如何在Terraform本地块中提取并重组指定键值对数据

实现方案 #

以下是在Terraform local块中完成需求的具体代码，包含输入示例、处理逻辑和输出结果：

输入JSON示例 #

{
  "regions": [
    {
      "region_id": "us-east-1",
      "zones": [
        {
          "zone_id": "us-east-1a",
          "items": [
            {
              "type": "Item1a",
              "key1": "value1a-us-east-1a",
              "key2": "value2a-us-east-1a"
            },
            {
              "type": "Item2b",
              "keyX": "valueX-us-east-1a",
              "keyY": "valueY-us-east-1a"
            }
          ]
        },
        {
          "zone_id": "us-east-1b",
          "items": [
            {
              "type": "Item1a",
              "key1": "value1a-us-east-1b",
              "key2": "value2a-us-east-1b"
            }
          ]
        }
      ]
    },
    {
      "region_id": "eu-west-1",
      "zones": [
        {
          "zone_id": "eu-west-1a",
          "items": [
            {
              "type": "Item2b",
              "keyX": "valueX-eu-west-1a",
              "keyY": "valueY-eu-west-1a"
            }
          ]
        }
      ]
    }
  ]
}

Terraform Local块代码 #

locals {
  # 扁平化所有Region-Zone下的目标Item，并补充Region/Zone标识
  filtered_items = flatten([
    for region in var.input_json.regions : [
      for zone in region.zones : [
        for item in zone.items :
        merge(item, { zone_id = zone.zone_id, region_id = region.region_id })
        if item.type == "Item1a" || item.type == "Item2b"
      ]
    ]
  ])

  # 按Item类型分组，合并不同Zone下的同类型条目
  merged_items = {
    for item in local.filtered_items :
    item.type => concat(
      lookup(local.merged_items, item.type, []),
      [omit(item, "type")]
    )
  }
}

# 输出处理后的结果
output "processed_items" {
  value = local.merged_items
}

输出结果示例 #

{
  "Item1a": [
    {
      "key1": "value1a-us-east-1a",
      "key2": "value2a-us-east-1a",
      "zone_id": "us-east-1a",
      "region_id": "us-east-1"
    },
    {
      "key1": "value1a-us-east-1b",
      "key2": "value2a-us-east-1b",
      "zone_id": "us-east-1b",
      "region_id": "us-east-1"
    }
  ],
  "Item2b": [
    {
      "keyX": "valueX-us-east-1a",
      "keyY": "valueY-us-east-1a",
      "zone_id": "us-east-1a",
      "region_id": "us-east-1"
    },
    {
      "keyX": "valueX-eu-west-1a",
      "keyY": "valueY-eu-west-1a",
      "zone_id": "eu-west-1a",
      "region_id": "eu-west-1"
    }
  ]
}

关键逻辑说明 #

• flatten()：将嵌套的Region-Zone-Item列表结构扁平化，简化后续分组操作
• merge()：为每个Item添加所属的region_id和zone_id，保留上下文信息
• 分组for表达式：以item.type为键，将同类型的Item聚合到同一列表中
• lookup()：处理分组时的初始空列表场景，避免出现键不存在的报错
• omit()：移除Item中的type字段，让输出结构更简洁

内容的提问来源于stack exchange，提问作者Doefi