IaC示例：Terraform

创建一个 NAT 模式的虚拟网络，默认的网络地址为 192.168.123.0/24，可通过变量 net_domain 修改。qTu拜客生活常识网

resource "libvirt_volume" "disk" {
  count            = length(var.vms)
  name             = "${var.vms[count.index].name}.qcow2"
  pool             = "default"
  base_volume_name = var.template_img
  base_volume_pool = var.templates_pool
}

根据变量 vms 定义的虚拟机实例，创建虚拟机的系统磁盘，基于变量 templates_pool 和 template_image 指定的模板镜像，默认也就是上面我们通过 Packer 创建的系统镜像。qTu拜客生活常识网

resource "libvirt_domain" "vm" {
  count      = length(var.vms)
  name       = var.vms[count.index].name
  autostart  = true
  qemu_agent = true
  vcpu       = lookup(var.vms[count.index], "cpu", 1)
  memory     = lookup(var.vms[count.index], "memory", 512)

...
  }
}

libvirt_domain 资源定义了需要创建的虚拟机实例，并通过 ansible provisioner 进行是初始化配置（配置静态IP地址和主机名）。qTu拜客生活常识网

resource "local_file" "ansible_hosts" {
  content = templatefile("./tpl/ansible_hosts.tpl", {
    vms        = var.vms
    subnet     = var.subnet
    gateway    = cidrhost(var.subnet, 1)
    mask       = cidrnetmask(var.subnet)
    nameserver = cidrhost(var.subnet, 1)
    user       = var.user
  })
  filename             = "../ansible/k3s_hosts"
  file_permission      = 0644
  directory_permission = 0755
}

该资源定义通过模板文件创建虚拟机实例的 Ansible Inventory 文件，便于下一步通过 Ansible 进行 K3S 集群的创建。qTu拜客生活常识网

在应用之前，我们需要配置 vms 变量，来指定我们需要的虚拟机实例信息qTu拜客生活常识网

❯ cp .k3svms.tfvars k3dcluster.auto.tfvars

vms = [
  {
    name   = "control"
    cpu    = 1
    memory = 1024
    ip     = 10
    groups = ["k3s"]
    vars   = {
      role = "server"
    }
  },
  {
    name   = "worker1"
    cpu    = 1
    memory = 1024
    ip     = 21
    groups = ["k3s"]
    vars = {
      role = "agent"
    }
  },
  {
    name   = "worker2"
    cpu    = 1
    memory = 1024
    ip     = 22
    groups = ["k3s"]
    vars = {
      role = "agent"
    }
  }
]

上面定义了3台实例，1台作为k3s集群的 server 节点，2台作为k3s集群的 role 节点，默认IP地址将会被配置为qTu拜客生活常识网

• control : 192.168.123.10
• worker1 : 192.168.123.21
• worker2 : 192.168.123.22

接下来我们将执行 Terrform 操作qTu拜客生活常识网

❯ terraform init

❯ terraform plan  

❯ terrafrom apply --auto-approve
...
Apply complete! Resources: 8 added, 0 changed, 0 destroyed.

Outputs:

vms_ip_addresses = {
  "control" = "192.168.123.10"
  "worker1" = "192.168.123.21"
  "worker2" = "192.168.123.22"
}

完成之后，3台虚拟机将会创建并运行，同时在 k3scluster/ansible/ 目录中将创建名为 k3s_hosts