addresses" {
  value = libvirt_domain.control_plane.*.network_interface.0.addresses
}

output "node_ip_addresses" {
  value = libvirt_domain.node.*.network_interface.0.addresses
}