如何在Terraform中合并两个JSON输出为指定结构？解决值覆盖问题

问题场景 #

现有两个JSON结构的输出，需合并为包含ansible_playbook与external_ip字段的目标结构，解决合并时的值覆盖或冗余键问题：

现有输出1（含Playbook配置） #

"test_01": {
  "app-server": {
    "ansible_playbook": "playbook.yml"
  },
  "db-server": {
    "ansible_playbook": "playbook-02.yml"
  }
}

现有输出2（含IP配置） #

"test_02": {
  "app-server": {
    "external_ip": "app-ip"
  },
  "db-server": {
    "external_ip": "db-ip"
  }
}

期望目标输出 #

"test_01": {
  "app-server": {
    "ansible_playbook": "playbook.yml",
    "external_ip": "app-ip"
  },
  "db-server": {
    "ansible_playbook": "playbook-02.yml",
    "external_ip": "db-ip"
  }
}

解决方案 #

利用Terraform的merge函数结合for_each遍历节点，精准合并对应服务器的字段：

示例配置 #

假设输入数据来自本地变量（若为资源输出，替换为对应资源引用即可）：

locals {
  # 输入1：Playbook配置数据
  playbook_config = {
    "test_01" = {
      "app-server" = {
        "ansible_playbook" = "playbook.yml"
      },
      "db-server" = {
        "ansible_playbook" = "playbook-02.yml"
      }
    }
  }

  # 输入2：IP配置数据
  ip_config = {
    "test_02" = {
      "app-server" = {
        "external_ip" = "app-ip"
      },
      "db-server" = {
        "external_ip" = "db-ip"
      }
    }
  }

  # 核心合并逻辑
  merged_result = {
    "test_01" = {
      # 遍历所有服务器节点，逐个合并对应字段
      for server_name, _ in local.playbook_config.test_01 :
      server_name => merge(
        local.playbook_config.test_01[server_name],
        local.ip_config.test_02[server_name]
      )
    }
  }
}

# 输出合并后的结果
output "final_merged_output" {
  value = local.merged_result
}

关键说明 #

• for_each遍历第一个输入中的服务器节点，确保每个节点都被单独处理，避免顶层键冲突
• merge函数针对单个服务器节点合并字段，保证ansible_playbook和external_ip不会互相覆盖
• 若输入来自资源输出（比如模块输出、数据源结果），只需将local.playbook_config和local.ip_config替换为对应的资源引用路径即可

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