Terraform: How can I read a value from a json file?

Question

I have this json file (map.json):

[
 {
 "QueueName": "queue1",
 "TypeName": "type1"
 },
 {
 "QueueName": "queue2",
 "TypeName": "type2"
 },
 {
 "QueueName": "queue3",
 "TypeName": "type2"
 }
]

which I can load into the following variable:

locals {
 maps = jsondecode(file("maps.json"))
}

How can I read the TypeName value for QueueName = "queue2"?

Answer 1

I think you are looking at something like this:

type = [for el in local.maps : el["TypeName"] if el["QueueName"] == "queue2"]

Output

$ terraform console
> local.response
[
 "type1",
]

Logically this will return a list of elements, but if you want to retrieve only the first result, then you can use:

response = [for el in local.maps : el["TypeName"] if el["QueueName"] == "queue1"]
type = length(local.response) > 0 ? local.response[0] : ""

Outputs

$ terraform console
> local.type
"type1"
>

Or just:

type = local.maps[index(local.maps.*.QueueName, "queue1")]["TypeName"]

But this will throw an exception if the element queueName does not exist, something like this:

Call to function "index" failed: item not found