Conditional Expressions

A conditional expression uses the value of a boolean expression to select one of two values. If you are familiar with programming languages such as Javascript or Python the Terraform conditional expressions are similar if-else functions.

The syntax of a conditional expression is as follows:

condition ? true_val : false_val

If condition is true then the result is true_val. If condition is false then the result is false_val.

Example #1

In a property rule tree you can set behaviors based on a condition. For example we could apply a caching "no store" when var.environment is "dev":

data "akamai_property_rules_builder" "my_property_rule_caching" {
  rules_v2024_02_12 {
    name                  = "Caching"
    comments              = "Offload Origin"
    criteria_must_satisfy = "any"
    behavior {
      caching {
        behavior        = var.environment == "dev" ? "NO_STORE" : "MAX_AGE"
        must_revalidate = false
        ttl             = "7d"
      }
    }
  }
}

In this scenario when behavior = "NO_STORE" the other arguments for the caching behavior block are ignored. And if the environment is other than dev behavior = "MAX_AGE" gets applied instead.

Example #2

Another common use of conditional expressions in Akamai is for individual or simoultaneous activations in Property Manager:

resource "akamai_property_activation" "my_property_activation_staging" {
  property_id                    = akamai_property.my_property.id
  contact                        = [var.email]
  version                        = var.activate_property_on_staging ? akamai_property.my_property.latest_version : akamai_property.my_property.staging_version
  network                        = "STAGING"
  note                           = var.version_notes
  auto_acknowledge_rule_warnings = true
}
 
resource "akamai_property_activation" "my_property_activation_production" {
  property_id                    = akamai_property.my_property.id
  contact                        = [var.email]
  version                        = var.activate_property_on_staging ? akamai_property.my_property.latest_version : akamai_property.my_property.staging_version
  network                        = "PRODUCTION"
  note                           = var.version_notes
  auto_acknowledge_rule_warnings = true
}

The logic is similar for both activation resources, but let's review the case for the my_property_activation_staging resource:

• If var.activate_property_on_staging is true then the result is akamai_property.my_property.latest_version which holds the latest property version created by the akamai_property resource effectively activting the new version to staging.
• If var.activate_property_on_staging is false then the result is akamai_property.my_property.staging_version which holds the current active version in staging, tricking TF into activate an already activated version effectivelly performing no activation.

Exercise