terraform - 引用 Terraform 中的其他模块资源

Question

我的 Terraform Cloud git 项目中有这样的层次结构:

├── aws
│   ├── flavors
│   │   └── main.tf
│   ├── main.tf
│   ├── security-rules
│   │   └── sec-rule1
│   │       └── main.tf
│   └── vms
│   │   └── vm1
│   │       └── main.tf
└── main.tf

所有主要 main.tf 文件都包含带有子文件夹的模块定义:

/main.tf:

terraform {
  required_version = "~> 0.12.0"

  backend "remote" {
    hostname = "app.terraform.io"    
    organization = "foo"

    workspaces {
      name = "bar"
    }
  }
  required_providers {
    openstack = "~> 1.24.0"
  }
}

module "aws" {
  source = "./aws"
}

/aws/main.tf:

module "security-rules" {
  source = "./security-rules"
}

module "flavors" {
  source = "./flavors"
}

module "vms" {
  source = "./vms"
}

/aws/security-rules/main-tf:

module "sec-rule1" {
  source = "./sec-rule1"
}

/aws/vms/main-tf:

module "vm1" {
  source = "./vm1"
}

然后我定义了这个安全规则。

/aws/security-rules/sec-rule1/main-tf:

resource "openstack_compute_secgroup_v2" "sec-rule1" {
  name        = "sec-rule1"
  description = "Allow web port"
  rule {
    from_port   = 80
    to_port     = 80
    ip_protocol = "tcp"
    cidr        = "0.0.0.0/0"
  }
  lifecycle {
            prevent_destroy = false
    }
}

而且我想从一个或多个虚拟机引用它，但我不知道如何通过资源 ID(或名称)进行引用。我使用普通名称而不是引用。

/aws/vms/vm1/main-tf:

resource "openstack_blockstorage_volume_v3" "vm1_volume" {
  name     = "vm1_volume"
  size     = 30
  image_id = "foo-bar"
}

resource "openstack_compute_instance_v2" "vm1_instance" {
  name        = "vm1_instance"
  flavor_name = "foo-bar"
  key_pair    = "foo-bar keypair"
  image_name  = "Ubuntu Server 18.04 LTS Bionic"
  block_device {
    uuid                  = "${openstack_blockstorage_volume_v3.vm1_volume.id}"
    source_type           = "volume"
    destination_type      = "volume"
    boot_index            = 0
    delete_on_termination = false
  }

  network {
    name = "SEG-tenant-net"
  }

  security_groups = ["default", "sec-rule1"]
  config_drive    = true
}

resource "openstack_networking_floatingip_v2" "vm1_fip" {
  pool = "foo-bar"
}

resource "openstack_compute_floatingip_associate_v2" "vm1_fip" {
  floating_ip = "${openstack_networking_floatingip_v2.vm1_fip.address}"
  instance_id = "${openstack_compute_instance_v2.vm1_instance.id}"
}

我想使用按名称或 ID 引用的安全规则(以及更多内容)，因为这样会更加一致。除了当我创建一个新的安全规则，同时创建一个 VM 时，Terraform OpenStack 提供者计划它没有错误，但是在应用它时，会产生错误，因为 VM 首先创建并且没有找到尚未创建的新的安全规则。

我该怎么做？

Answer 1

您应该为 sec-rule1 和 security-rules/ 模块输出 sec_rule_allow_web_name，然后设置 的输出>security-rules/ 模块作为 vm1 和 vms 模块的输入。通过这种方式，您可以保持 vm1 模块与 security_rules 输出的依赖关系，该输出称为 Dependency Inversion。 .

# ./security-rules/<example>/outputs.tf

output "sec_rule_allow_web_name" {
  value = "<some-resource-to-output>"
}

# ./vms/variables.tf

variable "security_rule_name" {}

前提是在正确的模块中定义了输出和输入。

# /aws/main.tf

# best practice to use underscores instead of dashes in names
# so security-roles/ directory is now called security_rules
module "security_rules" {
  source = "./security-rules"
}

module "flavors" {
  source = "./flavors"
}

module "vms" {
  source = "./vms"

  security_rule_name = module.security_rules.sec_rule_allow_web_name
}