require-executable

Require Executable Module

This is a module that can be used to ensure particular executables is available in the PATH. This module will search the OS PATH for the provided named executables and validate that it exists, as well as making sure the OS user running terraform has permissions to run the named executable.

This module will exit with an error if any executable in the list does not exist, printing an error message indicating which executables were missing.

This module uses Python under the hood, so Python must be installed and available on the OS.

Example code

See the require-executable example for working sample code.

Conditional check

Sometimes you might want to guard the check for a required executable on a condition (e.g only check if an executable exists if a particular input flag is set). However, Terraform currently does not support conditional module blocks.

For this reason, this module will accept and noop on empty strings as a workaround. For example, suppose you want to check if go is installed based on the condition validate_go. You can achieve this with the following terraform code:

module "require_executables" {
  source = "git::git@github.com:gruntwork-io/terraform-aws-utilities.git//modules/require-executable?ref=v1.0.8"
  required_executables = ["${var.validate_go ? "go" : ""}"]
}