How to create a dynamic definition for AWS state machine on Terraform?

I'm trying to create a definition for AWS state machine generating it from this list of object:

state_object_list = [ { name = "task1", type = "Task", resource = "arn:aws:lambda:us-east-1:123456789:function:test", end = false }, { name = "task2", type = "Task", resource = "arn:aws:lambda:us-east-1:1234567890:function:test2", end = true } ] 

I would like to have something similar to this, so with the possibility to define dinamically the key and the values of each state.

resource "aws_sfn_state_machine" "this" { name = "my-state" role_arn = "my-role" definition = jsonencode({ Comment = var.definition_comment StartAt = var.definition_startat States = { for state in var.state_object_list: { state.name = { Type = state.type Resource = state.resource End = state.end } } } }) } 

Is it possible? Thank you for the help.

2 Answers

Can you explain why you want this? The state machine definition follows JSON format so putting your JSON object into the definition=jsonencode({...}) with minor adjustments to follow the Amazon States Language syntax should work and doesn't create more complexity in the code. Maybe I missed your point.

Easiest way to accomplish this issue to create a local variable then use it in your resource.

variables.tf

variable "state_object_list" { default = [ { name = "task1", type = "Task", resource = "arn:aws:lambda:us-east-1:123456789:function:test", end = false }, { name = "task2", type = "Task", resource = "arn:aws:lambda:us-east-1:1234567890:function:test2", end = true } ] } variable "definition_comment" { type = string default = "definition comment" } variable "definition_startat" { type = string default = "definition state" } 

main.tf

locals { states = { for state in var.state_object_list: state.name => { Type = state.type Resource = state.resource End = state.end } } } resource "aws_sfn_state_machine" "this" { name = "my-state" role_arn = "arn:aws:iam::123456789098:role/my-role" definition = jsonencode({ Comment = var.definition_comment StartAt = var.definition_startat States = local.states }) }