Tạo Cluster Kubernetes với Terraform

Hướng dẫn này sẽ hướng dẫn bạn qua quá trình tạo Cluster Kubernetes với Terraform.

Điều kiện tiên quyết

• Terraform đã được cài đặt trên máy của bạn.
• Tài khoản Vietnix Cloud.

Các bước tạo Cluster Kubernetes với Terraform

1. Tạo file cấu hình Terraform.

File Cấu hình Terraform

# main.tf
terraform {
  required_providers {
    openstack = {
      source  = "terraform-provider-openstack/openstack"
      version = ">= 1.45.0"
    }
  }
  required_version = ">= 1.6.0"
}

# auth provider
provider "openstack" {
  auth_url    = "https://auth.vietnix.cloud:5000/v3"
  user_name   = "your-username"
  password    = "your-password"
  tenant_name = "your-tenant-name"
  domain_id   = "your-domain-id"
}

# Create SSH keypair for Kubernetes cluster
resource "openstack_compute_keypair_v2" "terraform_k8s_keypair" {
  name       = "terraform_k8s_key"
  public_key = file("${var.ssh_key_file}.pub")
}

# Create network for Kubernetes cluster
resource "openstack_networking_network_v2" "terraform_k8s_network" {
  name        = "terraform_k8s_network"
  description = "Network for Terraform Kubernetes cluster"
}

# Create subnet for Kubernetes cluster
resource "openstack_networking_subnet_v2" "terraform_k8s_subnet" {
  name            = "terraform_k8s_subnet"
  network_id      = openstack_networking_network_v2.terraform_k8s_network.id
  cidr            = "10.0.0.0/24"
  gateway_ip      = "10.0.0.1"
  ip_version      = 4
  dns_nameservers = ["8.8.8.8", "8.8.4.4"]
}

# Create router for Kubernetes cluster
resource "openstack_networking_router_v2" "terraform_k8s_router" {
  name                = "terraform_k8s_router"
  external_network_id = var.external_network_id
  enable_snat         = true
}

# Connect router to subnet
resource "openstack_networking_router_interface_v2" "terraform_router_interface" {
  router_id = openstack_networking_router_v2.terraform_k8s_router.id
  subnet_id = openstack_networking_subnet_v2.terraform_k8s_subnet.id
}

# Create cluster template
resource "openstack_containerinfra_clustertemplate_v1" "terraform_k8s_template" {
  name                  = "terraform_k8s_template"
  coe                  = "kubernetes"
  image                = var.k8s_image_id
  flavor               = var.flavor_name
  external_network_id  = var.external_network_id
  server_type          = "vm"
  volume_driver        = "cinder"
  docker_storage_driver = "overlay2"
  docker_volume_size   = var.docker_volume_size
  network_driver       = "cilium"
  master_lb_enabled    = false
  floating_ip_enabled  = true
  fixed_network        = openstack_networking_network_v2.terraform_k8s_network.id
  fixed_subnet         = openstack_networking_subnet_v2.terraform_k8s_subnet.id
}

# Create Kubernetes cluster
resource "openstack_containerinfra_cluster_v1" "terraform_k8s_cluster" {
  name                = "terraform_k8s_cluster"
  cluster_template_id = openstack_containerinfra_clustertemplate_v1.terraform_k8s_template.id
  keypair            = openstack_compute_keypair_v2.terraform_k8s_keypair.name
  master_count       = 1
  node_count         = 2
  master_flavor      = "medium.2c.4g"
  flavor             = "small.1c.2g"
  create_timeout     = 60
  docker_volume_size = 10
  
  labels = {
    boot_volume_type         = "nvmer3"
    docker_volume_type       = "nvmer3"
    boot_volume_size         = "20"
    etcd_lb_disabled         = "true"
    heat_container_agent_tag = "5.3.11"
    cloud_provider_tag       = "v1.31.1"
    cloud_provider_enabled   = "true"
    cinder_csi_plugin_tag    = "v1.31.1"
    csi_snapshotter_tag      = "v8.0.1"
    csi_attacher_tag         = "v4.6.1"
    flannel_tag              = "v0.11.0-amd64"
    cinder_csi_enabled       = "true"
    availability_zone        = "nova"
    use_podman               = "true"
    etcd_tag                 = "v3.5.13"
    cgroup_driver            = "systemd"
    octavia_api_lb_flavor    = ""
    octavia_default_flavor   = ""
    auto_scaling_enabled     = "True"
    cluster_upgrade_method   = "replace"
    network_driver           = "cilium"
    kube_tag                 = "v1.31.2"
    kube_version             = "v1.31.2"
    hyperkube_image          = "docker.io/virtuozzo/hci-binary-hyperkube"
    autoscaler_tag           = "1.31.0"
    coredns_tag              = "1.11.3"
    k8s_keystone_auth_tag    = "v1.31.1"
    cilium_tag               = "v1.16.3"
    container_runtime        = "containerd"
    monitoring_enabled       = "False"
    minion_floating_ip_disabled = "True"
    cilium_routing_mode      = "native"
  }
}

File Biến

Tạo file variables.tf để định nghĩa các biến của bạn:

# variables.tf
variable "ssh_key_file" {
  description = "Path to the SSH private key file"
  type        = string
  default     = "~/.ssh/id_rsa"
}

variable "external_network_id" {
  description = "ID of the external network"
  type        = string
}

variable "k8s_image_id" {
  description = "ID of the image to use for Kubernetes nodes"
  type        = string
}

variable "flavor_name" {
  description = "Name of the flavor for the cluster template"
  type        = string
  default     = "small.1c.2g"
}

variable "docker_volume_size" {
  description = "Size of the Docker volume in GB"
  type        = number
  default     = 10
}

variable "master_count" {
  description = "Number of master nodes"
  type        = number
  default     = 1
}

variable "node_count" {
  description = "Number of worker nodes"
  type        = number
  default     = 2
}

variable "master_flavor" {
  description = "Flavor for master nodes"
  type        = string
  default     = "medium.2c.4g"
}

variable "worker_flavor" {
  description = "Flavor for worker nodes"
  type        = string
  default     = "small.1c.2g"
}

Outputs File

Tạo file outputs.tf để hiển thị thông tin quan trọng:

# outputs.tf
output "k8s_cluster_id" {
  description = "ID of the created Kubernetes cluster"
  value       = openstack_containerinfra_cluster_v1.terraform_k8s_cluster.id
}

output "k8s_cluster_name" {
  description = "Name of the created Kubernetes cluster"
  value       = openstack_containerinfra_cluster_v1.terraform_k8s_cluster.name
}

output "k8s_cluster_status" {
  description = "Status of the Kubernetes cluster"
  value       = openstack_containerinfra_cluster_v1.terraform_k8s_cluster.status
}

output "k8s_cluster_api_address" {
  description = "API address of the Kubernetes cluster"
  value       = openstack_containerinfra_cluster_v1.terraform_k8s_cluster.api_address
}

output "k8s_cluster_master_addresses" {
  description = "Master node addresses"
  value       = openstack_containerinfra_cluster_v1.terraform_k8s_cluster.master_addresses
}

output "k8s_cluster_node_addresses" {
  description = "Worker node addresses"
  value       = openstack_containerinfra_cluster_v1.terraform_k8s_cluster.node_addresses
}

output "k8s_cluster_kubeconfig" {
  description = "Kubeconfig content for the cluster"
  value       = openstack_containerinfra_cluster_v1.terraform_k8s_cluster.kubeconfig
  sensitive   = true
}

2. Chạy terraform init để khởi tạo cấu hình Terraform.

terraform init

3. Chạy terraform plan để lập kế hoạch cấu hình Terraform.

terraform plan

mẹo

Bạn có thể thêm các biến vào lệnh plan để xem kế hoạch với các giá trị cụ thể.

terraform plan -var="ssh_key_file=~/.ssh/id_rsa" -var="external_network_id=your-external-network-id" -var="k8s_image_id=your-k8s-image-id" -var="flavor_name=small.1c.2g" -var="docker_volume_size=10" -var="master_count=1" -var="node_count=2"

4. Chạy terraform apply để tạo cluster Kubernetes.

terraform apply

mẹo

Bạn có thể thêm các biến vào lệnh apply để tạo cluster với các giá trị cụ thể.

terraform apply -var="ssh_key_file=~/.ssh/id_rsa" -var="external_network_id=your-external-network-id" -var="k8s_image_id=your-k8s-image-id" -var="flavor_name=small.1c.2g" -var="docker_volume_size=10" -var="master_count=1" -var="node_count=2"

5. Chạy terraform destroy để xóa cluster Kubernetes.

terraform destroy

Xác minh Cluster Kubernetes

Sau khi cluster Kubernetes được tạo, bạn có thể xác minh cluster bằng cách:

1. Lấy kubeconfig

# Lấy nội dung kubeconfig
terraform output k8s_cluster_kubeconfig

# Lưu kubeconfig vào file
terraform output -raw k8s_cluster_kubeconfig > kubeconfig
export KUBECONFIG=./kubeconfig

2. Kiểm tra trạng thái cluster

kubectl cluster-info
kubectl get nodes
kubectl get pods --all-namespaces

3. Triển khai ứng dụng thử nghiệm

kubectl run nginx --image=nginx --port=80
kubectl expose pod nginx --type=NodePort --port=80
kubectl get services

Các Hướng dẫn Hữu ích Khác

• Tạo VM với Terraform