Add include functionality

[chrisferry]

Would like to follow DRY principles with my TF templates.
I currently have:

resource "terraform_remote_state" "vpc" {
    backend = "consul"
    config {
        address = "consul.domain.com"
        path    = "us-east-1/vpc"
        scheme  = "https"
    }
}

resource "terraform_remote_state" "inf-sg" {
    backend = "consul"
    config {
        address = "consul.domain.com"
        path    = "us-east-1/inf-security-groups"
        scheme  = "https"
    }
}

----- at the top of all my templates

would prefer the ability to use:

include "../../common/tf_remotes.tf"

[ocxo]

Are you looking for something like modules?

[chrisferry]

I use modules already for other functionality, but modules does not solve this use case.

[knuckolls]

I've wanted to be able to define my own resource templates that define defaults.

Something like...

resource_template "aws_instance" "my_aws_instance" {
  ... default values ...
}

resource "my_aws_instance" "foo" {
  ...specific stuff...
}

[ryanuber]

@knuckolls I did something exactly like that in the early TF days. The PR is probably totally not relevant now, but for reference here it is: #232

[knuckolls]

wow cool. modules certainly help dry things up but I feel like resource_templates would improve the readability of a lot of .tf files.

[tomzo]

I agree that modules are not the same.
An include that works more like c++ include would be useful.
It is to reduce text, not a concept in domain like module are.

[eppdot]

I would also love to see this feature in the next tf release. I could also live with a simple C++ include, just copying the template into the tf file.

[kendawg2]

+1

[josephholsten]

@chrisferry what exactly is worse about modules than this straight string include? Would it be sufficient to have a shorthand for modules like

module "../../common/tf_remotes"

with the common code in common/tf_remotes/main.tf?

[tomzo]

what exactly is worse about modules than this straight string include?

I guess modules let you include whole sets of resources, you can use them at root level of terraform file.
include could be within resource so that you can have part of resource defined in separate file.

[kendawg2]

@josephholsten So my issue with modules (and perhaps I am not using them correctly) is needing to provide all of the extra logic for exporting and importing variables. If we look at the simplest terraform configuration, we would have a Variables.tf and a main.tf. The main would have all of the resources in it and Variables would be populated as needed from Variables.tf (or from within the main.tf file). All resources inherit those variables naturally.

To make it bit more readable, I have taken all of the servers and security groups etc, and made separate files of them. Because they are in the same directory, they get loaded automatically, just as though they were in the main.tf file, and thus naturally inherit all of the variables and pass information to each other without issue.

I have about a dozen environments where I have the exact same configuration, but some things change, like some are missing a few services, or the security groups are a bit different, but by and large the variables used are all the same, the values are the only difference.

What I would like to do, is have a tfvars file which is unique to each environment, and then create a main.tf which might have some tweaks or might be the same, but then include files from a master directory just as though they were in the current directory, but only the ones I want. I do that today by simply copying entire directories around and then making the tf files t_ files so they don't load if I don't want them to. I don't have to pass in variables, they just get loaded.

If I use modules, then I have to pass in and out variables, plus they get copied into a hidden directory anyway. With an include, they would just get loaded as needed. I know this could create some versioning issues, but that would be for the user to decide as they do now.

I believe this functionality existed in some form early on, but was removed. IMHO I think it's easy to do and a great option that would drastically reduce the number of times my files are copied around, even using modules. A module is like 5-10 lines of code in my main.tf while an include is one.

[stefanthorpe]

+1 for include
would make linking super simple. Modules have there part but are overkill in some cases

[danielcbright]

👍 for include, this is a feature sorely needed