如何使用 Cloudformation 模板中的变量作为 terraform 中 "Data source" 的特征

Question

在terraform中，我们可以使用data source获取存在的资源详情。

但是在 cloudformation 中，如果资源不是由 cloudformation 模板创建的，我找不到任何方法来引用它，除非我对值进行硬编码，例如真实的 vpc id。

有什么建议吗？

Answer 1

您可以这样做的一种方法是使用参数（例如 AWS::EC2::VPC::Id 表示 vpc ID）。在创建堆栈时，这将列出您在其中创建堆栈的区域中的所有现有 vpc。目前，此类参数仅限于少数几个，例如卷、子网、sg，但将来可能会出现更多。尽管目前在 cloudformation 中还没有任何与 terraform 数据源完全相同的东西。您也可以使用 cloudformation 宏来设计一些东西，但这会有点令人费解。

Answer 2

最后我用cloudformation做了一个vpc栈，它从aws cli获取参数输入并输出vpc id，subnet id等

此cloudformation模板只有一个空资源（因为cloudformation模板中没有资源会报错）

Description: >
  This template deploys a VPC, with a pair of public and private subnets spread
  across two Availabilty Zones. It deploys an Internet Gateway, with a default
  route on the public subnets. It deploys a pair of NAT Gateways (one in each AZ),
  and default routes for them in the private subnets.
Parameters:

  EnvironmentName:
    Description: An environment name that will be prefixed to resource names
    Type: String

  VPC:
    Description: Please enter the VPC ID
    Type: String

  VpcCIDR:
    Description: Please enter the IP range (CIDR notation) for this VPC
    Type: String

  PublicSubnet1:
    Description: Please enter the IP range (CIDR notation) for the public subnet in the first Availability Zone
    Type: String

  PublicSubnet2:
    Description: Please enter the IP range (CIDR notation) for the public subnet in the second Availability Zone
    Type: String

  PrivateSubnet1:
    Description: Please enter the IP range (CIDR notation) for the private subnet in the first Availability Zone
    Type: String

  PrivateSubnet2:
    Description: Please enter the IP range (CIDR notation) for the private subnet in the second Availability Zone
    Type: String

Conditions:
  HasNot: !Equals [ 'true', 'false' ]

Resources:
  NullResource:
    Type: 'Custom::NullResource'
    Condition: HasNot

Outputs:

  VPC:
    Description: A reference to the created VPC
    Value: !Ref VPC
    Export:
      Name: !Sub "${EnvironmentName}:VPC"

  PublicSubnet1:
    Description: A reference to the public subnet in the 1st Availability Zone
    Value: !Ref PublicSubnet1
    Export:
      Name: !Sub "${EnvironmentName}:PublicSubnet1"

  PublicSubnet2:
    Description: A reference to the public subnet in the 2nd Availability Zone
    Value: !Ref PublicSubnet2
    Export:
      Name: !Sub "${EnvironmentName}:PublicSubnet2"

  PrivateSubnet1:
    Description: A reference to the private subnet in the 1st Availability Zone
    Value: !Ref PrivateSubnet1
    Export:
      Name: !Sub "${EnvironmentName}:PrivateSubnet1"

  PrivateSubnet2:
    Description: A reference to the private subnet in the 2nd Availability Zone
    Value: !Ref PrivateSubnet2
    Export:
      Name: !Sub "${EnvironmentName}:PrivateSubnet2"

  VpcCIDR:
    Description: VPC CIDR
    Value: !Ref VpcCIDR
    Export:
      Name: !Sub "${EnvironmentName}:VpcCIDR"

我运行一个bash脚本来收集这些数据（你可以写javascript，pytyon或任何其他语言来收集这些数据），将它们作为参数提供给上面的cloudformation .

#!/bin/bash

set -ex

DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null && pwd )"

# collect the vpc details.
# you can run aws cli or any aws sdk to collect them.
source ../common_function.sh
echo ${VPC_ID}

aws --profile "${AWS_PROFILE}" --region "${AWS_DEFAULT_REGION}" \
    cloudformation deploy \
    --stack-name "${ENVIRONMENT_NAME}-vpc" \
    --capabilities CAPABILITY_IAM \
    --template-file "${DIR}/vpc.yaml" \
    --parameter-overrides \
    EnvironmentName="${ENVIRONMENT_NAME}" \
    VPC="${VPC_ID}" \
    VpcCIDR="${VPC_CIDR}" \
    PublicSubnet1="${PUBLIC_SUBNET_ID_1}" \
    PublicSubnet2="${PUBLIC_SUBNET_ID_2}" \
    PrivateSubnet1="${PRIVATE_SUBNET_ID_1}" \
    PrivateSubnet2="${PRIVATE_SUBNET_ID_2}"

在 cfn 堆栈之上部署后，您可以在其他 cfn 堆栈中引用这些输出变量。

VpcId:
    'Fn::ImportValue': !Sub "${EnvironmentName}:VPC"

如何使用 Cloudformation 模板中的变量作为 terraform 中 "Data source" 的特征

How to work with variables in Cloudformation template as the feature of "Data source" in terraform

amazon-cloudformation

terraform

terraform-provider-aws