I'm using Terraform in a modular fashion in order to build out my infrastructure. I do this by having a configuration file that calls in the different modules. I want to pass an infrastructure variable which picks up what tagged version of the Github repository the application should be building out. Most importantly I'm trying to figure out how to make a concatenation of a string happen in the "source" variable of the configuration file.
module "athenaelb" {
source = "${concat("git::https://github.com/ORG/REPONAME.git?ref=",var.infra_version)}"
aws_access_key = "${var.aws_access_key}"
aws_secret_key = "${var.aws_secret_key}"
aws_region = "${var.aws_region}"
availability_zones = "${var.availability_zones}"
subnet_id = "${var.subnet_id}"
security_group = "${var.athenaelb_security_group}"
branch_name = "${var.branch_name}"
env = "${var.env}"
sns_topic = "${var.sns_topic}"
s3_bucket = "${var.elb_s3_bucket}"
athena_elb_sns_topic = "${var.athena_elb_sns_topic}"
infra_version = "${var.infra_version}"
}
I want it to compile and for the source to look like this (for example): git::https://github.com/ORG/REPONAME.git?ref=v1
Anyone have any thoughts on how to make this work?
Thanks, Keren
This is not possible currently in Terraform itself.
The only way to achieve something like this is to use a separate script to interact with the git repository that Terraform clones into a subdirectory of the .terraform/modules directory and switch it to a different tag depending on which version you need. This is non-ideal since Terraform organizes these into directories based on a hash of the module path, but if you can identify the module in question it is safe to run git checkout within these repositories as long as you do not run terraform get again afterwards.
For more details and discussion on this issue, see issue #1439 in Terraform's issue tracker, where this feature was requested.