Process variables in Yaml in Terraform

Question

I am trying to use this module:

https://github.com/philips-labs/terraform-aws-github-runner/blob/main/modules/multi-runner/runners.tf

This is my yaml

matcherConfig:
  exactMatch: true
  labelMatchers:
    - [self-hosted, linux, arm64, amazon]
fifo: true
delay_webhook_event: 0
redrive_build_queue:
  enabled: false
  maxReceiveCount: null
runner_config:
  runner_os: linux
  runner_architecture: arm64
  runner_extra_labels: "ubuntu,amd64,default"
  runner_group_name: default
  runner_name_prefix: amazon-arm64_
  enable_organization_runners: true
  enable_runner_binaries_syncer: false
  enable_ssm_on_runners: true
  block_device_mappings: ${block_device_mappings}
  pool_runner_owner: "${pool_org}"
  pool_config: ${(pool_config)}
  runner_run_as: "ghrunner"
  create_service_linked_role_spot: true
  runner_iam_role_managed_policy_arns: "${managed_policy_arns}"
  runner_metadata_options:
    http_endpoint : enabled
    http_put_response_hop_limit : 1
    http_tokens : required
    instance_metadata_tags : enabled
  enable_jit_config: false
  instance_types:
    - c4.xlarge

I have defined locals as

locals {
  # Load runner configurations from Yaml files
  multi_runner_config = {
    for c in fileset("${path.module}/templates/runner-configs", "*.yaml") :
    trimsuffix(c, ".yaml") => {
      config = yamldecode(templatefile("${path.module}/templates/runner-configs/${c}", {
        pool_runner_owner                   = var.pool_org,
        pool_config                         = jsonencode(var.pool_config),
        runner_iam_role_managed_policy_arns = jsonencode(var.managed_policy_arns),
        block_device_mappings               = jsonencode(var.block_device_mappings),
        ami_owners                          = jsonencode(var.ami_owners)
        ami_filter                          = jsonencode(var.ami_filter)
      }))
    }
  }

}

getting error

  Error: 2023-09-29T17:52:14.696Z [ERROR] vertex "local.multi_runner_config" error: Invalid function argument
  Error: -29T17:52:14.696Z [ERROR] vertex "local.multi_runner_config" error: Invalid function argument
  Error: -29T17:52:14.696Z [ERROR] vertex "local.multi_runner_config (expand)" error: Invalid function argument
  Error: -29T17:52:14.696Z [ERROR] vertex "local.multi_runner_config (expand)" error: Invalid function argument
  ╷
  │ Error: Invalid function argument
  │ 
  │   on variables.tf line 168, in locals:
  │  168:       config = yamldecode(templatefile("${path.module}/templates/runner-configs/${c}", {
  │  169:         pool_runner_owner                   = var.pool_org,
  │  170:         pool_config                         = jsonencode(var.pool_config),
  │  171:         runner_iam_role_managed_policy_arns = jsonencode(var.managed_policy_arns),
  │  172:         block_device_mappings               = jsonencode(var.block_device_mappings),
  │  173:         ami_owners                          = jsonencode(var.ami_owners)
  │  174:         ami_filter                          = jsonencode(var.ami_filter)
  │  175:       }))
  │     ├────────────────
  │     │ var.ami_filter is a map of list of string
  │     │ var.ami_owners is a list of string
  │     │ var.block_device_mappings is a list of object
  │     │ var.managed_policy_arns is a list of string
  │     │ var.pool_config is a list of object
  │     │ var.pool_org is a string
  │ 
  │ Invalid value for "vars" parameter: vars map does not contain key
  │ "pool_org", referenced at
  │ ./templates/runner-configs/linux-arm64.yaml:20,25-33.

How can I solve this issue.

Answer 1

This can be fixed by resolving the naming conflict between the variable name in the template content and the templatefile second parameter argument. Either update the template via:

pool_runner_owner: "${pool_runner_owner}"

or the second parameter map entry via:

pool_org = var.pool_org