Perform extended validation on Terraform configurations, at either plan or apply time.
This aims to address a core limitation of Terraform: validating multiple variables in the same context.
This provider requires no configuration.
provider "validation" {}The validation_error resource can be used to evaluate values only known at apply time, and stop an
in-progress Terraform execution based upon their values.
variable "one" {}
variable "two" {}
resource "validation_error" "error" {
condition = var.one == var.two
summary = "var.one and var.two must never be equal"
details = <<EOF
When var.one and var.two are equal, bad things can happen.
Please use differing values for these inputs.
var.one: ${var.one}
var.two: ${var.two}
EOF
}The validation_warning resource can be used to evaluate values only known at apply time. This resource
will print a message to the user, but not cause the Terraform execution to fail.
This can be useful for deprecation notices, etc.
variable "one" {}
variable "two" {}
resource "validation_warning" "warn" {
condition = var.one == var.two
summary = "var.one and var.two are equal. This will cause an error in future versions"
details = <<EOF
In a future release of this code, var.one and var.two may no longer be equal.
Please consider modifying the values to avoid execution failures.
var.one: ${var.one}
var.two: ${var.two}
EOF
}Each resource above has an accompanying data source, which can be used to show warnings or errors during the plan phase and may not stop an in-progress Terraform execution.