如何将子模块的additional_tags传递至Terragrunt根配置的provider块？

需求目标 #

从模块目录（如./non-production/eu-west-1/dev/eks-vpc/terragrunt.hcl）关联的_envcommon/[模块名].hcl文件中读取additional_tags，并与根目录terragrunt.hcl中的通用标签合并，最终注入到generate "provider"块的AWS默认标签中。

当前目录结构 #

├── README.md
├── _envcommon
│   └── eks-vpc.hcl
├── non-production
│   ├── account.hcl
│   └── eu-west-3
│       ├── dev
│       │   ├── eks-vpc
│       │   │   └── terragrunt.hcl
│       │   └── env.hcl
│       ├── region.hcl
└── terragrunt.hcl

解决方案 #

1. 修正模块目录的terragrunt.hcl关联路径 #

确保模块指向正确的_envcommon配置文件（以eks-vpc模块为例）：

# ./non-production/eu-west-1/dev/eks-vpc/terragrunt.hcl
include "root" {
  path   = find_in_parent_folders()
  expose = true
}

# 关联对应模块的envcommon配置
include "envcommon"{
    path = "${get_parent_terragrunt_dir()}/_envcommon/eks-vpc.hcl"
    expose = true
}

terraform {
  source = "${include.envcommon.locals.base_url}?ref=v1.0.0"
}

inputs = {
    # 其他输入值
}

2. 修改根目录terragrunt.hcl实现标签合并 #

在根配置中动态读取当前模块对应的_envcommon配置，合并通用标签与模块专属标签：

# ./terragrunt.hcl
locals {
  account_vs     = read_terragrunt_config(find_in_parent_folders("account.hcl"))
  environment_vs = read_terragrunt_config(find_in_parent_folders("env.hcl"))

  account_id         = local.account_vs.locals.aws_account_id
  profile            = "<aws_profile_name>"
  region             = "eu-west-1"

  common_tags = {
      env            = local.environment_vs.locals.environment
      controlledBy   = "terraform"
  }

  # 动态获取当前模块名称，读取对应envcommon配置
  module_name        = basename(get_terragrunt_dir())
  envcommon_config   = read_terragrunt_config("${get_parent_terragrunt_dir()}/_envcommon/${local.module_name}.hcl")
  additional_tags    = lookup(local.envcommon_config.locals, "additional_tags", {}) # 兼容无additional_tags的情况

  # 合并通用标签与模块专属标签
  tags = merge(local.common_tags, local.additional_tags)
}

generate "provider" {
  path      = "provider.tf"
  if_exists = "skip"
  contents  = <<EOF
provider "aws" {
  region = "${local.region}"
  profile = "${local.profile}"
  allowed_account_ids = ["${local.account_id}"]
  default_tags {
    tags = ${jsonencode(local.tags)}
  }
}
EOF
}

remote_state {
  # 远程状态配置
}

3. _envcommon/eks-vpc.hcl保持原有配置 #

# ./envcommon/eks-vpc.hcl
locals {
  additional_tags={
    "Criticality"       = "critical"
    "Supporting:Tools"  = true
  }
  base_url = "你的模块仓库地址" # 补充实际地址
}

说明 #

• 该方案支持多模块场景，每个模块可关联_envcommon下对应的配置文件，实现按模块注入不同的默认标签。
• 使用lookup函数兼容部分模块无additional_tags的情况，避免执行报错。

内容的提问来源于stack exchange，提问作者joebegborg07