fix: keda_additional_scaling_targets variable

[Uchinda Padmaperuma (uchinda-sph)]

No description provided.

[Uchinda Padmaperuma (uchinda-sph)]

The current implementation of keda_additional_scaling_targets in scaling.tf uses lookup(t, "attribute", default) to access optional fields. While this works for map types, it fails on object types (like the one defined in this PR) if the attribute is missing from the specific instance, even if it's marked as optional in the variable definition.

To make the module truly flexible and resolve the "Unsupported attribute" errors, we should:

1. Replace lookup(t, ...) with try(t.attribute, ...) in scaling.tf.
2. Ensure the variables.tf definition matches the one in this PR to provide the expected schema.

I recommend updating modules/essentials/scaling.tf as well in this PR.

[Uchinda Padmaperuma (uchinda-sph)]

The current implementation of keda_additional_scaling_targets in scaling.tf uses lookup(t, "attribute", default) to access optional fields. While this works for map types, it fails on object types (like the one defined in this PR) if the attribute is missing from the specific instance, even if it's marked as optional in the variable definition.

To make the module truly flexible and resolve the "Unsupported attribute" errors, I recommend updating modules/essentials/scaling.tf to use try() instead:

  # Combine system targets with additional targets
  all_scaling_targets = concat(
    [for t in local.system_scaling_targets : {
      name      = t.name
      namespace = t.namespace
      kind      = t.kind
      replicas  = t.replicas
      enabled   = t.enabled
      triggers = try(t.triggers, [
        {
          type = "cron"
          metadata = {
            timezone        = var.keda_scaling_timezone
            start           = try(t.start, "0 8 * * 1-5")
            end             = try(t.end, "0 20 * * 1-5")
            desiredReplicas = tostring(try(t.replicas, 1))
          }
        }
      ])
    } if t.enabled],
    [for t in var.keda_additional_scaling_targets : {
      name      = t.name
      namespace = t.namespace
      kind      = t.kind
      replicas  = t.replicas
      enabled   = true
      triggers = try(t.triggers, [
        {
          type = "cron"
          metadata = {
            timezone        = var.keda_scaling_timezone
            start           = try(t.start, "0 8 * * 1-5")
            end             = try(t.end, "0 20 * * 1-5")
            desiredReplicas = tostring(try(t.replicas, 1))
          }
        }
      ])
    }]
  )

Note: This change is required because lookup() on an object type strictly requires the attribute to exist in the object's schema. Using try(t.attribute, ...) allows for safe navigation of optional fields and prevents the "Unsupported attribute" errors when users provide inconsistent object structures in the input list.