Terraform:合并列表映射并合并来自重复键的列表

Question

我有这样的东西

locals {
  roles = [
    {
      role = "roles/admin"
      members = ["user:user@example.com"]
    },
    {
      role = "roles/viewer"
      members = ["user:user2@example.com"]
    }
  ]
}

我希望我的模块能够导出它们自己的角色列表，例如

roles = [
    {
      role = "roles/viewer"
      members = ["user:newperson@example.com"]
    }
]

然后能够将这些东西合并在一起得到

locals {
  roles = [
    {
      role = "roles/admin"
      members = ["user:user@example.com"]
    },
    {
      role = "roles/viewer"
      members = ["user:user2@example.com", "user:newperson@example.com"]
    }
  ]
}

我知道如果我将所有内容都存储为 map ，我可以合并这些 map ，只要没有重复的键，它就可以正常工作。但在这种情况下，我明确希望能够拥有重复的键，这样一个模块就不需要关心任何其他模块。

更新 我可以通过这样做来实现这一点:

roles = distinct(flatten([
    for rm in local.role_maps : [
      for role, members in rm :
      {
        role = role
        members = sort(distinct(flatten([
          for m in local.role_maps :
          m[role] if lookup(m, role, null) != null
        ])))
      }
    ]
  ]))

Answer 1

这似乎是一个很好的应用 for expression使用 ... 分组修饰符，它可以通过按键分组生成列表映射。

variable "custom_roles" {
  type = list(object({
    role    = string
    members = list(string)
  })
}

locals {
  default_roles = [
    {
      role    = "roles/admin"
      members = ["user:user@example.com"]
    },
    {
      role    = "roles/viewer"
      members = ["user:user2@example.com"]
    }
  ]
  all_roles = concat(
    local.default_roles,
    var.custom_roles,
  )

  # First we'll project the inputs so that we have one
  # role/member pair per element.
  flat_roles = flatten([
    for r in locals.all_roles : [
      for m in r.members : {
        role   = r.role
        member = m
      }
    ]
  ])

  # Then we can use that flattened list to produce a map
  # grouped by unique role key.
  merged_roles = {
    for k, v in local.all_roles : k => v...
  }

  # Finally, if the list-of-objects representation was
  # important then we can recover it by projecting that
  # merged_roles map back into the list shape.
  merged_roles_list = tolist([
    for role, members in local.merged_roles : {
      role    = role
      members = tolist(members)
    }
  ])
}

在上面，local.merged_roles 是一个列表映射，如下所示:

{
  "roles/admin"  = ["user:user@example.com"]
  "roles/viewer" = ["user:user2@example.com", "user:newperson@example.com"]
}

您可以直接使用该 map ，但以防万一对象列表形式很重要，我包含了 local.merged_roles_list，它应该与您提出问题的结构相匹配。