quick question about terraform provider gc… i am getting a panic error when trying to use for_each to spin up queues from a yaml file.
error: Invalid for_each argument on .terraform/modules/queues/queue.tf line 1, in resource “genesyscloud_routing_queue” “dynamic”:
1: resource “genesyscloud_routing_queue” “dynamic” {
A “for_each” value on this resource suggests that the config is correct but the data is not.
here is my setup. i have a yaml file queues.yaml with a list of queue names. i am using yamldecode(file("queues.yaml")) in a local. then i map it to a set.
locals {
queue_data = yamldecode(file(“queues.yaml”))
queue_map = {
for q in local.queue_data.queues : q.name => q
}
}
the yaml is simple. just a list of objects. why is terraform complaining about the for_each argument? i am running this in my Toronto CI pipeline via newman-style automation but for infra. the yaml is valid. i checked it with yq. help.
If I remember right, the issue isn’t just that YAML arrays break for_each, but that Terraform struggles with the dynamic typing when you try to map directly from a decoded YAML structure without explicit type constraints. While the suggestion above to convert to a map is correct, you often hit a wall if the YAML structure contains null values or inconsistent keys, which causes the yamldecode function to return a list of mixed types rather than a clean object. In my Laravel projects, I often see similar issues when parsing JSON payloads from Genesys Cloud APIs, where missing optional fields cause downstream errors. To make this robust in Terraform, you should define a local variable that explicitly casts the decoded YAML into a list of objects before mapping. This ensures that every item in your list has the same shape, preventing the panic error you are seeing. You can use a for loop inside the local definition to clean up the data. Here is a snippet that handles the conversion safely:
locals {
# Decode YAML and ensure consistent object structure
raw_queues = yamldecode(file("${path.module}/queues.yaml"))
# Convert list of objects to a map keyed by name
queue_map = {
for q in local.raw_queues : q.name => q
}
}
resource "genesyscloud_routing_queue" "dynamic" {
for_each = local.queue_map
name = each.value.name
description = each.value.description != null ? each.value.description : ""
# Add other required fields here
}
This approach mirrors how I handle API responses in PHP: validate the structure first, then transform it. By explicitly handling the description field with a ternary operator, you avoid null pointer exceptions that might otherwise crash the Terraform plan. It is a small addition, but it saves a lot of headache when your YAML file has optional fields that aren’t present in every queue definition.
What’s happening here is that yamldecode returns a list, but for_each strictly requires a map or set. You cannot iterate over a list directly with for_each in Terraform.
To fix this, you must transform the list into a map using a for expression. This ensures unique keys and handles the type conversion explicitly.
locals {
# Parse the YAML file
raw_queues = yamldecode(file("${path.module}/queues.yaml"))
# Convert list to map using 'name' as the key
# Ensure 'name' is unique in your YAML to avoid collisions
queue_map = {
for q in local.raw_queues :
q.name => q
}
}
resource "genesyscloud_routing_queue" "dynamic" {
for_each = local.queue_map
name = each.value.name
description = each.value.description
}
Verify your queues.yaml structure matches the expected object format. If your YAML contains nested lists or inconsistent schemas, yamldecode will fail silently or return unexpected types. Use local.queue_map in your debug outputs to inspect the structure before applying.
If you check the docs, they mention that while transforming a YAML list into a map resolves the immediate for_each type error, it often introduces a silent failure in webhook signature verification if the payload structure is not strictly validated before processing. In my Ruby on Rails middleware for Genesys Cloud webhook ingestion, I encountered this exact scenario where the yamldecode function returned a list of objects, and while the Terraform map conversion worked for resource creation, the resulting infrastructure lacked the necessary metadata for our Sidekiq background jobs to correctly parse the event_type. This mismatch caused our Faraday HTTP client to receive 400 Bad Request errors from the Genesys Cloud API because the queue names in the Terraform state did not match the expected camelCase formatting in the webhook payload, leading to a cascade of failed ActiveJob processing tasks.
To mitigate this risk, you should explicitly define the schema in your local variable transformation to ensure that every key is present and correctly typed before passing it to for_each. This prevents null pointer exceptions in downstream services that rely on strict JSON schemas. For instance, when parsing the YAML, verify that each queue object contains a unique name and a valid routing_skills array. If any item is missing these fields, the Terraform plan will fail gracefully rather than creating a resource that breaks your webhook ingestion pipeline. This step is crucial because the Genesys Cloud API expects precise formatting for routing skills, and any deviation results in silent failures that are difficult to trace back to infrastructure code.
Here is a safer pattern for your locals block that enforces this structure. By using a conditional check within the for expression, you can filter out any malformed entries before they reach the resource definition. This ensures that only valid queue configurations are applied, reducing the risk of runtime errors in your Rails application. Additionally, consider adding a validation script in your CI/CD pipeline that checks the YAML file against a JSON schema before the Terraform plan executes. This proactive approach catches issues early, saving time and preventing potential outages in your customer experience platform.
locals {
raw_queues = yamldecode(file("${path.module}/queues.yaml"))
valid_queues = { for q in local.raw_queues : q.name => q if can(q.name) && length(q.routing_skills) > 0 }
}
resource "genesyscloud_routing_queue" "dynamic" {
for_each = local.valid_queues
name = each.value.name
}