CODEWITHSUNDEEP
terraform
XciD
XciD

Reputation: 2605

Convert a list to map and merge values terraform

I'm trying to convert a list of items into a map. The key will match a key in the item and the value should create a list of appends to the list if the key already exist.

Maybe an example will be more understable

variable "list" {
  type = list(map(string))
  default = [
    { a : "a", k : "k1" },
    { a : "b", k : "k1" },
    { a : "c", k : "k1" },
    { a : "d", k : "k2" },
    { a : "e", k : "k2" }
  ]
}
    
// Output wanted
// {
//  "k1" : [{a: "a"}, {a: "b"}, {a: "c"}],
//  "k2" : [{a: "d"}, {a: "e"}]
// }

Thank you

Upvotes: 3

Views: 3575

Answers (1)

Marcin
Marcin

Reputation: 238975

You can have a look at the following:

variable "list" {
  type = list(map(string))
  default = [
    { a : "a", k : "k1" },
    { a : "b", k : "k1" },
    { a : "c", k : "k1" },
    { a : "d", k : "k2" },
    { a : "e", k : "k2" }
  ]
}

output "test" {

  value = {for item in var.list:
            item["k"] => {a = item["a"]}...
          }
}

The above code uses three dots operator and it produces:

test = {
  "k1" = [
    {
      "a" = "a"
    },
    {
      "a" = "b"
    },
    {
      "a" = "c"
    },
  ]
  "k2" = [
    {
      "a" = "d"
    },
    {
      "a" = "e"
    },
  ]
}

Upvotes: 4

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