我的Terraform目录结构如下：
terraform/
main.tf modules outputs.tf provider.tf variables.tf
./modules:
compute network resourcegroup
./modules/compute:
main.tf outputs.tf variables.tf
./modules/network:
main.tf outputs.tf variables.tf
./modules/resourcegroup:
main.tf outputs.tf variables.tf
资源组模块配置文件，如下所示：
目的：在此模块中，我引用了一个现有资源组，该资源组可用于创建虚拟机及其关联对象。
main.tf
data "azurerm_resource_group" "tf-rg-external" {
name = var.rg_name
}
variables.tf
variable "rg_name" {
type = string
}
网络模块
目的：我想使用来自resourcegroup模块的资源组在此模块中进行引用。这样，我可以在一个地方定义并在root和其他模块示例（例如计算，应用服务，aks等）中使用它
main.tf
# Reference existing Virtual Network
data "azurerm_virtual_network" "tf-vn" {
name = var.vnet_name
resource_group_name = module.resource_groups.external_rg_name
}
# Reference existing subnet
data "azurerm_subnet" "tf-sn" {
name = var.subnet_name
virtual_network_name = data.azurerm_virtual_network.tf-vn.name
resource_group_name = module.resource_groups.external_rg_name
}
variables.tf
# Declare env variable
variable "vnet_name" {
type = string
}
variable "subnet_name" {
type = string
}
计算模块。
目的：为compute（VM）定义所有属性。这个想法是，根模块将使用该模块来提升不同的VM角色。
main.tf
module "vm_iis" {
source = "Azure/compute/azurerm"
location = data.resourcegroup.tf-rg-external.location
vnet_subnet_id = data.network.tf-sn.id
admin_password = var.admin_password
data_sa_type = var.data_sa_type
delete_os_disk_on_termination = var.delete_os_disk_on_termination
nb_instances = var.nb_instances
nb_public_ip = var.nb_public_ip
public_ip_address_allocation = var.public_ip_address_allocation
resource_group_name = data.resourcegroup.tf-rg-external.name
.
.
.
}
variables.tf
variable "admin_password" {
type = string
}
variable "admin_username" {
type = string
}
variable "boot_diagnostics" {
type = bool
}
variable "boot_diagnostics_sa_type" {
type = string
}...
terraform 根模块。
目的：这应该利用定义的模块来创建各种大小和主机名不同的VM。
main.tf：
module "sql_vm" {
source = "./modules/compute/"
#location = data.resourcegroup.tf-rg-external.location
#vnet_subnet_id = data.network.tf-sn.id
public_ip_address_allocation = var.public_ip_address_allocation
#resource_group_name = data.resourcegroup.tf-rg-external.name
storage_account_type = var.storage_account_type
vm_hostname = var.vm_hostname
}
variables.tf：：声明 main.tf 文件中的所有变量。
注意：我故意在根模块主文件/变量文件中对变量进行了硬编码。这只是使模块之间的通信正确。理解和使用模块的正确方法。
但是，当我在根模块中运行Terraform Plan时。我收到以下错误：
Error: Reference to undeclared resource
on modules/compute/main.tf line 3, in module "vm_iis":
3: location = data.resourcegroup.tf-rg-external.location
A data resource "resourcegroup" "tf-rg-external" has not been declared in
sql_vm.
Error: Reference to undeclared resource
on modules/compute/main.tf line 4, in module "vm_iis":
4: vnet_subnet_id = data.network.tf-sn.id
A data resource "network" "tf-sn" has not been declared in sql_vm.
Error: Reference to undeclared resource
on modules/compute/main.tf line 22, in module "vm_iis":
22: resource_group_name = data.resourcegroup.tf-rg-external.name
A data resource "resourcegroup" "tf-rg-external" has not been declared in
sql_vm.
问题是什么以及如何解决？
还可以通过某个循环创建不同的（角色）vm吗？例如sql-vm，iis-vm，testvm，abcvm？将会改变的是它们的主机名和虚拟机大小。
==========
发布答案更改
==========
我更新了子网，资源组和位置的值 compute / main.tf 和 terraform / main.tf 如下：
location = module.resourcegroup.tf-rg-external-location
vnet_subnet_id = module.network.subnet-id
resource_group_name = module.resourcegroup.tf-rg-external-name
我在资源组和网络模块中的 outputs.tf 文件如下所示：
网络模块的outputs.tf
output "subnet-id" {
value = "data.network.tf-sn.id"
}
outputs.tf
output "tf-rg-external-location" {
value = data.resourcegroup.tf-rg-external.location
}
output "tf-rg-external-name" {
value = data.resourcegroup.tf-rg-external.name
}
不幸的是，我仍然遇到如下错误
Error: Unsupported argument
on main.tf line 3, in module "sql_vm":
3: location = module.resourcegroup.tf-rg-external-location
An argument named "location" is not expected here.
Error: Unsupported argument
on main.tf line 4, in module "sql_vm":
4: vnet_subnet_id = module.network.subnet-id
An argument named "vnet_subnet_id" is not expected here.
Error: Unsupported argument
on main.tf line 5, in module "sql_vm":
5: resource_group_name = module.resourcegroup.tf-rg-external-name
An argument named "resource_group_name" is not expected here.
那么，看来我们不应该在根模块中引用它们吗？
还可以在根模块的variables.tf文件中定义其变量，因为我相信您可以覆盖根模块中模块的变量的值？
如果我看起来很愚蠢，请原谅我。我正在尝试了解它在现实生活中的工作原理。
上次提交和公共回购后，错误如下
Error: Reference to undeclared module
on main.tf line 3, in module "sql_vm":
3: location = module.resourcegroup.tf-rg-external-location
No module call named "resourcegroup" is declared in the root module.
Error: Reference to undeclared module
on main.tf line 4, in module "sql_vm":
4: vnet_subnet_id = module.network.subnet-id
No module call named "network" is declared in the root module.
Error: Reference to undeclared module
on main.tf line 5, in module "sql_vm":
5: resource_group_name = module.resourcegroup.tf-rg-external-name
No module call named "resourcegroup" is declared in the root module.
Error: Reference to undeclared module
on modules/compute/main.tf line 3, in module "vm_iis":
3: location = module.resourcegroup.tf-rg-external-location
No module call named "resourcegroup" is declared in sql_vm.
Error: Reference to undeclared module
on modules/compute/main.tf line 4, in module "vm_iis":
4: vnet_subnet_id = module.network.subnet-id
No module call named "network" is declared in sql_vm.
Error: Reference to undeclared module
on modules/compute/main.tf line 5, in module "vm_iis":
5: resource_group_name = module.resourcegroup.tf-rg-external-name
No module call named "resourcegroup" is declared in sql_vm.
Error: Reference to undeclared module
on modules/network/main.tf line 5, in data "azurerm_virtual_network" "tf-vn":
5: resource_group_name = module.resource_groups.external_rg_name
No module call named "resource_groups" is declared in test2.
Error: Reference to undeclared resource
on modules/resourcegroup/outputs.tf line 2, in output "tf-rg-external-location":
2: value = data.resourcegroup.tf-rg-external.location
A data resource "resourcegroup" "tf-rg-external" has not been declared in
test1.
Error: Reference to undeclared resource
on modules/resourcegroup/outputs.tf line 5, in output "tf-rg-external-name":
5: value = data.resourcegroup.tf-rg-external.name
A data resource "resourcegroup" "tf-rg-external" has not been declared in
test1.
答案 0 :(得分：2)
浏览正在处理的仓库（https://github.com/ameyaagashe/help_me_cross/tree/d7485d2a3db339723e9c791e592b2f1dbc1f0788）。现在对我来说很有意义。
问题是，您将有关如何使用公共模块的想法与自己创建的模块混合使用。
实际上，您无需设置任何模块即可引用其他公共Terraform注册表模块。
将子模块（模块/计算，模块/网络，模块/资源组）中的所有代码移至顶部文件夹（<repo_root>/main.tf）。
例如（代码未经验证，仅供参考）
data "azurerm_resource_group" "tf-rg-external" {
name = var.rg_name
}
data "azurerm_virtual_network" "tf-vn" {
name = var.vnet_name
resource_group_name = var.rg_name
}
# Reference existing subnet
data "azurerm_subnet" "tf-sn" {
name = var.subnet_name
virtual_network_name = data.azurerm_virtual_network.tf-vn.name
resource_group_name = var.rg_name
}
module "sql_vm" {
source = "Azure/compute/azurerm"
location = data.azurerm_resource_group.tf-rg-external.location
vnet_subnet_id = data.azurerm_virtual_network.tf-vn.subnets
resource_group_name = data.azurerm_resource_group.tf-rg-external.name
admin_password = var.admin_password
admin_username = var.admin_username
boot_diagnostics = var.boot_diagnostics
boot_diagnostics_sa_type = var.boot_diagnostics_sa_type
data_disk = var.data_disk
data_disk_size_gb = var.data_disk_size_gb
data_sa_type = var.data_sa_type
delete_os_disk_on_termination = var.delete_os_disk_on_termination
enable_accelerated_networking = var.enable_accelerated_networking
# flag is_windows_image is required only when you use a custom image to spin up a VM
# is_windows_image
# flag vm_os_id is required only when you are using custom image
# you need to provide id of your custom image
# vm_os_id
nb_instances = var.nb_instances
nb_public_ip = var.nb_public_ip
public_ip_address_allocation = var.public_ip_address_allocation
storage_account_type = var.storage_account_type
vm_hostname = var.vm_hostname
vm_os_offer = var.vm_os_offer
vm_os_publisher = var.vm_os_publisher
# vm_os_simple is to be used is you do not wish to specify offer, publisher and sku
# vm_os_simple = UbuntuServer, WindowsServer, RHEL, openSUSE-Leap, CentOS, Debian, CoreOS and SLES
vm_os_sku = var.vm_os_sku
vm_os_version = var.vm_os_version
vm_size = var.vm_size
}