I have the following condition:
resource "aws_elastic_beanstalk_application" "service" {
appversion_lifecycle {
service_role = "service-role"
delete_source_from_s3 = "${var.env == "production" ? false : true}"
}
}
If var.env is set to production, I get the result I want.
However if var.env is not defined, terraform plan will fail because the variable was never defined.
How can I get this to work, without ever having to define that variable?
Seems these days you can also use try to check if something is set.
try(var.env, false)
After that your code will work since var.env is now defined with the value false even if var.env was never defined somewhere.
https://www.terraform.io/docs/configuration/functions/try.html
try function will not catch errors relating to constructs that are provably invalid even before dynamic expression evaluation, such as a malformed reference or a reference to a top-level object that has not been declared. As a result, neither var.non_existent or local.non_existent are supported.
var.env IS defined with a variable block but no values has been set ... probably that's what threw off @t7tranif you are using Terraform 0.12 or later, you can assign the special value null to an argument to mark it as "unset".
variable "env" {
type = "string"
default = null
}
You can't just leave it blank, not with the current versions.
You can have the default of the variable set to an empty string:
variable "env" {
description = "Env where the module is deployed."
type = string
default = ""
}
Once that is done, your check var.env == "production" will produce false and the argument delete_source_from_s3 will be assigned to the value true.
Side note, there is no need for interpolation in the statement,
"${var.env == "production" ? false : true}"
just go with,
delete_source_from_s3 = var.env == "production" ? false : true
https://discuss.hashicorp.com/t/how-do-write-an-if-else-block/2563
delete_source_from_s3 = var.env != "production" is the same