Convert list to map with index in Terraform

Question

I would like to convert a simple list of string in terraform to a map with the keys as indexes.

I want to go from something like this:

locals {
  keycloak_secret = [
    "account-console",
    "admin-cli",
    "broker",
    "internal",
    "realm-management",
    "security-admin-console",
  ]
}

To something like

map({0:"account-console", 1:"admin-cli"}, ...)

My goal is to take advantage of the new functionality of terraform 0.13 to use loop over map on terraform module.

I didn't find any solution, may something help me, thank you.

Is there a reason you need the index here? Would you not be better off with just converting the list into a set so you can loop over it with `for_each`? — ydaetskcoR, Aug 14 '20 at 15:03
@ydaetskcoR I didn't know it was possible. Do you have an exemple please ? I'm always trying to learn more. — severin.julien, Aug 15 '20 at 10:14

score 19 · Accepted Answer · answered Aug 14 '20 at 08:39

19

If I understand correctly, you want to convert your list into map. If so, then you can do this as follows:

locals {
  keycloak_secret_map  = {for idx, val in local.keycloak_secret: idx => val}  
}

which produces:

{
  "0" = "account-console"
  "1" = "admin-cli"
  "2" = "broker"
  "3" = "internal"
  "4" = "realm-management"
  "5" = "security-admin-console"
}

answered Aug 14 '20 at 08:39

Marcin

215,873
14
235
294

1

Thanks @Marcin, that is exactly what I wanted. I've accepted your answer :) – severin.julien Aug 14 '20 at 08:56

score 1 · Answer 2 · answered Aug 14 '20 at 08:58

1

I've come up with another solution, which is uglier than @Marcin 's answer.

locals = {
    keycloak_secret_map = for secret_name in local.keycloak_secret : index(local.keycloak_secret, secret_name) => secret_name
}

Which gives

{
  0 = "account-console"
  1 = "admin-cli"
  2 = "broker"
  3 = "internal"
  4 = "realm-management"
  5 = "security-admin-console"
}

answered Aug 14 '20 at 08:58

severin.julien

1,314
15
27

If you admit it's the same but uglier then what value does this answer add over the existing one? – ydaetskcoR Aug 14 '20 at 15:02
5

@ydaetskcoR So people can see that there's other way to do things. the answer is interesting because it can help you do others transformation that you wouldn't thought was possible in the first place. – severin.julien Aug 15 '20 at 10:12

Convert list to map with index in Terraform

2 Answers2

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