04-modules.md

Modules

Modules are first class citizens in terraform. They are easy to write and use and can be referenced from the code but also from git repositories or from https://registry.terraform.io. This part demonstrates how to move from a set of resources into a module:

• create a new stack, here modules/public-network and move all the resources into it.
• remove these same resources from the original terraform directory.
• in the module, for each value that cannot be accessed, directly from it, create a variable, for instance, create a variable for the compartment
• if you want to use other parameter, like naming the module, add additional variables
• if you need the module to provide outputs, like the subnet identifiers, add an output to export them
• in the main project, reference the module with the module directory as as source like below:

module "livecode" {
  compartment = "${var.compartment}"
  name = "livecode"
  source = "../modules/public-network"
}

• if you need to access some module output, just reference them by their name like module.livecode.public_subnets in this case.
• to use the module, you should run terraform init again. Once done, you can simply apply or destroy the module.

You can move to the next section of this demonstration by running the command below:

git checkout -b 05-demo origin/05-demo