How do I pass variables to a yaml file in helm.tf?

I have a file for creating terraform resources with helm helm.tf.

In this file I create a honeycomb agent and need to pass in some watchers, so I'm using a yaml file for configuration. Here is the snippet from helm.tf:

resource "helm_release" "honeycomb" {
  version = "0.11.0"
  depends_on = [module.eks]
  repository = "https://honeycombio.github.io/helm-charts"
  chart = "honeycomb"
  name = "honeycomb"

  values = [
    file("modules/kubernetes/helm/honeycomb.yml")
  ]
}

and here is the yaml file

agent:
  watchers:
    - labelSelector: "app=my-app"
      namespace: my-namespace
      dataset: {{$env}}
      parser:
        name: nginx
        dataset: {{$env}}
        options:
          log_format: "blah"

Unfortunately my attempt at setting the variables with {{$x}} has not worked, so how would I send the env variable to the yaml values file? I have the variable available to me in the tf file but am unsure how to set it up in the values file.

Thanks

You may use templatefile function

main.tf

resource "helm_release" "honeycomb" {
  version    = "0.11.0"
  depends_on = [module.eks]
  repository = "https://honeycombio.github.io/helm-charts"
  chart      = "honeycomb"
  name       = "honeycomb"

  values = [
    templatefile("modules/kubernetes/helm/honeycomb.yml", { env = "${var.env}" })
  ]
}

honeycomb.yml

agent:
  watchers:
    - labelSelector: "app=my-app"
      namespace: my-namespace
      dataset: "${env}"
      parser:
        name: nginx
        dataset: "${env}"
        options:
          log_format: "blah"