I have a TF resource defined as follows (example is simplified):

resource "kubernetes_deployment" "this" {
  # [... some stuff removed for simplification]
  spec {
    replicas = 3

    # [... more stuff removed]

    template {
      metadata {
        # [... removed]
      }

      spec {
        container {
          name  = local.name
          image = "some_image:some_tag"

          env {
            name  = "SOME_ENV_VARIABLE_1"
            value = "SOME_VALUE"
          }

          env {
            name  = "SOME_ENV_VARIABLE_2"
            value = "SOME_OTHER_VALUE"
          }
[...]
}

When I run the plan for this I get something like the following:

Terraform will perform the following actions:

  # module.my_module.kubernetes_deployment.this will be updated in-place
  ~ resource "kubernetes_deployment" "this" {
        id               = "some/id"
        # (1 unchanged attribute hidden)

      ~ spec {
            # (5 unchanged attributes hidden)

          ~ template {
              ~ spec {
                    # (13 unchanged attributes hidden)

                  ~ container {

                        # [some stuff removed here that isn't important]

                        # (8 unchanged attributes hidden)

                      - env {
                          - name  = "SOME_OTHER_DYNAMICALLY_CREATED_ENV_VARIABLE" -> null
                          - value = "some_value" -> null
                        }

                        # (15 unchanged blocks hidden)
                    }

I’ve been trying to figure out how I can instruct TF to ignore changes to an environment variable named SOME_OTHER_DYNAMICALLY_CREATED_ENV_VARIABLE but not other variables.

The only solution I’ve thought of would be to actually define the SOME_OTHER_DYNAMICALLY_CREATED_ENV_VARIABLE environment variable in my resource as the first env block and then add spec[0].template[0].spec[0].container[0].env[0] to my lifecycle.ignore_changes list.

But that is a very brittle solution to this if somebody accidentally adds an env block before that one.

Is there any way to specify that this environment variable specifically should be ignored?